![Page 1: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/1.jpg)
66The Muscular SystemThe Muscular System
Yong Jeong, MD, PhDg g
Department of Bio and Brain Engineering
![Page 2: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/2.jpg)
© 2012 Pearson Education, Inc.
![Page 3: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/3.jpg)
The Muscular System
•Muscles are responsible for all types of body movement
•Three basic muscle types are found in theThree basic muscle types are found in the body
Sk l t l l•Skeletal muscle•Cardiac muscle•Smooth muscle
© 2012 Pearson Education, Inc.
![Page 4: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/4.jpg)
Characteristics of Muscles
•Skeletal and smooth muscle cells are elongated (muscle cell = muscle fiber)
•Contraction and shortening of muscles is dueContraction and shortening of muscles is due to the movement of microfilamentsAll l h t i l•All muscles share some terminology•Prefixes myo and mys refer to “muscle”y y•Prefix sarco refers to “flesh”
© 2012 Pearson Education, Inc.
![Page 5: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/5.jpg)
© 2012 Pearson Education, Inc. Table 6.1
![Page 6: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/6.jpg)
Comparison of Skeletal, Cardiac, and Smooth Muscles
Ch t i ti Sk l t l C di S thCharacteristic Skeletal Cardiac Smooth
Body location Attached to bone or skin (for some
Walls of the heart Mostly in walls of visceral organsor skin (for some
facial muscles)visceral organs (other than the heart)
Cell shape and appearance
Single, very long, cylindrical, multinucleate
Branching chains of cells, uninucleate,
Single, fusiform, uninucleate, no striations
cells with very obvious striations
striations, intercalated discs
Connective Endomysium Endomysium EndomysiumConnective tissue components
Endomysium, perimysium, and epimysium
Endomysium Endomysium
© 2012 Pearson Education, Inc.
![Page 7: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/7.jpg)
Comparison of Skeletal, Cardiac, and Smooth Muscles
Ch t i ti Sk l t l C di S thCharacteristic Skeletal Cardiac Smooth
Regulation of contraction
Voluntary Involuntary Involuntarycontraction
Speed of contraction
Slow to fast Slow Very slow
Rhythmic No Yes Yes in someRhythmic contractions
No Yes Yes, in some
© 2012 Pearson Education, Inc.
![Page 8: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/8.jpg)
Skeletal Muscle Characteristics
•Most are attached by tendons to bones•Cells are multinucleateStriated have visible banding•Striated—have visible banding
•Voluntary—subject to conscious control
© 2012 Pearson Education, Inc.
![Page 9: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/9.jpg)
Connective Tissue Wrappings of Skeletal Muscle
•Cells are surrounded and bundled by connective tissue•Endomysium—encloses a single muscle fiberfiber
•Perimysium—wraps around a fascicle (bundle) of muscle fibers
•Epimysium—covers the entire skeletalEpimysium covers the entire skeletal muscleFascia on the outside of the epimysium
© 2012 Pearson Education, Inc.
•Fascia—on the outside of the epimysium
![Page 10: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/10.jpg)
Musclefiber
Blood vessel
Perimysium
(cell)
Epimysium(wraps entire( pmuscle)
Fascicle(wrapped by(wrapped byperimysium)
Endomysium(betweenfibers)
T dTendon
Bone
© 2012 Pearson Education, Inc. Figure 6.1
![Page 11: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/11.jpg)
Skeletal Muscle Attachments
•Epimysium blends into a connective tissue attachment•Tendons—cord-like structuresTendons cord like structures
•Mostly collagen fibers•Often cross a joint due to toughness and small size
•Aponeuroses—sheet-like structuresAtt h l i di tl t b•Attach muscles indirectly to bones, cartilages, or connective tissue coverings
© 2012 Pearson Education, Inc.
![Page 12: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/12.jpg)
Skeletal Muscle Attachments
•Sites of muscle attachment•BonesCartilages•Cartilages
•Connective tissue coverings
© 2012 Pearson Education, Inc.
![Page 13: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/13.jpg)
Smooth Muscle Characteristics
•Lacks striations•Spindle-shaped cellsSingle nucleus•Single nucleus
•Involuntary—no conscious control•Found mainly in the walls of hollow organs
© 2012 Pearson Education, Inc.
![Page 14: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/14.jpg)
Circular layerof smooth muscle(longitudinal viewof cells)Mucosa
Longitudinal layerLongitudinal layerof smooth muscle(cross-sectionali f ll )
Submucosa
© 2012 Pearson Education, Inc. Figure 6.2a
view of cells)(a)
![Page 15: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/15.jpg)
Cardiac Muscle Characteristics
•Striations•Usually has a single nucleusBranching cells•Branching cells
•Joined to another muscle cell at an intercalated disc
•InvoluntaryInvoluntary•Found only in the walls of the heart
© 2012 Pearson Education, Inc.
![Page 16: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/16.jpg)
Cardiacmusclemusclebundles
© 2012 Pearson Education, Inc. Figure 6.2b(b)
![Page 17: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/17.jpg)
Skeletal Muscle Functions
•Produce movement•Maintain postureStabilize joints•Stabilize joints
•Generate heat
© 2012 Pearson Education, Inc.
![Page 18: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/18.jpg)
Microscopic Anatomy of Skeletal Muscle
•Sarcolemma—specialized plasma membrane•Myofibrils—long organelles inside muscle cellSarcoplasmic reticulum specialized smooth•Sarcoplasmic reticulum—specialized smooth endoplasmic reticulum
© 2012 Pearson Education, Inc.
![Page 19: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/19.jpg)
Cytoplasmic Organelles
•Cytoskeleton•Three different types of elements•Microfilaments I t di t•Intermediate filaments
•Microtubules
© 2012 Pearson Education, Inc.
Figure 3.7b–d
![Page 20: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/20.jpg)
Sarcolemma
Myofibril
Dark(A) band
Light(I) band
Nucleus
(a) Segment of a muscle fiber (cell)
© 2012 Pearson Education, Inc. Figure 6.3a
![Page 21: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/21.jpg)
Microscopic Anatomy of Skeletal Muscle
•Myofibrils are aligned to give distinct bands•I band = light band
Contains only thin filaments•Contains only thin filaments•A band = dark band
•Contains the entire length of the thick filamentsfilaments
© 2012 Pearson Education, Inc.
![Page 22: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/22.jpg)
Z disc H zone Z disc
Thin (actin) filamentThick (myosin) filament
(b) Myofibril or fibril(complex organelle
I band A band I band M line(complex organellecomposed of bundlesof myofilaments)
© 2012 Pearson Education, Inc. Figure 6.3b
![Page 23: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/23.jpg)
Microscopic Anatomy of Skeletal Muscle
•Sarcomere—contractile unit of a muscle fiber•Organization of the sarcomere
Myofilaments•Myofilaments•Thick filaments = myosin filaments•Thin filaments = actin filaments
© 2012 Pearson Education, Inc.
![Page 24: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/24.jpg)
Microscopic Anatomy of Skeletal Muscle
•Thick filaments = myosin filaments•Composed of the protein myosin•Has ATPase enzymesHas ATPase enzymes•Myosin filaments have heads (extensions, or cross bridges)cross bridges)
•Myosin and actin overlap somewhat•Thin filaments = actin filaments
•Composed of the protein actinp p•Anchored to the Z disc
© 2012 Pearson Education, Inc.
![Page 25: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/25.jpg)
Z di
Sarcomere
M lineZ diZ disc Z disc
Thin (actin) filament
Thick (myosin) filament
(c) Sarcomere (segment of a myofibril)
© 2012 Pearson Education, Inc. Figure 6.3c
![Page 26: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/26.jpg)
Microscopic Anatomy of Skeletal Muscle
•At rest, within the A band there is a zone that lacks actin filaments •Called either the H zone or bare zoneCalled either the H zone or bare zone
•Sarcoplasmic reticulum (SR) •Stores and releases calcium•Surrounds the myofibrilSurrounds the myofibril
© 2012 Pearson Education, Inc.
![Page 27: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/27.jpg)
Thick filament Bare zone Thin filament
(d) Myofilament structure (within one sarcomere)
© 2012 Pearson Education, Inc. Figure 6.3d
![Page 28: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/28.jpg)
Stimulation and Contraction of Single Skeletal Muscle Cells
•Excitability (also called responsiveness or irritability)—ability to receive and respond to a y) y pstimulus
•Contractility ability to shorten when an•Contractility—ability to shorten when an adequate stimulus is received
•Extensibility—ability of muscle cells to be stretched
•Elasticity—ability to recoil and resume resting length after stretching
© 2012 Pearson Education, Inc.
length after stretching
![Page 29: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/29.jpg)
The Nerve Stimulus and Action Potential
•Skeletal muscles must be stimulated by a motor neuron (nerve cell) to contract
•Motor unit—one motor neuron and all theMotor unit one motor neuron and all the skeletal muscle cells stimulated by that neuron
© 2012 Pearson Education, Inc.
![Page 30: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/30.jpg)
Spinal cordAxon terminals at neuromuscular junctions
Motor unit 1
Motor unit 2unit 1 unit 2
Nerve
Axon ofmotorMotor neuron
cell bodies neuroncell bodies
Muscle Muscle fibers
© 2012 Pearson Education, Inc. Figure 6.4a(a)
![Page 31: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/31.jpg)
Axon terminals at neuromuscular junctions Muscle fibers
Branching axonto motor unit
© 2012 Pearson Education, Inc. Figure 6.4b
(b)
![Page 32: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/32.jpg)
The Nerve Stimulus and Action Potential
•Neuromuscular junction•Association site of axon terminal of the motor neuron and musclemotor neuron and muscle
PLAY A&P Flix™: Events at the Neuromuscular Junction
© 2012 Pearson Education, Inc.
![Page 33: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/33.jpg)
© 2012 Pearson Education, Inc. Figure 6.5
![Page 34: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/34.jpg)
The Nerve Stimulus and Action Potential
•Synaptic cleft •Gap between nerve and muscleNerve and muscle do not make contact•Nerve and muscle do not make contact
•Area between nerve and muscle is filled with interstitial fluid
•Action potential reaches the axon terminal ofAction potential reaches the axon terminal of the motor neuronC l i h l d l i i t•Calcium channels open and calcium ions enter the axon terminal
© 2012 Pearson Education, Inc.
![Page 35: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/35.jpg)
Transmission of Nerve Impulse to Muscle
•Calcium ion entry causes some synaptic vesicles to release their contents (acetylcholine, a neurotransmitter) by ( y , ) yexocytosis
•Neurotransmitter chemical released by nerve•Neurotransmitter—chemical released by nerve upon arrival of nerve impulse in the axon terminalterminal•The neurotransmitter for skeletal muscle is acetylcholine (ACh)
© 2012 Pearson Education, Inc.
![Page 36: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/36.jpg)
Transmission of Nerve Impulse to Muscle
•Acetylcholine attaches to receptors on the sarcolemma of the muscle cell
•In response to the binding of ACh to aIn response to the binding of ACh to a receptor, the sarcolemma becomes permeable to sodium (Na+)to sodium (Na )
•Sodium rushes into the cell generating an action potential and potassium leaves the cell
•Once started, muscle contraction cannot beOnce started, muscle contraction cannot be stopped
© 2012 Pearson Education, Inc.
![Page 37: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/37.jpg)
S naptic esicle containing AChSynaptic vesicle containing ACh
Axon terminal of motor neuronMitochondrion
Action potential reaches axonterminal of motor neuron.1
Ca2+
Synapticcleft
Sarcolemma
Fusing synaptic
Ca2+
Fusing synapticvesicleSarcoplasmof muscle fiberFolds of
lACh
ACh
sarcolemmareceptor
© 2012 Pearson Education, Inc. Figure 6.5, step 1
![Page 38: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/38.jpg)
S naptic esicle containing AChSynaptic vesicle containing ACh
Axon terminal of motor neuronMitochondrion
Action potential reaches axonterminal of motor neuron.1
Ca2+
Fusing synaptic
Ca2+
SarcolemmaSynapticcleft
Calcium (Ca2+) channelsopen and Ca2+ enters the axon terminal.
2
Fusing synapticvesicleSarcoplasmof muscle fiberFolds of
lACh
ACh
sarcolemmareceptor
© 2012 Pearson Education, Inc. Figure 6.5, step 2
![Page 39: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/39.jpg)
S naptic esicle containing AChSynaptic vesicle containing ACh
Axon terminal of motor neuronMitochondrion
Action potential reaches axonterminal of motor neuron.1
Ca2+
Fusing synaptic
Ca2+
SarcolemmaSynapticcleft
Calcium (Ca2+) channelsopen and Ca2+ enters the axon terminal.
2
Fusing synapticvesicleSarcoplasmof muscle fiberFolds of
lACh
AChCa2+ entry causes somesynaptic vesicles to release theircontents (acetylcholine a
3
sarcolemmareceptorcontents (acetylcholine, a neurotransmitter) by exocytosis.
© 2012 Pearson Education, Inc. Figure 6.5, step 3
![Page 40: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/40.jpg)
S naptic esicle containing AChAction potential reaches axon
terminal of motor neuron.
Synaptic vesicle containing ACh
Axon terminal of motor neuronMitochondrion
1
Calcium (Ca2+) channelsopen and Ca2+ enters the axon terminal.
Ca2+
Fusing synaptic
Ca2+2
SarcolemmaSynapticcleft
Ca2+ entry causes somesynaptic vesicles to release theircontents (acetylcholine a
Fusing synapticvesicleSarcoplasmof muscle fiberFolds of
lACh
ACh3
contents (acetylcholine, a neurotransmitter) by exocytosis.
Acetylcholine diffuses acrossthe synaptic cleft and binds toreceptors in the sarcolemma.
sarcolemmareceptor
4
p
© 2012 Pearson Education, Inc. Figure 6.5, step 4
![Page 41: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/41.jpg)
ACh binds and channels openthat allow simultaneous passageof Na+ into the muscle fiber and K+ out of the muscle fiber. More
5Ion channel insarcolemma opens;ions pass.
Na+ K+
Na+ ions enter than K+ ions leaveand this produces a local changein the electrical conditions of themembrane (depolarization), whicheventually leads to an actioneventually leads to an actionpotential.
© 2012 Pearson Education, Inc. Figure 6.5, step 5
![Page 42: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/42.jpg)
ACh effects are ended by its6
Ion channel closed;ions cannot pass.Na+
Degraded AChACh
ACh effects are ended by itsbreakdown in the synaptic cleft bythe enzyme acetylcholinesterase.
6
AcetylcholinesteraseK+
© 2012 Pearson Education, Inc. Figure 6.5, step 6
![Page 43: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/43.jpg)
© 2012 Pearson Education, Inc.
![Page 44: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/44.jpg)
S ll t i
Neuromuscular junction
NerveMuscle cellor fiber
Small twig
Match
Nervefiber Striations
Matchflame
Flame ignites the twig.
Flame spreads rapidly along the twig.
Na+ diffusesinto the cell. Action potential spreads
rapidly along the sarcolemma.1 2
12
(b)(a)
© 2012 Pearson Education, Inc. Figure 6.6a-b
![Page 45: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/45.jpg)
© 2012 Pearson Education, Inc.
![Page 46: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/46.jpg)
The Sliding Filament Theory of Muscle Contraction
A i i b i h d•Activation by nerve causes myosin heads (cross bridges) to attach to binding sites on the thin filament
•Myosin heads then bind to the next site of theMyosin heads then bind to the next site of the thin filament and pull them toward the center of the sarcomereof the sarcomere
•This continued action causes a sliding of the i l h imyosin along the actin
•The result is that the muscle is shortened
© 2012 Pearson Education, Inc.
(contracted)
![Page 47: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/47.jpg)
Myosin Actin
Z ZZ HI
ZA I
(a)(a)
Z Z
© 2012 Pearson Education, Inc. Figure 6.7a–b(b)
ZI A I
Z
![Page 48: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/48.jpg)
Protein complex In a relaxed muscle cell, the regulatory proteins formingp In a relaxed muscle cell, the regulatory proteins formingpart of the actin myofilaments prevent myosin binding(see a). When an action potential (AP) sweeps along itssarcolemma and a muscle cell is excited, calcium ions(Ca2+) are released from intracellular storage areas (the
f th l i ti l )
Myosinmyofilament
Actinmyofilament(a)
sacs of the sarcoplasmic reticulum).
© 2012 Pearson Education, Inc. Figure 6.8a
![Page 49: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/49.jpg)
Myosin-binding site C 2 The flood of calcium acts as the final trigger forMyosin binding site Ca2+ The flood of calcium acts as the final trigger forcontraction, because as calcium binds to the regulatoryproteins on the actin filaments, the proteins undergo a change in both their shape and their position on the thinfilaments. This action exposes myosin-binding sites on
Upper part of thick filament only(b)
y gthe actin, to which the myosin heads can attach (see b),and the myosin heads immediately begin seeking out binding sites.
© 2012 Pearson Education, Inc. Figure 6.8b
![Page 50: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/50.jpg)
PLAY A&P Flix™: The Cross Bridge Cycle
© 2012 Pearson Education, Inc. Figure 6.8c
![Page 51: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/51.jpg)
© 2012 Pearson Education, Inc.
![Page 52: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/52.jpg)
Contraction of Skeletal Muscle
•Muscle fiber contraction is “all or none”•Within a skeletal muscle, not all fibers may be stimulated during the same intervalstimulated during the same interval
•Different combinations of muscle fiber t ti i diff icontractions may give differing responses
•Graded responses—different degrees of p gskeletal muscle shortening
© 2012 Pearson Education, Inc.
![Page 53: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/53.jpg)
Contraction of Skeletal Muscle
•Graded responses can be produced by changing:•The frequency of muscle stimulationThe frequency of muscle stimulation•The number of muscle cells being stimulated
t tiat one time
© 2012 Pearson Education, Inc.
![Page 54: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/54.jpg)
Types of Graded Responses
•Twitch•Single, brief contractionNot a normal muscle function•Not a normal muscle function
© 2012 Pearson Education, Inc.
![Page 55: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/55.jpg)
© 2012 Pearson Education, Inc. Figure 6.9a
![Page 56: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/56.jpg)
Types of Graded Responses
•Summing of contractions•One contraction is immediately followed by anotheranother
•The muscle does not completely return to a ti t t d t f tresting state due to more frequent
stimulations•The effects are added
© 2012 Pearson Education, Inc.
![Page 57: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/57.jpg)
© 2012 Pearson Education, Inc. Figure 6.9b
![Page 58: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/58.jpg)
Types of Graded Responses
•Unfused (incomplete) tetanus•Some relaxation occurs between contractions but nerve stimuli arrive at ancontractions but nerve stimuli arrive at an even faster rate than during summing of contractionscontractions
•Unless the muscle contraction is smooth and sustained, it is said to be in unfused tetanus
© 2012 Pearson Education, Inc.
![Page 59: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/59.jpg)
© 2012 Pearson Education, Inc. Figure 6.9c
![Page 60: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/60.jpg)
Types of Graded Responses
•Fused (complete) tetanus•No evidence of relaxation before the following contractionsfollowing contractions
•Frequency of stimulations does not allow for l ti b t t tirelaxation between contractions
•The result is a smooth and sustained muscle contraction
© 2012 Pearson Education, Inc.
![Page 61: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/61.jpg)
© 2012 Pearson Education, Inc. Figure 6.9d
![Page 62: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/62.jpg)
Muscle Response to Strong Stimuli
•Muscle force depends upon the number of fibers stimulated
•More fibers contracting results in greaterMore fibers contracting results in greater muscle tensionM l ti t t t l th•Muscles can continue to contract unless they run out of energy
© 2012 Pearson Education, Inc.
![Page 63: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/63.jpg)
Energy for Muscle Contraction
•Initially, muscles use stored ATP for energy•ATP bonds are broken to release energyOnly 4 6 seconds worth of ATP is stored by•Only 4–6 seconds worth of ATP is stored by muscles
•After this initial time, other pathways must be utilized to produce ATPp
© 2012 Pearson Education, Inc.
![Page 64: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/64.jpg)
Energy for Muscle Contraction
•Direct phosphorylation of ADP by creatine phosphate (CP)•Muscle cells store CPMuscle cells store CP
•CP is a high-energy molecule•After ATP is depleted, ADP is left•CP transfers a phosphate group to ADP toCP transfers a phosphate group to ADP, to regenerate ATPCP li h t d i l th 15•CP supplies are exhausted in less than 15 seconds
© 2012 Pearson Education, Inc.
•About 1 ATP is created per CP molecule
![Page 65: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/65.jpg)
© 2012 Pearson Education, Inc. Figure 6.10a
![Page 66: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/66.jpg)
Energy for Muscle Contraction
•Aerobic respiration•Glucose is broken down to carbon dioxide and water releasing energy (about 32 ATP)and water, releasing energy (about 32 ATP)
•A series of metabolic pathways occur in the it h d imitochondria
•This is a slower reaction that requires qcontinuous oxygen
•Carbon dioxide and water are produced•Carbon dioxide and water are produced
© 2012 Pearson Education, Inc.
![Page 67: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/67.jpg)
© 2012 Pearson Education, Inc. Figure 6.10c
![Page 68: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/68.jpg)
Energy for Muscle Contraction
•Anaerobic glycolysis and lactic acid formation•Reaction that breaks down glucose withoutoxygenoxygen
•Glucose is broken down to pyruvic acid to d b t 2 ATPproduce about 2 ATP
•Pyruvic acid is converted to lactic acidy•This reaction is not as efficient, but is fast
H t f l d d•Huge amounts of glucose are needed•Lactic acid produces muscle fatigue
© 2012 Pearson Education, Inc.
p g
![Page 69: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/69.jpg)
© 2012 Pearson Education, Inc. Figure 6.10b
![Page 70: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/70.jpg)
Muscle Fatigue and Oxygen Deficit
•When a muscle is fatigued, it is unable to contract even with a stimulus
•Common cause for muscle fatigue is oxygenCommon cause for muscle fatigue is oxygen debt
O t b “ id” t ti t•Oxygen must be “repaid” to tissue to remove oxygen deficit
•Oxygen is required to get rid of accumulated lactic acidlactic acid
•Increasing acidity (from lactic acid) and lack of ATP causes the muscle to contract less
© 2012 Pearson Education, Inc.
ATP causes the muscle to contract less
![Page 71: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/71.jpg)
Types of Muscle Contractions
•Isotonic contractions•Myofilaments are able to slide past each other during contractionsg
•The muscle shortens and movement occursE l b di th k t ti th•Example: bending the knee; rotating the arm
•Isometric contractions•Tension in the muscles increasesTh l i bl t h t d•The muscle is unable to shorten or produce movement
© 2012 Pearson Education, Inc.
•Example: push against a wall with bent elbows
![Page 72: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/72.jpg)
Muscle Tone
•Some fibers are contracted even in a relaxed muscle
•Different fibers contract at different times toDifferent fibers contract at different times to provide muscle tone and to be constantly readyready
© 2012 Pearson Education, Inc.
![Page 73: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/73.jpg)
Effect of Exercise on Muscles
•Exercise increases muscle size, strength, and endurance•Aerobic (endurance) exercise (bikingAerobic (endurance) exercise (biking, jogging) results in stronger, more flexible muscles with greater resistance to fatiguemuscles with greater resistance to fatigue•Makes body metabolism more efficient•Improves digestion, coordination
•Resistance (isometric) exercise (weight•Resistance (isometric) exercise (weight lifting) increases muscle size and strength
© 2012 Pearson Education, Inc.
![Page 74: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/74.jpg)
© 2012 Pearson Education, Inc. Figure 6.11a-b
![Page 75: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/75.jpg)
Type I fibers Type II a fibers Type II x fibers Type II b fibers
Contraction time Slow Moderately Fast Fast Very fast
Size of motor neuron Small Medium Large Very large
Resistance to fatigue High Fairly high Intermediate Lowg g y g
Activity Used for Aerobic Long-term anaerobic Short-term anaerobic Short-term anaerobic
Maximum duration of use Hours <30 minutes <5 minutes <1 minuteuse
Power produced Low Medium High Very high
Mitochondrial density Very High High Medium Low
Capillary density High Intermediate Low Low
Oxidative capacity High High Intermediate Low
Glycolytic capacity Low High High HighGlycolytic capacity Low High High High
Major storage fuel Triglycerides Creatine phosphate, glycogen
ATP, Creatine phosphate, glycogen (little)
ATP, Creatine phosphate
Note Consume lactic acid Produce lactic acid and Creatine phosphate
Consume Creatine phosphate
Consume Creatine phosphate
Myosin heavy chain
© 2012 Pearson Education, Inc.
Myosin heavy chain,human genes MYH7 MYH2 MYH1 MYH4
![Page 76: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/76.jpg)
Five Golden Rules of Skeletal Muscle Activity1 With a few exceptions all skeletal muscles1. With a few exceptions, all skeletal muscles
cross at least one joint.2 T i ll th b lk f k l t l l li2. Typically, the bulk of a skeletal muscle lies
proximal to the joint crossed.3. All skeletal muscles have at least two
attachments: the origin and the insertion.attachments: the origin and the insertion.4. Skeletal muscles can only pull; they never
pushpush.5. During contraction, a skeletal muscle
© 2012 Pearson Education, Inc.
insertion moves toward the origin.
![Page 77: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/77.jpg)
Muscles and Body Movements
•Movement is attained due to a muscle moving an attached bone
•Muscles are attached to at least two pointsMuscles are attached to at least two points•Origin
•Attachment to a moveable bone•InsertionInsertion
•Attachment to an immovable bone
© 2012 Pearson Education, Inc.
![Page 78: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/78.jpg)
Musclecontracting
Origin
Brachialis
Tendon
© 2012 Pearson Education, Inc. Figure 6.12
Insertion
![Page 79: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/79.jpg)
© 2012 Pearson Education, Inc.
![Page 80: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/80.jpg)
Types of Body Movements
•FlexionD th l f th j i t•Decreases the angle of the joint
•Brings two bones closer togetherg g•Typical of bending hinge joints like knee and elbow or ball and socket joints like the hipelbow or ball-and-socket joints like the hip
•Extension•Opposite of flexion•Increases angle between two bones•Increases angle between two bones•Typical of straightening the elbow or knee
© 2012 Pearson Education, Inc.
•Extension beyond 180° is hypertension
![Page 81: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/81.jpg)
© 2012 Pearson Education, Inc. Figure 6.13a
![Page 82: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/82.jpg)
© 2012 Pearson Education, Inc. Figure 6.13b
![Page 83: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/83.jpg)
Types of Body Movements
•Rotation•Movement of a bone around its longitudinal axisaxis
•Common in ball-and-socket joints•Example is when you move atlas around the dens of axis (shake your head “no”)( y )
© 2012 Pearson Education, Inc.
![Page 84: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/84.jpg)
© 2012 Pearson Education, Inc. Figure 6.13c
![Page 85: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/85.jpg)
Types of Body Movements
•Abduction•Movement of a limb away from the midline
Adduction•Adduction•Opposite of abduction•Movement of a limb toward the midline
© 2012 Pearson Education, Inc.
![Page 86: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/86.jpg)
© 2012 Pearson Education, Inc. Figure 6.13d
![Page 87: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/87.jpg)
Types of Body Movements
•Circumduction•Combination of flexion, extension, abduction, and adductionand adduction
•Common in ball-and-socket joints
© 2012 Pearson Education, Inc.
![Page 88: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/88.jpg)
© 2012 Pearson Education, Inc. Figure 6.13d
![Page 89: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/89.jpg)
Special Movements
•Dorsiflexion•Lifting the foot so that the superior surface approaches the shin (toward the dorsum)approaches the shin (toward the dorsum)
•Plantar flexion•Depressing the foot (pointing the toes)•“Planting” the foot toward the solePlanting the foot toward the sole
© 2012 Pearson Education, Inc.
![Page 90: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/90.jpg)
© 2012 Pearson Education, Inc. Figure 6.13e
![Page 91: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/91.jpg)
Special Movements
•Inversion•Turn sole of foot medially
Eversion•Eversion•Turn sole of foot laterally
© 2012 Pearson Education, Inc.
![Page 92: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/92.jpg)
© 2012 Pearson Education, Inc. Figure 6.13f
![Page 93: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/93.jpg)
Special Movements
•Supination•Forearm rotates laterally so palm faces anteriorlyanteriorly
•Radius and ulna are parallel•Pronation
•Forearm rotates medially so palm facesForearm rotates medially so palm faces posteriorly R di d l h th lik X•Radius and ulna cross each other like an X
© 2012 Pearson Education, Inc.
![Page 94: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/94.jpg)
© 2012 Pearson Education, Inc. Figure 6.13g
![Page 95: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/95.jpg)
Special Movements
•Opposition•Move thumb to touch the tips of other fingers on the same handfingers on the same hand
© 2012 Pearson Education, Inc.
![Page 96: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/96.jpg)
© 2012 Pearson Education, Inc. Figure 6.13h
![Page 97: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/97.jpg)
Types of Muscles
•Prime mover—muscle with the major responsibility for a certain movement
•Antagonist—muscle that opposes or reversesAntagonist muscle that opposes or reverses a prime moverS i t l th t id i i•Synergist—muscle that aids a prime mover in a movement and helps prevent rotation
•Fixator—stabilizes the origin of a prime mover
© 2012 Pearson Education, Inc.
![Page 98: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/98.jpg)
(a) A muscle that crosses on the anterior side of a joint produces flexion*
Example:PectoralisPectoralis major(anterior view)
© 2012 Pearson Education, Inc. Figure 6.14a
![Page 99: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/99.jpg)
(b) A muscle that crosses on the posterior side of a joint produces extension*
Example:Latissimusd idorsi(posteriorview)
© 2012 Pearson Education, Inc. Figure 6.14b
![Page 100: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/100.jpg)
(c) A muscle that crosses on the lateral side of a joint produces abduction
Example:Medial deltoid(anterolateralview)
© 2012 Pearson Education, Inc. Figure 6.14c
![Page 101: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/101.jpg)
(d) A muscle that crosses on the medial side of a joint produces adduction
E lExample:Teres major(posterolateralview)
© 2012 Pearson Education, Inc. Figure 6.14d
![Page 102: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/102.jpg)
Naming Skeletal Muscles
•By direction of muscle fibers•Example: Rectus (straight)
By relative size of the muscle•By relative size of the muscle•Example: Maximus (largest)
© 2012 Pearson Education, Inc.
![Page 103: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/103.jpg)
Naming Skeletal Muscles
•By location of the muscle•Example: Temporalis (temporal bone)
By number of origins•By number of origins•Example: Triceps (three heads)
© 2012 Pearson Education, Inc.
![Page 104: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/104.jpg)
Naming Skeletal Muscles
•By location of the muscle’s origin and insertion•Example: Sterno (on the sternum)
By shape of the muscle•By shape of the muscle•Example: Deltoid (triangular)
•By action of the muscleExample: Flexor and extensor (flexes or•Example: Flexor and extensor (flexes or extends a bone)
© 2012 Pearson Education, Inc.
![Page 105: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/105.jpg)
© 2012 Pearson Education, Inc.
![Page 106: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/106.jpg)
Orbicularis orisDeltoidPectoralis major
(d) Circular
(a) Convergent
Biceps brachii (d)(e) Multipennate
Rectus femoris
(a)(e)
(b)
Rectus femoris
(f) Bipennate(c)
(b) Fusiform (f) Bipennate( )
Sartorius (f) Extensor digitorum longus
(g)
© 2012 Pearson Education, Inc. Figure 6.15(g) Unipennate(c) Parallel
![Page 107: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/107.jpg)
Head and Neck Muscles•Facial muscles
•Frontalis raises eyebrows•Frontalis—raises eyebrows•Orbicularis oculi—closes eyes, squints, blinks winksblinks, winks
•Orbicularis oris—closes mouth and protrudes the lipsp ot udes t e ps
•Buccinator—flattens the cheek, chews•Zygomaticus—raises corners of the mouthZygomaticus raises corners of the mouth
•Chewing muscles•Masseter closes the jaw and elevates•Masseter—closes the jaw and elevates mandible
•Temporalis—synergist of the masseter
© 2012 Pearson Education, Inc.
Temporalis synergist of the masseter, closes jaw
![Page 108: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/108.jpg)
Head and Neck Muscles
•Neck muscles•Platysma—pulls the corners of the mouth inferiorlyinferiorly
•Sternocleidomastoid—flexes the neck, t t th h drotates the head
© 2012 Pearson Education, Inc.
![Page 109: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/109.jpg)
CranialaponeurosisFrontalis
Orbicularisoculi
Temporalis
Occipitalisoculi
Zygomaticus
Occipitalis
O bi l i
BuccinatorMasseter
Orbicularisoris Sternocleidomastoid
PlatysmaTrapezius
© 2012 Pearson Education, Inc. Figure 6.16
![Page 110: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/110.jpg)
Muscles of Trunk, Shoulder, Arm
•Anterior muscles•Pectoralis major—adducts and flexes the humerushumerus
•Intercostal muscles •External intercostals—raise rib cage during inhalationg
•Internal intercostals—depress the rib cage to move air out of the lungs when youto move air out of the lungs when you exhale forcibly
© 2012 Pearson Education, Inc.
![Page 111: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/111.jpg)
Clavicle
Deltoid
Sternum
Pectoralismajor
Bicepsbrachii
Brachialis
Brachio-di liradialis
© 2012 Pearson Education, Inc. Figure 6.17a(a)
![Page 112: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/112.jpg)
Muscles of Trunk, Shoulder, Arm
•Muscles of the abdominal girdle•Rectus abdominis—flexes vertebral column and compresses abdominal contentsand compresses abdominal contents (defecation, childbirth, forced breathing)E t l bli fl t b l l•External oblique—flex vertebral column; rotate trunk and bend it laterally
•Internal oblique—flex vertebral column; rotate trunk and bend it laterallyrotate trunk and bend it laterally
•Transversus abdominis—compresses abdominal contents
© 2012 Pearson Education, Inc.
abdominal contents
![Page 113: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/113.jpg)
Pectoralismajormajor
RectusabdominisTransversusabdominisInternaloblique
ExternalExternalobliqueAponeurosisp
© 2012 Pearson Education, Inc. Figure 6.17b(b)
![Page 114: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/114.jpg)
Muscles of Trunk, Shoulder, Arm
•Posterior muscles•Trapezius—elevates, depresses, adducts, and stabilizes the scapulaand stabilizes the scapula
•Latissimus dorsi—extends and adducts the hhumerus
•Erector spinae—back extensionp•Quadratus lumborum—flexes the spine laterallylaterally
•Deltoid—arm abduction
© 2012 Pearson Education, Inc.
![Page 115: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/115.jpg)
Muscles of Trunk, Shoulder, Arm
•Muscles that arise from the shoulder girdle and cross the shoulder joint to insert into the humerus include:•Pectoralis majorL ti i d i•Latissimus dorsi
•Deltoid
PLAY A&P Flix™: Muscles of the pectoral girdle
PLAY A&P Flix™: Muscles that act on the shoulder joint and humerus: An overview.
PLAY A&P Flix™: Muscles that cross the glenohumeral joint.
PLAY A&P Flix™: Muscles of the pectoral girdle.
© 2012 Pearson Education, Inc.
PLAY A&P Flix™: Movement at the glenohumeral joint: An overview.
![Page 116: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/116.jpg)
Occipital bone
Sternocleidomastoid
Trapezius Spine of scapulaDeltoid (cut)
Deltoid
TricepsbrachiibrachiiLatissimusdorsi
Olecranonprocess of
Humerus
© 2012 Pearson Education, Inc. Figure 6.18a
process ofulna (deepto tendon)
(a)
![Page 117: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/117.jpg)
C7T1
Erector spinaep• Iliocostalis• Longissimus• Spinalis
QuadratusIumborum
© 2012 Pearson Education, Inc. Figure 6.18b(b)
![Page 118: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/118.jpg)
Muscles of the Upper Limb
•Biceps brachii—supinates forearm, flexes elbow
•Brachialis—elbow flexionBrachialis elbow flexion•Brachioradialis—weak muscle; elbow flexion•Triceps brachii—elbow extension (antagonist to biceps brachii)p )
PLAY A&P Flix™: The elbow joint and forearm: An overview.
&
PLAY A&P Flix™: Muscles of the elbow joint.
© 2012 Pearson Education, Inc.
PLAY A&P Flix™: Movement at the elbow joint.
![Page 119: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/119.jpg)
Clavicle
Deltoid
Sternum
Pectoralismajor
Bicepsbrachii
Brachialis
Brachio-di liradialis
© 2012 Pearson Education, Inc. Figure 6.17a(a)
![Page 120: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/120.jpg)
Occipital bone
Sternocleidomastoid
Trapezius Spine of scapulaDeltoid (cut)
Deltoid
TricepsbrachiibrachiiLatissimusdorsi
Olecranonprocess of
Humerus
© 2012 Pearson Education, Inc. Figure 6.18a
process ofulna (deepto tendon)
(a)
![Page 121: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/121.jpg)
Muscles of the Upper Limb
•Muscles of the forearm, which insert on the h d b d th i thand bones and cause their movement include:
•Flexor carpi—wrist flexion•Flexor digitorum—finger flexion•Flexor digitorum—finger flexion•Extensor carpi—wrist extension•Extensor digitorum—finger extension
PLAY A&P Flix™: Muscles that act on the wrist and fingers:
PLAY A&P Flix™: Movements of the wrist and fingers (a).
PLAY A&P Flix : Muscles that act on the wrist and fingers: An overview.
© 2012 Pearson Education, Inc.
PLAY A&P Flix™: Movements of the wrist and fingers (b).
![Page 122: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/122.jpg)
Muscles of the Lower Limb
•Muscles causing movement at the hip joint include:•Gluteus maximus—hip extensionGluteus maximus hip extension•Gluteus medius—hip abduction, steadies
l i h lkipelvis when walking•Iliopsoas—hip flexion, keeps the upper body p p , p pp yfrom falling backward when standing erect
•Adductor muscles adduct the thighs•Adductor muscles—adduct the thighsPLAY A&P Flix™: Muscles that act on the hip joint and femur:
An overview
© 2012 Pearson Education, Inc.
PLAY A&P Flix™: Movement at the hip joint: An overview.An overview.
![Page 123: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/123.jpg)
Gluteus medius
Gluteus maximus
Adductormagnus
Iliotibial tract
Biceps femoris
SemitendinosusSemimembranosus
Hamstring group
© 2012 Pearson Education, Inc. Figure 6.20a
Gastrocnemius
(a)
![Page 124: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/124.jpg)
Posterior superioriliac spine
IIiac crest
p
Safe area inSafe area ingluteus medius
S i ti
Gluteus maximus
Sciatic nerve
© 2012 Pearson Education, Inc. Figure 6.20b(b)
![Page 125: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/125.jpg)
12th rib12ththoracic vertebra
Iliac crestlliopsoas Psoas major
lliacus
Anterior superiorili i
5thlumbar vertebra
iliac spine
SartoriusAdd t
Rectus femoris
Vastus lateralis
ricep
s
Adductorgroup
Vastus medialisQua
dr
Patellarligament
Patella
© 2012 Pearson Education, Inc. Figure 6.20c
g
(c)
![Page 126: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/126.jpg)
Muscles of the Lower Limb
•Muscles causing movement at the knee joint•Hamstring group—thigh extension and knee flexionflexion•Biceps femoris•Semimembranosus•SemitendinosusSemitendinosus
© 2012 Pearson Education, Inc.
![Page 127: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/127.jpg)
Gluteus medius
Gluteus maximus
Adductormagnus
Iliotibial tract
Biceps femoris
SemitendinosusSemimembranosus
Hamstring group
© 2012 Pearson Education, Inc. Figure 6.20a
Gastrocnemius
(a)
![Page 128: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/128.jpg)
Muscles of the Lower Limb
•Muscles causing movement at the knee joint•Sartorius—flexes the thighQuadriceps group extends the knee•Quadriceps group—extends the knee•Rectus femoris•Vastus muscles (three)
PLAY A&P Flix™: Muscles that cross the knee joint: An overview.
© 2012 Pearson Education, Inc.
![Page 129: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/129.jpg)
12th rib12ththoracic vertebra
Iliac crestlliopsoas Psoas major
lliacus
Anterior superiorili i
5thlumbar vertebra
iliac spine
SartoriusAdd t
Rectus femoris
Vastus lateralis
ricep
s
Adductorgroup
Vastus medialisQua
dr
Patellarligament
Patella
© 2012 Pearson Education, Inc. Figure 6.20c
g
(c)
![Page 130: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/130.jpg)
Inguinal
Add t
Inguinalligament
Sartorius
Adductormuscles
Vastus
Sartorius
lateralis
© 2012 Pearson Education, Inc. Figure 6.20d(d)
![Page 131: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/131.jpg)
Muscles of the Lower Limb
•Muscles causing movement at ankle and footTibi li t i d ifl i f t i i•Tibialis anterior—dorsiflexion, foot inversion
•Extensor digitorum longus—toe extension g gand dorsiflexion of the foot
•Fibularis muscles plantar flexion foot•Fibularis muscles—plantar flexion, foot eversion
•Soleus—plantar flexionPLAY A&P Flix™: Muscles that act on the ankle and foot:
PLAY A&P Flix™: Posterior muscles that act on the ankle and foot.An overview.
© 2012 Pearson Education, Inc.
PLAY A&P Flix™: Movements of the ankle and foot.
![Page 132: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/132.jpg)
Fibularis longus
Tibia
Tibialis anteriorExtensor digitorumlongus
TibiaSoleus
Fibularis brevis
Fibularis tertius
longus
© 2012 Pearson Education, Inc. Figure 6.21a(a)
![Page 133: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/133.jpg)
Gastrocnemius
Soleus
Calcaneal (Achilles)tendontendon
Medial malleolusLateralmalleolus
© 2012 Pearson Education, Inc. Figure 6.21b(b)
![Page 134: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/134.jpg)
Facial• Temporalis
Facial• Frontalis• Orbicularis oculi• Zygomaticus
• Masseter
Shoulder• Trapezius
• Deltoid
• Orbicularis orisNeck• Platysma• SternocleidomastoidThorax• Pectoralis minor
Arm• Triceps brachii• Biceps brachii• Brachialis
• Pectoralis major• Serratus anterior
• Intercostals
Abdomen• Rectus abdominis
Forearm• Brachioradialis• Flexor carpi radialis
Pelvis/thigh• lliopsoas
• External oblique• Internal oblique• Transversus abdominis
Thigh (Quadriceps)• Rectus femoris• Vastus lateralis
Thigh• Sartorius• Adductor muscle
• Gracilis
• Vastus medialis
Leg• Fibularis longus
Leg• Extensor digitorum longus
• Tibialis anterior
Leg• Gastrocnemius
• Soleus
© 2012 Pearson Education, Inc. Figure 6.22
![Page 135: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/135.jpg)
Neck• Occipitalis
Arm
• Sternocleidomastoid
• Trapezius
Shoulder/Back• DeltoidArm
• Triceps brachii• BrachialisForearm• Brachioradialis• Extensor carpi radialis
longus
• Latissimus dorsi
longus• Flexor carpi ulnaris• Extensor carpi ulnaris• Extensor digitorum
Hip• Gluteus medius
• Gluteus maximus
lliotibial tract Thigh• Adductor muscle• Hamstrings:
Leg
gBiceps femorisSemitendinosusSemimembranosus
• Gastrocnemius
• Soleus
• Fibularis longus
© 2012 Pearson Education, Inc. Figure 6.23
Calcaneal(Achilles)tendon
![Page 136: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/136.jpg)
D lt idDeltoidmuscle
Humerus
© 2012 Pearson Education, Inc. Figure 6.19
![Page 137: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/137.jpg)
Posterior superioriliac spine
IIiac crest
p
Safe area inSafe area ingluteus medius
S i ti
Gluteus maximus
Sciatic nerve
© 2012 Pearson Education, Inc. Figure 6.20b(b)
![Page 138: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/138.jpg)
Inguinal
Add t
Inguinalligament
Sartorius
Adductormuscles
Vastus
Sartorius
lateralis
© 2012 Pearson Education, Inc. Figure 6.20d(d)
![Page 139: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/139.jpg)
Superficial Anterior Muscles of the Body
© 2012 Pearson Education, Inc.
Table 6.3 (1 of 3)
![Page 140: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/140.jpg)
Superficial Anterior Muscles of the Body
© 2012 Pearson Education, Inc.
Table 6.3 (2 of 3)
![Page 141: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/141.jpg)
Superficial Anterior Muscles of the Body
© 2012 Pearson Education, Inc.
Table 6.3 (3 of 3)
![Page 142: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/142.jpg)
Superficial Posterior Muscles of the Body
© 2012 Pearson Education, Inc.
Table 6.4 (1 of 3)
![Page 143: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/143.jpg)
Superficial Posterior Muscles of the Body
© 2012 Pearson Education, Inc.
Table 6.4 (2 of 3)
![Page 144: The Muscular System - contents.kocw.or.krcontents.kocw.or.kr/document/wcu/2012/Anatomy_and_Physiology/0… · Characteristics of Muscles •Skeletal and smooth muscle cells are elongated](https://reader036.vdocuments.site/reader036/viewer/2022062919/5ee0275bad6a402d666b649c/html5/thumbnails/144.jpg)
Superficial Posterior Muscles of the Body
© 2012 Pearson Education, Inc.
Table 6.4 (3 of 3)