A. Muscle Anatomy And Physiology

Question 1

Abdominals

Answer 1

Rectus Abdominis
External Oblique
Internal Oblique
Transverse Abdominis

Question 2

Arms

Answer 2

• Biceps Brachii
• Brachialis
• Brachioradialis
• Triceps Brachii
• Finger Flexors
• Finger Extensors

Question 3

Back

Answer 3

• Latissimus Dorsi

- Trapezius

Question 4

Chest

Answer 4

• Pectoralis Major

Question 5

Anterior Legs

Answer 5

• Adductor Longus
• Gracilis
• Sartorius
• Rectus Femoris
• Vastus Lateralis
• Vastus Medialis
• Tibialis Anterior

Question 6

Posterior Legs

Answer 6

• Gluteus Maximus
• Semitendonosus
• Semimenbranosus
• Biceps Femoris
• Gastrocnemius
• Soleus

Question 7

Shoulders

Answer 7

• Deltoids
• Infraspinatus (rotator cuff)
• Teres Major (rotator cuff)

Question 8

Muscle Fiber

Answer 8

• long, cylindrical cells about 50 to 100 micrometers in diameter with a striated appearance

Question 9

Epimysium

Answer 9

• Connective tissue that covers every muscle (very fibrous)

Question 10

Muscle Tendon

Answer 10

• Part of the muscle that attaches to the bone (proximal attachment and distal attachment)

Question 11

Periosteum

Answer 11

Most outer layer of the bone (vascular connective tissue)

-however, not at surface of joints

Question 12

Perimysium

Answer 12

• layer that surrounds each fascicle

Question 13

Fascicle

Answer 13

• A group of muscle fibers

Question 14

Endomysium

Answer 14

• Layer that surrounds each individual muscle fiber

Question 15

Sarcolemma

Answer 15

• The muscle fiber membrane that contains a nucleus and a sarcoplasm

Question 16

Myofibril

Answer 16

• Located in the sarcoplasm and contains actin and myosin apparatus

Question 17

Order of Layers of the Skeletal Muscle (large to small)

Answer 17

• Muscle Belly –> Epimysium –> Perimysium –> Fascicle –> Sarcolemma –> Single Muscle Fiber –> Sarcoplasm –> Myofibril –> Myofilaments (actin/myosin)

Question 18

Myosin

Answer 18

• Thick Filaments with globular head, hinge point, and fibrous tail

Question 19

Cross Bridge

Answer 19

• A pair of myosin filaments that interacts with actin

Question 20

Sarcomere

Answer 20

• Smallest contractile unit of skeletal muscle that contain the cross bridge with the actin

Question 21

Sarcoplasmic Reticulum

Answer 21

• intricate system of tubules parallel to the myofibrils and terminates the z-lines

Question 22

Calcium Ions

Answer 22

• stored in the sarcoplasmic reticulum and are regulated to control muscle contraction

Question 23

T-Tubules

Answer 23

• run perpendicular to sarcoplasmic reticulum and and terminate around the z-lines (run between each myofibril)
• help to deliver an action potential simultaneously throughout the fibers (calcium released to produce coordinated contraction)

Question 24

Sliding Filament Theory

Answer 24

• actin filaments at each end of sarcomere slide inward on myosin filaments pulling the z-line toward the center of the sarcomere, therefore shortening the muscle fiber (for contraction)
• H zone shrinks, I-Band shrinks, Myosin pulls on Actin to move it
• very rapid and repeated flexions must occur in many crossbridges throughout each muscle for a measurable muscle movement to occur

Question 25

Concentric Muscle Action

Answer 25

• Muscle shortens because of the contractile force is GREATER than resistance

Question 26

Eccentric Muscle Action

Answer 26

• Muscle lengthens because contractile force is LESS than the resistance

Question 27

Isometric Muscle Action

Answer 27

• Muscle length does not change because contractile force EQUALS resistance force