Muscle Contraction

Question 1

Muscle Fiber (myocyte/myofiber) Type I

Answer 1

slower contraction, more mitochondria, does not fatigue as fast

Question 2

Muscle Fiber (myocyte/myofiber) Type II

Answer 2

faster contraction, less mitochondria, fatigue quickly

Question 3

Titin

Answer 3

hold myosin in place and connect them to the Z disk

Question 4

Thick Filaments

Answer 4

Myosin [2 heavy chains, 2 light chains]

Question 5

Thin Filaments

Answer 5

Actin (F-actin monomers)

Question 6

Fascicle

Answer 6

group of myofibers surrounded by perimysium

Question 7

Muscle Fiber/Myofiber/Myocyte

Answer 7

made of myofibrils (chains of sarcomeres linked together) surrounded by endomysium

Question 8

Muscle

Answer 8

group of fascicles surrounded by epimysium

Question 9

Sarcomere

Answer 9

contractile unit of muscle made of actin and myosin

Question 10

What is enclosed by perimysium?

Answer 10

Fascicle: Group of myofibers

Question 11

What is enclosed by endomysium?

Answer 11

Muscle fibers: a group of myofibrils

Question 12

What is enclosed by epimysium?

Answer 12

Muscle: Group of fascicles

Question 13

I-Band

Answer 13

Part of sarcomere from Z-disk to end of Titin (or beginning of myosin)
Space of no myosin

Question 14

A Band

Answer 14

Length of myosin

Question 15

H band

Answer 15

space between actin fibers where there is no actin

Question 16

M line

Answer 16

attachment site for myosin (middle of sarcomere)

Question 17

Z Disk

Answer 17

Separates sarcomeres

Question 18

Transverse (T) Tubules

Answer 18

membrane system that conveys electrical impulses from the sarcolemma into the cell (electrical wiring)

Question 19

Sarcolemma

Answer 19

membrane around each muscle cell

Question 20

Terminal Cisternae

Answer 20

a flattened sac of SR on each side of transverse T tubule

Question 21

Tirad

Answer 21

T Tubule + 2 Terminal Cisternae

Question 22

End feet

Answer 22

Connect T tubules with SR to allow Calcium to be released

Question 23

Rule for muscle innervation

Answer 23

Muscle fibers are only innervated by a single nerve but a single nerve can innervate multiple fibers

Question 24

Neuromuscular Spindle Apparatus

Answer 24

System built into muscles to prevent over-stretching

Extrafusal and Intrafusal fibers

Question 25

Extrafusal fibers

Answer 25

Contract external muscle in response to Ia Fibers

Alpha motor neurons of anterior horn

Question 26

Intrafusal fibers

Answer 26

Sense rate and length of change inside muscle

Gamma motor neurons of anterior horn

Question 27

Type Ia Fibers

Answer 27

sense stretch and rate of change in intrafusal fibers

Sensory neurons of dorsal horn

Question 28

Multipolar neuron

Answer 28

multiple dendrites and one axon (typical neuron)

Question 29

Bipolar neuron

Answer 29

single dendrite (multiple extensions) and one axon

Question 30

Pseudounipolar

Answer 30

One cell process with a single dendrite and axon branch (cell body is not in line with rest of neuron)

Question 31

Myelin wraps what?

Answer 31

Single Axons