copyright © 2010 pearson education, inc. skeletal muscles: functional groups 1.agonist = prime...

Copyright © 2010 Pearson Education, Inc.

Skeletal Muscles: Functional Groups

1. Agonist = Prime mover - Provides the major force for producing a specific movement

2. Antagonist - Opposes or reverses a particular movement

3. Synergist – Works together with a prime mover to add force or control

4. Fixator – Synergist that immobilizes a bone that is a muscle’s origin


Naming Skeletal Muscles

• Location of attachments—named according to the bones to which they attach

• Location—bone or body region close to the muscle

• Action—e.g., flexor or extensor, muscles that flex or extend, respectively


Naming Skeletal Muscles

• Shape—e.g., deltoid muscle (deltoid = triangle)

• Relative size—e.g., maximus (largest), minimus (smallest), longus (long)

• Number of origins—e.g., biceps (2 origins) and triceps (3 origins)

• Direction of fibers or fascicles—e.g., rectus (fibers run straight), transversus, and oblique (fibers run at angles to an defined axis)


Figure 10.1 Patterns of fascicle arrangement in muscles.

(a)

(b)

(e)

(d)

(g)

(f)

(c)

(a)Circular (orbicularis oris)

(b) Convergent (pectoralis major)

(c) Parallel (sartorius)

(d) Unipennate (extensor digitorum longus)

(f) Fusiform (biceps brachii)

(g) Multipennate (deltoid)

(e) Bipennate (rectus femoris)


Figure 6.2 Major skeletal muscle groups and their functions. (1 of 2)


Figure 6.2 Major skeletal muscle groups and their functions. (2 of 2)


Figure 10.5 Posterior view of superficial muscles of the body.

Arm

Forearm

Leg

HipGluteus mediusGluteus maximus

Thigh


Figure 10.6 Lateral view of muscles of the scalp, face, and neck.

Orbicularis oculi

Zygomaticusminor and majorBuccinator

Orbicularis oris

Platysma

Frontal belly

Occipitalbelly

Temporalis

MasseterSternocleidomastoidTrapezius

Epicranius

Aponeurosis


Figure 10.8a Muscles of the anterior neck and throat that promote swallowing.

AnteriorbellyPosteriorbelly

Hyoid bone

Sternocleido-mastoid

Digastric

Thyroid gland

(a)


Figure 10.9a Muscles of the neck and vertebral column causing movements of the head and trunk.

1st cervicalvertebra


(a) Anterior

Base ofoccipital bone

Middlescalene

AnteriorscalenePosteriorscalene

Mastoidprocess


Figure 10.10a Muscles of respiration.

Externalintercostal

(a) Internalintercostal


Figure 10.10b Muscles of respiration.

Foramen foresophagusCostal cartilage

Lumbarvertebra

Xiphoid process of sternum

Diaphragm

Psoas major

Foramen for inferiorvena cava

Centraltendon ofdiaphragm

Foramenfor aorta

12th rib

(b)


Figure 10.11a Muscles of the abdominal wall.

Transversus abdominis

Internal oblique

External oblique

(a)

Pectoralis major

Rectusabdominis

Serratus anterior

aponeurosis


Figure 10.11b Muscles of the abdominal wall.

Transversusabdominis

Lumbarfascia

Lumbarfascia

Internaloblique

Pubictubercle

Rectusabdominis

Externaloblique

(b)

IIiac crest


Figure 10.13a Superficial muscles of the thorax and shoulder acting on the scapula and arm.

Clavicle

Serratus anterior

Humerus


DeltoidPectoralismajor Sternum

Biceps brachii

(a)


Figure 10.13c Superficial muscles of the thorax and shoulder acting on the scapula and arm.

Trapezius

(c)

Clavicle

Spine ofscapula

Humerus

Deltoid

Latissimusdorsi


Figure 10.14b Muscles crossing the shoulder and elbow joint, causing movements of the arm and forearm, respectively.

Spine of scapula

(b) Posterior view

Deltoid (cut)Greater tubercleof humerus

Triceps brachii:

Latissimus dorsi

HumerusOlecranon processof ulna

Lateral head Long head


Figure 10.14c Muscles crossing the shoulder and elbow joint, causing movements of the arm and forearm, respectively.

Long headBicepsbrachii Short head

O = origin I = insertion

(c)


Figure 10.15a Muscles of the anterior fascial compartment of the forearm acting on the right wrist and fingers.

Extensor c.. r... l..

Flexor p.. l..

Medial epicondyleof humerus

Flexor c.. r..

Flexor c.. u..

Flexor digitorum s..

(a)


Flexor c.. u..

Extensor c.. u..

Extensor d.. m.. Extensor i..

(a)

Extensor p.. l..

Extensor p.. b..

Extensor digitorum

Extensor c.. r.. b..

Extensor c.. r.. l..

Figure 10.16a Muscles of the posterior fascial compartment of the right forearm acting on the wrist and fingers.


Figure 10.17a Summary of actions of muscles of the arm and forearm.

Tricepsbrachii

Lateralhead

Humerus

LongheadMedialhead

(a)

{Brachialis}

Short headLong head

(a) Muscles of the arm

Extensors

Flexors

Others

Posteriorcompartment

of arm (extendselbow)

Biceps brachii

Anterior compartment of arm (flexes elbow)


Figure 10.17b Summary of actions of muscles of the arm and forearm.

Extensors

Flexors

Others

(b)

Flexors

Extensors

Ulna

Posterior compartment of forearm(extends wrist and fingers)

Others

Radius

(b) Muscles of the forearm

Anterior compartment of forearm (flexes wrist and fingers)


Figure 10.19a Anterior and medial muscles promoting movements of the thigh and leg.

Iliac crestPsoas major

Iliopsoas

12th rib

Iliacus

Anterior superior iliac spine

Sartorius

Quadriceps femoris• Rectus femoris

• Vastus lateralis• Vastus medialis

(a)

Patella

12th thoracic vertebra

5th lumbar vertebra

Adductor longus


Figure 10.19b Anterior and medial muscles promoting movements of the thigh and leg.

(b)


Adductorlongus

Femur


Figure 10.19c Anterior and medial muscles promoting movements of the thigh and leg.

VastuslateralisVastusintermediusVastusmedialis

(c)

PatellaPatellarligament

Rectus femoris(tendon cut)


muscles of Quadriceps group


Gluteus medius

Gluteus maximus

Long head

SemitendinosusSemimembranosus

Short headBicepsfemoris

Hamstrings

(a)

Figure 10.20a Posterior muscles of the right hip and thigh.


Tibialis anterior


(b)

Figure 10.21b Muscles of the anterior compartment of the right leg.


Patella

Head of fibula

GastrocnemiusSoleusFibularis longus

Tibialis anterior

Lateral malleolus

(a)

Figure 10.22a Muscles of the lateral compartment of the right leg.


Fibularislongus

Tendon of fibularis longus


(b)

Figure 10.22b Muscles of the lateral compartment of the right leg.


Figure 10.23a Muscles of the posterior compartment of the right leg.

Gastrocnemius Medial headLateral head

Tendon ofgastrocnemius

Calcaneal tendon(Achilles)

Calcaneus

(a) Superficial view of the posterior leg.


Figure 10.25a Summary of actions of muscles of the thigh and leg.

Posterior compartment ofthigh (flexes leg and extendsthigh)

Medial compartment (adductsthigh)

Anterior compartment (extends leg)

Vastusintermedius

Rectus femorisVastus medialis

(a) Muscles of the thigh

Posteriorcompartmentmuscles

Anteriorcompartmentmuscle

Medialcompartmentmuscles of thighand lateralcompartmentmuscles of leg

Adductors

Vastuslateralis

Hamstrings

Femur

(a)


Figure 10.25b Summary of actions of muscles of the thigh and leg.

Posterior compartmentof leg (plantar flexes foot,flexes toes)

Anterior compartment of leg(dorsiflexes foot, extends toes)

Lateral compartment of leg(plantar flexes and everts foot);innervation

Gastrocnemius and soleus

Fibula

Tibialisanterior Tibia

Fibularismuscles

(b) Muscles of the leg

(b)

Posteriorcompartmentmuscles

Anteriorcompartmentmuscle

Medialcompartmentmuscles of thighand lateralcompartmentmuscles of leg


Figure 15.3a Extrinsic eye muscles.

Inferior rectusmuscle

Inferior obliquemuscle

Superior obliquemuscle

Superior obliquetendon

Superior rectusmuscle

Lateral rectusmuscle

(a) Lateral view of the right eye


Figure 15.3b Extrinsic eye muscles.

Superior obliquemuscle

Trochlea

Superior obliquetendon

Superior rectusmuscle

(b) Superior view of the right eye

Medialrectus muscle

Inferiorrectus muscle

Lateralrectus muscle

copyright © 2010 pearson education, inc. skeletal muscles: functional groups 1.agonist = prime...

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