Muscle Tissues

Question 1

An entire skeletal muscle is surrounded by _________.

Answer 1

epimysium

Question 2

A motor neuron and all the muscle fibers it supplies is called a(n) _________.

Answer 2

motor unit

Question 3

What does not occur during skeletal muscle contraction?

Answer 3

Calcium binds to myosin heads.

Question 4

What is the ion released from the terminal cisternae that combines with troponin and removes the blocking action of tropomyosin, resulting in the formation of cross bridges?

Answer 4

Ca^(2+)

Question 5

Each skeletal muscle fiber is controlled by a neuron at a single________.

Answer 5

Neuromuscular junction

Question 6

Description of the composition of the structure known as a triad in a skeletal muscle fiber

Answer 6

terminal cisterna, transverse tubule, and terminal cistern.

Question 7

In the sliding filament model of muscle contraction, the myofilaments slide over each other, resulting in the overlapping of actin and _______.

Answer 7

myosin

Question 8

The dense layer of collagen fibers that surround an entire skeletal muscle is the ________.

Answer 8

epimysium

Question 9

The functional unit of contraction in a skeletal muscle fiber is the ______.

Answer 9

sarcomere

Question 10

The space between the neuron and the muscle is the _______.

Answer 10

synaptic cleft

Question 11

The term that means a continued mild or partial contraction of a muscle that keeps it healthy and ready to respond is muscle _________.

Answer 11

tone

Question 12

The type of muscle contraction in which the muscle fibers produce increased tension, but the muscle neither shortens nor lengthens, is called __________.

Answer 12

isometric

Question 13

What do you know about the fibers in smooth muscle tissue?

Answer 13

fibers are small and spindle-shaped

Question 14

What substance increases in quantity during repetitive muscle contraction during oxygen deficit?

Answer 14

lactic acid

Question 15

The sequence of electrical changes that occurs along the sarcolemma when a muscle fiber is stimulated is known as the _______.

Answer 15

action potential

Question 16

What binds calcium ions in a smooth muscle, causing contractions?

Answer 16

calmodulin

Question 17

Elasticity refers to the ability of a muscle fiber to _________.

Answer 17

recoil and resume its resting length after being stretched

Question 18

What muscle in the arm is voluntary?

Answer 18

The muscle that extends the arm at the elbow

Question 19

A sarcomere is part of a(n)________.

Answer 19

myofibril

Question 20

“cross bridges” that link between the thick and thin filaments are formed by the __________.

Answer 20

globular head of thick filaments

Question 21

The alternating contraction and relaxation of opposing layers of smooth muscle is referred to as ________.

Answer 21

peristalsis

Question 22

What characteristic is unique to smooth muscle?

Answer 22

the absence of striations

Question 23

T or F

Cardiac muscle control is voluntary

Answer 23

False

Question 24

T or F

Communication between neurons and skeletal muscle fibers occurs at specialized junctions called neuromuscular junctions.

Answer 24

True

Question 25

T or F

Cross bridges are formed by the actin molecules.

Answer 25

False

Question 26

T or F

During the recovery period after exercise, the body’s need for oxygen is increased.

Answer 26

True

Question 27

T or F
In isotonic contractions, the muscle changes in length and the tension remains constant through most of the contractile period.

Answer 27

True

Question 28

T or F

Lactic acid is an end product of anaerobic fermentation that contributes to muscle fatigue.

Answer 28

True

Question 29

T or F
Muscles that exert very fine control (such as the muscles controlling movements of the fingers and eyes) have large motor units.

Answer 29

False

Question 30

T or F

One of the functions of the smooth muscle tissue is to force blood from the heart into the major arteries.

Answer 30

False

Question 31

T or F

The area of the sarcomere that contains only thin and elastic filaments is the I band.

Answer 31

True

Question 32

T or F

The neurotransmitter that stimulates skeletal muscle is acetylcholine.

Answer 32

True

Question 33

T or F
The sequence of events that forms the link between electrical activity in the sarcolemma and the initiation of a contraction is called excitation-contraction coupling.

Answer 33

True

Question 34

T or F

The skeletal muscle complex known as the triad consists of the transverse tubule and the terminal cisternae.

Answer 34

True

Question 35

T or F

The space between the neuron and the muscle is the axon terminal.

Answer 35

False

Question 36

T or F

The type of muscle fiber that is most resistant to fatigue is the fast fiber.

Answer 36

False

Question 37

T or F

Thick filaments consist mainly of the protein actin.

Answer 37

False

Question 38

T or F

Cross bridges occur when myosin heads combine with the binding sites on actin.

Answer 38

True

Question 39

T or F

Cross bridge attachment to actin requires K+.

Answer 39

False

Question 40

T or F
In the initial stages of repolarization, the ionic conditions are restored, returning the membrane to its resting potential.

Answer 40

False

Question 41

T or F

Ca++ is essential for skeletal muscle contraction.

Answer 41

True

Question 42

T or F

Subthreshold stimuli result in only a small amount of muscle response movement.

Answer 42

False

Question 43

T or F

At maximal stimulus, the muscle is contracting at full strength and all motor units are recruited.

Answer 43

True