Muscle Tissues Flashcards Preview

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Flashcards in Muscle Tissues Deck (43):
1

An entire skeletal muscle is surrounded by _________.

epimysium

2

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

motor unit

3

What does not occur during skeletal muscle contraction?

Calcium binds to myosin heads.

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?

Ca^(2+)

5

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

Neuromuscular junction

6

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

terminal cisterna, transverse tubule, and terminal cistern.

7

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

myosin

8

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

epimysium

9

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

sarcomere

10

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

synaptic cleft

11

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

tone

12

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

isometric

13

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

fibers are small and spindle-shaped

14

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

lactic acid

15

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

action potential

16

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

calmodulin

17

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

recoil and resume its resting length after being stretched

18

What muscle in the arm is voluntary?

The muscle that extends the arm at the elbow

19

A sarcomere is part of a(n)________.

myofibril

20

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

globular head of thick filaments

21

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

peristalsis

22

What characteristic is unique to smooth muscle?

the absence of striations

23

T or F
Cardiac muscle control is voluntary

False

24

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

True

25

T or F
Cross bridges are formed by the actin molecules.

False

26

T or F
During the recovery period after exercise, the body's need for oxygen is increased.

True

27

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

True

28

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

True

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.

False

30

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

False

31

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

True

32

T or F
The neurotransmitter that stimulates skeletal muscle is acetylcholine.

True

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.

True

34

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

True

35

T or F
The space between the neuron and the muscle is the axon terminal.

False

36

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

False

37

T or F
Thick filaments consist mainly of the protein actin.

False

38

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

True

39

T or F
Cross bridge attachment to actin requires K+.

False

40

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

False

41

T or F
Ca++ is essential for skeletal muscle contraction.

True

42

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

False

43

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

True