Chapter 7 - The Muscular System

Question 1

What are the bundles of muscle fiber called?

Answer 1

Fascicles

Question 2

The sheath of connective tissue covering fascicles is called:

Answer 2

perimysium

Question 3

Each muscle fiber is covered by a thin layer of areolar connective tissue called the

Answer 3

endomysium

Question 4

Muscles are covered by a layer called _________ which blends with the ____ ______, the layer that surrounds a group of muscles

Answer 4

epimysium, deep fascia

Question 5

Put the three connective tissue coverings for a muscle (perimysium, endomysium, epimysium) in order from superficial to deep

Answer 5

Epimysium (superficial), perimysium, endomysium (deep)

Question 6

Function of the sarcolemma (plasma membrane of a muscle fiber)

Answer 6

Forms T tubules

Question 7

Function of the sarcoplasm (cytoplasm of a muscle fiber that contains organelles)

Answer 7

Contains myofibrils

Question 8

Function of glycogen

Answer 8

Provides energy for muscle contraction

Question 9

Function of myoglobin

Answer 9

Stores oxygen for muscle contraction

Question 10

Function of T tubules

Answer 10

Conveys nerve signals that cause Ca^2+ to be released from the sarcoplasmic reticulum into the sarcoplasm

Question 11

Function of sarcoplasmic reticulum

Answer 11

Stores Ca^2+

Question 12

Function of myofibril

Answer 12

Contraction

Question 13

Function of myofilament

Answer 13

Allows for muscle striation and contraction

Question 14

Thick muscle filaments are made up of a single protein called

Answer 14

myosin

Question 15

Thin muscle filaments are made of three proteins:

Answer 15

actin, tropomyosin, troponin

Question 16

The mechanism behind skeletal muscle contraction is a phenomenon called the

Answer 16

sliding filament theory

Question 17

A motor unit consists of

Answer 17

A single motor nerve axon and an entire collection of muscle fibers

Question 18

What is the name of the junction between a neuron and muscle fiber?

Answer 18

The neuromuscular junction

Question 19

Axon terminals contain synaptic vesicles that are filled with

Answer 19

acetylcholine (ACh)

Question 20

How does the botulism toxin (Botox) paralyze muscle?

Answer 20

By blocking the release of acetylcholine from the motor neuron

Question 21

What does anaerobic mean?

Answer 21

Does not require oxygen

Question 22

What is creatine phosphate?

Answer 22

High energy compound built up during muscle relaxation

Question 23

Fermentation supplies ATP with or without the use of oxygen?

Answer 23

Without oxygen

Question 24

The portion of the muscle cell membrane that extends into the muscle and conveys nerve signals is called

Answer 24

transverse (T) tubules

Question 25

What are the three stages of a muscle twitch?

Answer 25

Latent period, contraction period, relaxation period

Question 26

Tetanic contraction is

Answer 26

a sustained muscle contraction without relaxation

Question 27

What is the all-or-none law for muscle cells and neurons?

Answer 27

For muscle cells, property of muscle that states that a muscle cell contracts completely or not at all. For neurons, property states that neurons either conduct a nerve signal completely or not at all

Question 28

What is recruitment?

Answer 28

Increase in the number of motor units activated as intensity of stimulation increases

Question 29

What is the continuous, partial contraction of muscle called?

Answer 29

Tone

Question 30

Wasting away or decrease in size of an organ or tissue is called

Answer 30

Muscular atrophy

Question 31

Increase in the size of an organ, usually by an increase in the size of its cells is called

Answer 31

Musucular hypertrophy

Question 32

Define origin vs insertion

Answer 32

Origin: end of a muscle that is attached to a relatively immovable part Insertion: end of a muscle that is attached to a movable part

Question 33

What are assisting muscles called?

Answer 33

synergists

Question 34

Which muscle is named for its shape: latissimus dorsi, triceps brachii, gluteus maximus, frontalis?

Answer 34

latissimus dorsi

Question 35

What facial expression is caused by the frontalis muscle?

Answer 35

Raise eyebrow and wrinkle brow

Question 36

What facial expression is caused by the orbicularis oculi muscle?

Answer 36

Closing of the eye or blinking

Question 37

What facial expression is caused by the orbicularis oris muscle?

Answer 37

Puckering the lips

Question 38

What facial expression is caused by the zygomaticus muscle?

Answer 38

Raises the corners of the mouth when smiling