Exam 3

Question 1

What muscle group is striated and voluntary?

Answer 1

Skeletal Muscle

Question 2

What muscle group is striated and involuntary?

Answer 2

Cardiac Muscle

Question 3

What muscle group is unstriated and involuntary?

Answer 3

Smooth Muscle

Question 4

What is the term for single skeletal muscle cells?

Answer 4

Muscle Fiber

Question 5

A single motor neuron and all the muscle fiber it innervates?

Answer 5

A motor unit

Question 6

Site where a motor neuron stimulates a muscle fiber

Answer 6

Neuromuscular junction

Question 7

Area of the muscle fiber sarcolemma where a motor neuron stimulates it using ACh

Answer 7

Motor end plate

Question 8

Contractile elements of muscle fiber containing bundles of thick and thin filaments

Answer 8

Myofibrils

Question 9

Filaments made from myosin protein

Answer 9

Thick filaments

Question 10

Filaments made from actin protein

Answer 10

Thin filaments

Question 11

What forms striations in the myofibrils

Answer 11

alternating dark A bands and light I bands

Question 12

A functional unit in between 2 Z lines of skeletal muscle

Answer 12

Sarcomere

Question 13

Forms cross bridge between thick and thin filaments

Answer 13

Myosin heads

Question 14

3 units of myosin heads

Answer 14

Actin Binding Site
ATP Binding Site
ATPase

Question 15

Type of contractile protein

Answer 15

Actin

Question 16

Regulatory proteins

Answer 16

Tropomyosin

Troponin

Question 17

Results in contraction of muscle fiber

Answer 17

Binding of actin binding site with myosin cross bridge

Question 18

This protein is resting, covers myosin binding sites blocking interaction

Answer 18

Tropomyosin

Question 19

What are the 3 units Troponin is made of?

Answer 19

Binds to tropomyosin
Binds to actin
Binds with Ca2+

Question 20

Thin filaments from opposite sides of each sarcomere sliding closer together between thick filaments results in what?

Answer 20

Contraction

Question 21

In the sliding filament mechanism, what happens after attachment of a cross bridge to a thin filament (what is step 2)

Answer 21

Movement of the cross bridge, producing movement of the thin filament

Question 22

In the sliding filament mechanism, what happens after movement of the cross bridge? (what is step 3)

Answer 22

Detachment of the cross bridge from the thin filament

Question 23

Last step of sliding filament mechanism

Answer 23

Movement of the cross bridge into a position where it can again reattach to a thin filament and repeat cycle

Question 24

Functions of ATP in contraction

Answer 24

Energizes and dissociates x-bridge from actin

Question 25

Excitation Contraction Coupling role?

Answer 25

Release of Ca++ by opening of Ca++ voltage channels

Question 26

How is calcium released?

Answer 26

AP propagated (spread) into interior of fiber along transverse tubules to sarcoplasmic reticulum; opening of voltage channels

Question 27

Action potential results in release of what inside muscle fiber?

Answer 27

Ca2+

Question 28

What occurs when local action potential is no longer present?

Answer 28

Ca2+ moves back into sarcoplasmic reticulum

Question 29

Requirements of ATP

Answer 29

- ATP splitting by myosin ATPase provides energy | -