Ch 11.1-11.4

Question 1

muscle and nerve cells have developed which characteristic more than other cells?
A. Movement
B. Permeability
C. Excitability 
D. Reproduction

Answer 1

C. Excitability

Question 2

Because skeletal muscles is under the conscious control it is staid to be \_\_\_\_\_\_\_\_\_.
A. Involuntary
B. Smooth
C. Voluntary 
D. Visceral

Answer 2

C. voluntary

Question 3

Muscle cells contain __________, a starch-like carbohydrate that provides energy during intense exercise.

Answer 3

glycogen

Question 4

What is myoglobin?
A. An enzyme found in the synaptic cleft
B. A molecule that stores oxygen in muscles
C. A carbohydrate that provides a muscle cell with energy
D. A hormone that triggers contraction

Answer 4

B. A molecule that stores oxygen in muscles

Question 5

Which membranous structures conduct impulses through the sarcoplasm to stimulate the release of calcium?

A. Troponin
B. Sarcomeres
C. Myosin
D. T-tubules

Answer 5

D. T-tubules

A. troponin is a regulatory protein.
B. A sarcomere is the portion of the myofibril from one Z disc to the next; it constitutes one contractile unit.
C.Myosin is a contractile protein.

Question 6

The characteristic that allows muscles to pull on bones and organs to create movement is called_____.

A. metabolism
B. Excitability
C. Contractility
D. Conductivity

Answer 6

C. Contractility

Question 7

True or false.

The sarcoplasmic reticulum releases calcium through gated channels when the T-tubules are stimulated.

Answer 7

true

Question 8

skeletal muscles exhibits alternating light and dark bands called_________.

Answer 8

striations

Question 9

In a myofibril, a thick filament is composed of pairs of ___________ molecules intertwined together.

Answer 9

myosin

Question 10

muscle cells contain _____________, a red pigment that stores oxygen need for muscular activity.

Answer 10

myoglobin

Question 11

Thin filaments are primarily composed of which protein?
A. F actin
B. Elastin
C. Dystrophin
D. Myosin

Answer 11

A. F actin

Question 12

what is the function of T-tubules?
A. to stimulate the terminal cisternae to release sodium
B. to stimulate the terminal cisternae to release calcium
C. to stimulate the terminal cisternae to release acetylcholine

Answer 12

B. to stimulate the terminal cisternae to release calcium

Question 13

gated channels in the sarcoplasmic membrane open to release which ions into the cytosol?
A. Sodium
B. Phosphate
C. Potassium
D. Calcium

Answer 13

D. Calcium

Question 14

In a thin filament, each tropomyosin molecule has a small calcium-binding protein called _________ bound to it.

Answer 14

troponin

Question 15

Which protein makes up the thick filaments of a myofibril?
A. Actin
B. Tropomyosin
C. Troponin
D. Myosin

Answer 15

D. Myosin

Question 16

within skeletal muscle cells, what extends from on Z disc to the next and constitutes one contractile unit?
A. Thick filament
B. Sacromere
C. Terminal Cisterna
D. T-Tubule

Answer 16

B. Sacromere

Question 17

Multi-Select
Which of the following are found in thin filaments?
A. Troponin
B. Tropomyosin
C. F actin
D. Titin 
E. Myosin

Answer 17

A. Troponin
B. Tropomyosin
C. F actin

Question 18

What is a motor unit?
A. all of the muscle fibers innervated by a single motor nerve fiber.
B. A muscle unit within the epimysium
C. All of the nerve fibers that innervate a muscle group
D. A single bundle of fascicles

Answer 18

A. all of the muscle fibers innervated by a single motor nerve fiber.

Question 19

What is myoglobin?
A. a carbohydrate that provides a muscle cell with energy
B. A hormone that triggers contraction
C. A molecule that stores oxygen in muscles
D. An enzyme found in the synaptic cleft

Answer 19

C. A molecule that stores oxygen in muscles

Question 20

What is a neuromuscular junction?

A. a site where a nerve fiber communicated with a muscle fiber
B. A site in the spinal cord where nerve impulses from the somatic receptors are received
C. where a synaptic bulb is attached to a T-tubule
D. A passageway into a muscle for arteries and veins

Answer 20

A. a site where a nerve fiber communicated with a muscle fiber

Question 21

which membranous structures conduct impulses through the sarcoplasm to stimulate the release of calcium?
A. sarcomeres
B. Myosin
C. Troponin
D. T-tubules

Answer 21

D. T-tubules

Question 22

what is acetylcholine?
A. the name of the plasma membrane of a muscle fiber
B. The enzyme that removes the neurotransmitter in the neuromuscular junction.
C. an autoimmune disorder where the immune system attacks ACh receptors
D. The neurotrasmitter release at a neuromuscular junction

Answer 22

D. The neurotrasmitter release at a neuromuscular junction

Question 23

when a muscle is at rest, what molecule blocks the active sites on the actin molecules?
A. Myosin
B. Tropomyosin
C. Troponin

Answer 23

B. Tropomyosin

Question 24

What do neurons and muscles cells have in common?
A. their membranes undergo voltage changes when stimulated
B. Neurons and muscles cells are autorhythmic
C. Neurons and muscles cells are both multinucleated.
D. Both cells shorten when stimulated

Answer 24

A. their membranes undergo voltage changes when stimulated

Question 25

the portion of a myofibril from one Z discus to the next is called ___________.

Answer 25

sarcomere

Question 26

``` What is a difference in electrical charge from one point to another called? A. Charge difference B. Anion gap C. Battery D. Electrical potential ```

Answer 26

D. Electrical potential

Question 27

all of the muscle fibers innervated b a single nerve fiber constitute a _______ unit

Answer 27

motor

Question 28

``` What is the change in membrane potential with the entry of sodium ions called? A. repolarization B. Hyperpolarization C. Depolarization D. Unpolarizaton ```

Answer 28

C. Depolarization

Question 29

A synapse is the point where a nerve fiber meets a target cell. When the target cell is a muscle fiber this type of synapse is called _______ junction.

Answer 29

neuromuscular

Question 30

What is the process by which action potentials of a nerve fiber lead to action potentials in the muscle fiber called? A. contraction B. excitation C. polarization

Answer 30

B. excitation

Question 31

``` the neurotransmitter used in a neuromuscular junction is ______. A. Adrenaline B. Acetylcholine C. Norepinephrine D. GABA ```

Answer 31

B. Acetylcholine

Question 32

``` at the synaptic knob of the motor neuron, calcium stimulates exocytosis of the synaptic vesicles to release the neurotransmitter ________ into the synapse. A. GABA B. Glucagon C. Sodium D. Acetylcholine ```

Answer 32

D. Acetylcholine

Question 33

``` which cells have plasma membranes that undergo voltage changes in response to stimuli? A. Neurons and muscle cells B. Osteocytes and muscles cells C. Glial cells and osteocytes D. Glial cells and muscles cells ```

Answer 33

A. Neurons and muscle cells

Question 34

what is the function of a t-tubule A. carry the action potential through the sarcoplasm B. are one component of the rigor complex C. store ACh D. Store and phosphorylate ATP needed for contraction

Answer 34

A. carry the action potential through the sarcoplasm

Question 35

the voltage measured across the muscle cell at rest is about -90mV and is called resting membrane _____________.

Answer 35

Potential

Question 36

Action potentials cause the opening of voltage-gated sodium ion channels in the ______ tubules. this leads to the opening of calcium ion channels in the terminal cisternae of the sarcoplasmic reticulum.

Answer 36

T or transverse

Question 37

``` during depolarization of a muscle cell or nerve cell, ion channels in the plasma membrane open allowing which ions to enter the cell? A. Calcium B. Chloride C. Sodium D. Potassium ```

Answer 37

C. Sodium

Question 38

Which occurs during muscle contraction? A. The myofilaments lengthen B. Myofilaments shorten C. Overlapping of myofilaments decreases D. Overlapping of myofilaments increase

Answer 38

D. Overlapping of myofilaments increase

Question 39

Regarding skeletal muscle contraction, what is excitation? A. the process by which rigor complexes are formed in the sarcomere B. the process by which action potentials in the sarcolemma lead to calcium release C. the stimulus that leads to the stretching of the elastic fibers in sarcomere D. The process by which action potentials in a nerve fiber lead to action potentials in muscle fiber

Answer 39

D. The process by which action potentials in a nerve fiber lead to action potentials in muscle fiber

Question 40

what does the sliding filament theory describe? A. action potential propagation B. Muscle contraction C. Synaptic transmission

Answer 40

B. Muscle contraction