ch10pt2

Question 1

neural stimulation of sarcolemma (skeletal muscle contraction) causes

Answer 1

excitation-contraction coupling

Question 2

action potential travels along _-___ to __

Answer 2

t-tubules, SR (sarcoplasmic reticulum)

Question 3

______ is released from SR via ___ ___ ___ _______

Answer 3

calcium, voltage gated ion channels

Question 4

_______ binds to _____, causing tropomyosin to uncover the ____ ____ on actin

Answer 4

calcium, troponin, active site

Question 5

interaction between thick and thin filaments causes the muscle to

Answer 5

contract

Question 6

Contraction of many muscle fibers produces ____ in the muscle

Answer 6

tension

Question 7

intercellular connection between the nervous system and skeletal muscle fiber

Answer 7

neuromuscular junction (NMJ)

Question 8

____ ____ (electrical stimulus) is transferred from neuron to the muscle fiber via a _____

Answer 8

action potential, neurotransmitter

Question 9

Area where calcium ions release onto the sarcolemma

Answer 9

neuromuscular junction

Question 10

type of motor neuron controlling skeletal muscles

Answer 10

somatic motor neurons

Question 11

stretches from neuron to muscle

Answer 11

axon

Question 12

end of each axon branch

Answer 12

synaptic terminal

Question 13

One axon and all the fibers it stimulates

Answer 13

motor unit

Question 14

Action potential stimulates ___ __ ____ of the fibers in a motor unit

Answer 14

all or none

Question 15

Small motor units give _______ control

Answer 15

fine

Question 16

Large motor units give _________.

Answer 16

strength

Question 17

neurotransmitter used to pass signal from neuron to muscle fiber

Answer 17

acetylcholine

Question 18

a narrow space separating the synaptic terminal of the neuron from the opposing motor end plate

Answer 18

synaptic cleft

Question 19

enzyme which breaks down acetylcholine (ACh). present in synaptic cleft

Answer 19

acetylcholinesterase (AChE)

Question 20

When the action potential reaches the neuron’s synaptic terminal, it triggers the exocytosis of ___ into the ________ _____.

Answer 20

acetylcholine (ACh), synaptic cleft

Question 21

ACh diffuses across the
synatpic cleft and binds
to ACh receptors on the
_____ ___ _____. ACh
binding opens ligand-gated
sodium channels. Na+ ions rush into the ___________.

Answer 21

motor end plate, sarcoplasm

Question 22

Action potential reaches a triad
Releasing Ca2+ , uncovering active sites on Actin, allowing Actin and Myosin interaction

Answer 22

excitation-contraction coupling

Question 23

Interaction between Actin and Myosin. Shortening of the Sarcomere.

Answer 23

cross bridge cycle

Question 24

must be present in order to free up active sight on actin

Answer 24

calcium

Question 25

shortening of sarcomere (cross bridge cycle) requires myosin heads to be in “_______” position

Answer 25

cocked

Question 26

___ loads myosin heads into ____ position, therefore requiring energy

Answer 26

ATP, cocked

Question 27

ATP turns to ___ in order to free up energy bond for loading myosin head

Answer 27

ADP + P

Question 28

myosin head pivoting

Answer 28

power stroke

Question 29

myosin head lets go of actin

Answer 29

cross-bridge detachment

Question 30

Duration of neural stimulus, Number of free calcium ions in sarcoplasm, Availability of ATP all affects

Answer 30

contraction duration

Question 31

Ca2+ concentrations fall, Ca2+ detaches from troponin, active sites are re-covered by tropomyosin.

Answer 31

relaxation phase of skeletal muscle

Question 32

_______ does not return muscle to original Length, _______ muscle must contract.

Answer 32

relaxation, opposite

Question 33

A fixed muscular contraction after death. SR breaks down, calcium floods muscle cell, no ATP to bind to myosin and detach cross bridge.

Answer 33

rigor mortis

Question 34

__ releases ____ when a motor neuron stimulates the muscle fiber

Answer 34

SR, Ca2+

Question 35

Free ____ in the sarcoplasm triggers ___________

Answer 35

Ca2+, contraction

Question 36

Contraction is an _____ process requiring ___

Answer 36

active, ATP

Question 37

Relaxation and return to resting length are ______

Answer 37

passive