Energy source for contraction

• ATP • ADP + Creatine phosphate = ATP

• ATP is constantly broken down and rebuilt

• ATP = adenosine triphosphate• ADP= adenosine diphosphate

• ATP produced by cellular respiration– occurs in the mitochondria (requires O2 and

glucose)• 25% of energy formed is used• What happens to the rest?• Heat more muscle activity= more heat

Oxygen Debt

• Oxygen is used to make ATP in cellular Resp. • Exerciserun out of O₂ = Lactic acid

Fermentation • Lactic Acid Fermentation – muscle cramps

Muscle Fatigue

• Muscle lose ability to contract after prolonged exercise or strain

• Caused by lactic acid build up

Threshold Stimulus

• Minimal strength required to cause a contraction

• Motor neuron releases enough acetylcholine to reach threshold

All-or-None Response• Fibers do not contract partially, they either do

or don't

• Motor Unit • The muscle fiber + the motor neuron

• Recruitment• more and more fibers contract as the intensity of the stimulus

increases

• Muscle Tone• Sustained contraction of individual fibers, even when muscle is

at rest• Lost if motor nerve axons are cut

• Hypertrophy - muscles enlarge (working out or certain disorders)

• Atrophy - muscles become small and weak due to disuse

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1. Tendon2. Muscle3. Fasicle4. Muscle fiber5. Myofibril6. Endomysium7. Perimysium8. Epimysium

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1. Muscle2. Epimysium3. Fasicle4. Endomysium5. Sarcolemma6. Myfibirl7. perimysium

Major Skeletal muscles

• Names of muscles describe them• Ex: pectoralis major- large muscle in pectoral

region• Ex: Deltoid- shaped like a delta or triangle

Muscle of Facial Expression

• Enable communication of feelings• Epicranius – frontalis and occipitalis• Orbicularis oculi- around eye• Orbicularis oris- around mouth• Buccinator- cheek• Zygomaticus major- zygomatic arch• Zygomaticus minor- zygomatic arch• Platysma- chest upward over neck to face, frown

Muscle of Mastication

Chewing movements• Masseter• Temporalis• Medial pterygoid• Lateral Pterygoid

Move Head and Vertebral Column

• Sternocleidomastoid• Splenius capitis• Semispinalis capitis

Back• Trapezius• Deltoid• Rhomboid major• Rhomboid minor• Levator scapulae• Teres Major• Teres Minor• Infraspinatus• Supraspinatus• Latissimus dorsi• http://www.biologycorner.com/anatomy/muscles/back/back.swf

Front• Trapezius• Sternocleidomastoid• Deltoid• Pectoralis minor• Pectoralis major• Serratus anterior• Rectus abdominis• Internal oblique• External oblique• http://www.biologycorner.com/anatomy/muscles/torso/to

rso.swf

Arm• Subscapularis• Triceps brachii• Biceps Brachii• Brachialis• CoracobrachialisTop• Extensor carpi ulnaris• Extensor carpi radialis brevis• Extensor carpi radialis longus• Extensor digitorum• Flexor carpi ulanrishttp://www.biologycorner.com/anatomy/muscles/arms/top_arm.swf

Arm

Bottom/Underneath• Biceps brachii• Brachioradialis• Brachialis• Pronator teres• Flexor carpi radialis• Flexor carpi ulnaris• Palmaris longus• http://www.biologycorner.com/anatomy/muscles/ar

ms/bottom_arm.swf

Leg MusclesFront:• Sartorius• Rectus Femoris• Vastus lateralis• Vastus medialis• Gracilis• Tensor fasciae latae• Tibialis anterior• Fibularis longus• Extensor digitorum longus• http://www.biologycorner.com/anatomy/muscles/legs/front_legs

.swf

Leg Muscles

Back:• Gluteus maximus• Gluteus medius• Gracilis• Semimembranosus• Semitendinosus• Biceps femoris• Gastrocnemius• Soleus• http://www.biologycorner.com/anatomy/muscles/legs/bac

k_legs.swf