Muscle Physiology

Question 1

Which nervous system is responsible for muscle contractions?

Answer 1

Peripheral efferent nervous system -> motor (somatic) nervous system pathway

Question 2

Skeletal muscle

Answer 2

muscle attached to bone

Question 3

ATP

Answer 3

Glucose and oxygen help produce, needed for muscle contraction

Question 4

Creatine phosphate

Answer 4

converts ADP back to ATP for more muscle contractions

Question 5

Aerobic

Answer 5

needs oxygen

Question 6

Anaerobic

Answer 6

doesn’t need oxygen

Question 7

Glucose metabolism steps (3)

Answer 7

1) breakdown of large macromolecules into simple substrates (proteins -> amino acids)
2) breakdown of simple substates into Acetyl CoA, production of limited amount of ATP and NADH
3) complete oxidation of Acetyl Coa to water and CO2, large production of NADH and ATP in mitochondria

Question 8

Slow-twitch oxidative red muscle

Answer 8

motor unit type 1, smallest in diameter. Posture. oxidative

Question 9

Oxidative

Answer 9

aerobic metabolism

Question 10

myoglobin

Answer 10

oxygen binding protein in muscle, gives dark red appearance

Question 11

fast-twitch oxidative red muscle

Answer 11

motor unit type 2A, standing and walking. Glycolytic

Question 12

glycolytic

Answer 12

anaerobic metabolism, more oxidative with endurance training

Question 13

fast-twitch glycolytic white muscle

Answer 13

motor unit type 2B, jumping/sprinting movements. short durations with lots of force. large diameter, glycolytic, pale color

Question 14

Do oxidative or glycolytic muscle fatigue faster

Answer 14

Glycolytic. produce lactic acid when glycogen supply runs out (burning sensation, slows down activity)

Question 15

Fascia

Answer 15

connective tissue layers outside of the muscle

Question 16

3 Types of fascia

Answer 16

epimysium, perimysium, endomysium

Question 17

Muscle fibers

Answer 17

skeletal muscle cells

Question 18

sarcolemma

Answer 18

muscle fiber cell membrane (like a plasma membrane)

Question 19

T-tublues

Answer 19

indentations in the sarcolemma

Question 20

sarcoplasm

Answer 20

muscle fiber cytoplasm, houses SR

Question 21

sarcoplasmic reticulum

Answer 21

inside the sarcoplasm, calcium storage compartment needed for muscle contraction

Question 22

motor units

Answer 22

muscle fiber and all motor neurons that innervate it

Question 23

myofibril

Answer 23

inside muscle fiber

Question 24

sarcomeres

Answer 24

inside myofibrils, lined end to end. basic contracting unit of the muscle

Question 25

actin and myosin

Answer 25

proteins in the sarcomere.

Question 26

accessory proteins in sarcomere

Answer 26

troponin and tropomyosin. help with contraction and relaxation

Question 27

Thick myosin filaments (A bands)

Answer 27

heads for attachment to actin

Question 28

thin actin filaments (I bands)

Answer 28

troponin and tropomyosin proteins, bind to calcium (SR) during contractions

Question 29

striated appearance due to. . .

Answer 29

light (thin) and dark (thick) bands of a sarcomere

Question 30

skeletal muscle contraction

Answer 30

actin and myosin forms cross bridges and myosin heads change shape, results in the pulling of thin actin filaments to the middle of the sarcomere