Module 4

Question 1

Skeletal muscle

Answer 1

Attach to and cover bony skeleton Longest muscle fibers Striated, voluntary Can contract rapidly; tires easily & must rest Strong, adaptable

Question 2

Cardiac muscle

Answer 2

Only in heart Striated, involuntary Pacemaker sets rate of contraction; neural input can change rate

Question 3

Smooth Muscle

Answer 3

Walls of hollow, visceral organs Nonstriated, involuntary Slow, sustained contractions

Question 4

What is the function of muscles

Answer 4

1)Excitability: receive and respond to stimulus
2)Contractility: Ability to shorten forcibly when stimulated
3) Extensibility: Ability to be stretched.
4)Elasticity: resume strength after being stretched

Question 5

What does syncytium mean

Answer 5

Single cell containing several nuclei.

Question 6

What thin layer covers

Answer 6

surrounds the entier muscle

Question 7

What covers the fascicle

Answer 7

Perimysium

Question 8

What covers the muscle cell

Answer 8

endomysium

Question 9

I-Band

Answer 9

Covers part from the myosin heads to the next myosin head in the next sacromere.

Question 10

A-Band

Answer 10

Covers from the start of the myosin to the next end

Question 11

H-Band

Answer 11

Covers only myosin stacks that have no arrows.

Question 12

What is Z disk made of

Answer 12

Alpha Acticin

Question 13

What is titin

Answer 13

Strong muscle muscle filaments with corkscrew-like elastic properties

Question 14

What is the plasma membrane of a muscle cell

Answer 14

Sarcolemma

Question 15

What is fasicle

Answer 15

bundle of muscle cells

Question 16

What does rigor mortis tell you about the role of ATP in cross bridge detachment???

Answer 16

As ATP continues to be formed by anaerobic glycolysis, the muscles will remain rigid and will be unable to relax

Question 17

When does relaxation occur?

Answer 17

relaxation occurs as SR reclaims Ca++

Question 18

What are skeletal muscles stimulated by

Answer 18

motor neuron of the somatic NS

Question 19

When does cross bridge cycling end?

Answer 19

Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin

Question 20

What is a muscle twitch

Answer 20

The response of a motor unit to a single action potential of its motor neuron

Question 21

The calcium calmodulin system of contraction regulation is found in:

Answer 21

smooth muscle only.

Question 22

What is excitation-contraction coupling?

Answer 22

events leading to the sliding of myofilaments

Question 23

True or false skeletal muscles contain a mixture of fiber types

Answer 23

true

Question 24

What does myglobons do

Answer 24

store oxygen in muscles cells