Module 5.3 - Physiology of the Muscular System

Question 1

Which type of muscles are under involuntary control?

Answer 1

smooth and cardiac muscle

Question 2

Voluntary muscle control

Answer 2

conscious decision made to move muscle

Question 3

Which types of muscles have striations?

Answer 3

cardiac and skeletal muscles

Question 4

What is the one motion muscles can make?

Answer 4

pulling by contracting

Question 5

flexion

Answer 5

closing of a close

Question 6

extension

Answer 6

opening of a joint

Question 7

antagonistic muscle pair

Answer 7

perform opposing muscle actions (e.i flexon/extension)

Question 8

abduction

Answer 8

movement away from midline

Question 9

adduction

Answer 9

movement toward midline

Question 10

dorsiflexion

Answer 10

flexion superiorly occurring at the subtalar (ankle) joint (movement of the toes “up”)

Question 11

plantarflexion

Answer 11

flexion inferiorly occurring at the subtalar (ankle) joint (movement of the toes “down”)

Question 12

radial deviation

Answer 12

lateral movement of wrist toward radius

Question 13

ulnar deviation

Answer 13

medial movement of wrist toward ulna

Question 14

pronation

Answer 14

rotation of forearm so palm faces posteriorly or rotation of ankle so sole of foot facing laterally

Question 15

supination

Answer 15

rotation of forearm so palm faces anteriorly, or rotation of ankle so sole of foot faces medially

Question 16

elevation

Answer 16

upward movement of structure

Question 17

depression

Answer 17

downward movement of structure

Question 18

retraction

Answer 18

movement of structure to be drawn in posterior direction (backward)

Question 19

proctraction

Answer 19

movement of structure to be drawn in anterior direction (forward)

Question 20

muscle fiber

Answer 20

cell containing thousands of myofibrils

Question 21

myofibrils

Answer 21

contractile portions of the fibers, cylindrical in shape, run length of muscle fiber

Question 22

striations

Answer 22

the light and dark bands of myofibrils formed by sacromeres

Question 23

sarcomere

Answer 23

contractile unit formed from by protein myofilaments

Question 24

What are the 2 types od protein myofilaments?

Answer 24

myosin and actin

Question 25

Myosin

Answer 25

thick filaments of proteins in sarcomeres

Question 26

Actin

Answer 26

thin filaments of protein in sarcomere

Question 27

How do sarcomere shorten?

Answer 27

actin filaments slide along myosin towards each other

Question 28

How is 1 sarcomere viewed/ measured under microscope?

Answer 28

Z-line to Z- line

Question 29

Z lines

Answer 29

connect the parallel bands of thin filaments

Question 30

M lines

Answer 30

hold together parallel thick filaments

Question 31

I band

Answer 31

appears light when stained because it contains only thin filaments

Question 32

A band

Answer 32

stains darker under microscope because it has both thin and thick filaments

Question 33

What do the lines of sarcomere do when muscles contract?

Answer 33

Z lines move closer together toward the M line

Question 34

What happens at neuromuscular junction?

Answer 34

a nerve impulse reaches the muscle fiber and acetylcholine is released from the nerve ending and binds onto the muscle cell

Question 35

What does ACH binding to muscle cell do and then trigger?

Answer 35

causes sodium channels to open allowing sodium to flow inside sacroplasm which triggers and action potential in sacrolemma

Question 36

sarcoplasm

Answer 36

cytoplasm of a muscle cell

Question 37

sacrolemma

Answer 37

cell membrane of muscle fiber

Question 38

sacroplasmic reticulum

Answer 38

a specialized smoother ER found in striated muscle tissue

Question 39

What is caused by the action potential of the sacrolemma?

Answer 39

calcium ions are released from the sacroplasmic reticulum which triggers the cross-bridges of myosin to rapily attach and reattach to actin filament pulling them along

Question 40

What is needed on a cellular level for myosin cross-bridges to pull the actin filaments?

Answer 40

ATP

Question 41

What happens when muscle contraction ceases?

Answer 41

nerve impulses no longer stimulate the muscle fiber, muscle action potential stops, and calcium ions are pumped back into the sarcoplasmic reticulum by active transport.