Spinal Cord and Muscles

Question 1

three types of muscle

Answer 1

skeletal, cardiac, smooth

Question 2

functional syncytium

Answer 2

a network where the cells work together with adjacent cells to undergo excitation

Question 3

whole muscle

Answer 3

organ

Question 4

fiber

Answer 4

muscle cells

Question 5

myofibrils

Answer 5

intracellular structure

Question 6

thick/thin filaments

Answer 6

cytoskeletal elements

Question 7

thin filamenets

Answer 7

actin

Question 8

thick filaments

Answer 8

myosin

Question 9

sarcomere

Answer 9

smallest functional unit of muscle cells

Question 10

Z line

Answer 10

the place where actin molecules are anchored

Question 11

M line

Answer 11

the scaffold holding myosin in place

Question 12

H band

Answer 12

space between two actin molecules across a sarcomere

Question 13

I band

Answer 13

isotropic band, light band, actin

Question 14

A band

Answer 14

anisotropic, dark band, myosin

Question 15

cross-bridge

Answer 15

allows for movement, creates a powerstroke to move Z lines closer together

Question 16

ratio of actin to myosin

Answer 16

2:1, actin:myosin

Question 17

what percent volume is actin in muscle cells?

Answer 17

80%

Question 18

tropomyosin

Answer 18

regulatory protein, stiff filament, lays on actin globule to prevent cross-bridge formation,

Question 19

troponin

Answer 19

regulatory protein, anchors tropomyosin to actin, Ca 2+ binding protein

Question 20

myosin structure

Answer 20

six polypeptide subunits forming a dimer

Question 21

twitch

Answer 21

1. latency
2. contraction
3. relaxation

Question 22

latency

Answer 22

period of excitation-contraction coupling