Muscle Tissue

Question 1

The functional unit of skeletal muscle is called a ____________

Answer 1

sarcomere

Question 2

Which of the following is NOT a function of muscles in the human body?

Answer 2

all of the above are functions of muscles in the human body

Question 3

______________ muscle is a voluntary muscle that usually connects two bones, _____________ muscle is an involuntary, fatigue-resistant muscle found exclusively in the heart, and ______________ muscle is an involuntary muscle found in viscera (internal organs).

Answer 3

skeletal; cardiac; smooth

Question 4

Human muscles are powered by _____________, which is generated in the body through _______________.

Answer 4

ATP; cellular respiration

Question 5

extensibility

Answer 5

can stretch or extend

Question 6

elasticity

Answer 6

can recoil back to original position

Question 7

excitability

Answer 7

can generate electricity

Question 8

contractility

Answer 8

can shorten with force and pull on attachment points

Question 9

The generic name for a protein that transmits a neuron’s signal from one neuron to another, or from a neuron to a muscle fiber (muscle cell) is called

Answer 9

a neurotransmitter

Question 10

The site at which the nerve and muscle come together is called the

Answer 10

neuromuscular junction

Question 11

A bundle of muscle fibers (muscle cells) is called a ________________.

Answer 11

fascicle

Question 12

The specific neurotransmitter that sends the signal from a motor neuron to muscles is

Answer 12

acetylcholine

Question 13

The neurons that carry the signals from the brain to effectors, such as muscles, to carry out their effects, such as movement, are called ______________

Answer 13

motor neurons

Question 14

In order for actin and myosin to be able to carry out their function, ______________ must first rush into the cell to remove the molecule that normally blocks them from grabbing and sliding across each other.

Answer 14

calcium

Question 15

The ion that depolarizes (flips the electric charge) of a muscle cell is _____, and the ion that repolarizes (resets the electric charge) is _____.

Answer 15

Na+; K+

Question 16

_______________ is the constant state of partial muscle contraction maintained by the central nervous system. _______________ is when the muscles are more flaccid and weak than they should be and ______________ is when they are too rigid, spastic, and overactive.

Answer 16

muscle tone; hypotonia; hypertonia

Question 17

Muscle contractions in which a muscle is flexed without moving (like when holding a textbook straight out in front of you) are called _____________ contractions.

Answer 17

isometric

Question 18

In order for a muscle to have optimal contraction when needed, the sarcomeres should be _____________ at rest.

Answer 18

at their optimal length

Question 19

A group of muscle fibers innervated by the same motor neuron are called a

Answer 19

motor unit

Question 20

Activating more and more motor units in a muscle to reach the required strength for a given task is called

Answer 20

recruitment

Question 21

Isotonic muscle contractions in which the muscle is lengthening while contracting (like when slowly extending your arm to put something down gently) are called ______________ contractions.

Answer 21

eccentric

Question 22

Resistance (strength) training triggers all of the following EXCEPT:

Answer 22

the formation of more muscle cells (hyperplasia)

Question 23

Endurance exercise triggers all of the following EXCEPT:

Answer 23

the formation of more muscle cells (hyperplasia)

Question 24

Which of the following performance enhancing substances is NOT correctly paired with its effect?

Answer 24

creatine: increases muscle mass and endurance

Question 25

Burst activities, like sprinting, use anaerobic _____________ fibers, while high endurance activities like marathons or posture use aerobic _____________ fibers, and the ____________ fibers fall in between for activities like walking.

Answer 25

fast glycolytic; slow oxidative; fast oxidative (intermediate)

Question 26

Smooth muscle heals through

Answer 26

all of the above

Question 27

In cardiac muscle, the desmosomes function to

Answer 27

prevent the cells from pulling apart

Question 28

Which of the following is NOT true regarding cardiac muscle cells?

Answer 28

They have multiple nuclei due to multiple stem cells fusing during their formation

Question 29

Which of the following is NOT true regarding smooth muscle cells?

Answer 29

They are composed of functional units called sarcomeres

Question 30

Smooth muscle contractions can be stimulated by

Answer 30

all of the above

Question 31

Skeletal and cardiac muscle heal through

Answer 31

hyperplasia

Question 32

Identify the two types of myofilaments.

Answer 32

thin (actin) and thick (myosin)

Question 33

Identify the 2 molecules that Ca2+ moves out of the way to expose the binding sites on actin:

Answer 33

troponin and tropomyosin

Question 34

The ___________________ is defined as the region between two z-lines.

Answer 34

sarcomere

Question 35

Identify 3 sources of ATP for muscle contraction:

Answer 35

creatine phosphate, glycolysis, and aerobic respiration

Question 36

Identify 2 possible causes of muscle fatigue:

Answer 36

Lack of ATP; Lactic acid buildup affecting pH and enzymes; Na+ and K+ imbalances from repeated use; sarcoplasmic reticulum and/or sarcolemma damage affecting Ca2+ regulation