Chapter 7 Davis

Question 1

1. The unit of contraction in a muscle fiber

Answer 1

sarcomere

Question 2

The very large extensor of the thigh

Answer 2

gluteus maximus

Question 3

Transmits action potential for contraction

Answer 3

sarcolemma

Question 4

Integrates unconscious muscle sense

Answer 4

cerebellum

Question 5

State of slight contraction of muscles

Answer 5

muscle tone

Question 6

Dome-shaped respiratory muscle

Answer 6

diaphragm

Question 7

Neurotransmitter at neuromuscular junctions

Answer 7

acetylcholine

Question 8

Releases the energy of A T P

Answer 8

myosin

Question 9

Why are muscle actions grouped in such pairs?

Answer 9

Muscle actions are grouped in pairs, because a muscle can only pull a bone, not push. A muscle pulls in one direction. Another muscle is needed to pull in the opposite direction.

These are antagonistic functions or pairs of opposites.

Question 10

Most muscle actions are in pairs:

Flexion—

Answer 10

extension

Question 11

Most muscle actions are in pairs:

Abduction—

Answer 11

adduction

Question 12

Most muscle actions are in pairs:

Inversion—

Answer 12

eversion

Question 13

Most muscle actions are in pairs:

Pronation—

Answer 13

supination

Question 14

the inability of muscles to contract

Answer 14

Paralysis

Question 15

In response to a single nerve impulse, a muscle fiber will contract completely (all of the sarcomeres contract) and then relax

Answer 15

Twitch

Question 16

The functions of the muscular system are to:

Answer 16

1. Move the skeleton
2. Produce heat

Question 17

Name the tissues that make up the parts of the muscular system.

Answer 17

The skeletal muscles are made of skeletal muscle tissue, also called striated or voluntary muscle tissue.

Tendons are made of fibrous connective tissue.

The fascia around each muscle is also made of fibrous connective tissue.

Question 18

Tendons are made of

Answer 18

fibrous connective tissue.

Question 19

The fascia around each muscle is made of

Answer 19

fibrous connective tissue

Question 20

The organ systems directly necessary for movement are the:

Answer 20

1. Skeletal system
2. Nervous system
3. Respiratory system
4. Circulatory system

Question 21

The skeletal system is moved by

Answer 21

muscles

Question 22

The nervous system transmits

Answer 22

electrochemical impulses to muscles.

Question 23

The respiratory system exchanges O2 and C O2 between

Answer 23

the air and the blood.

Question 24

The circulatory system transports

Answer 24

O2 to muscles and takes C O2 away.

Question 25

One muscle is made of thousands of

Answer 25

muscle fibers.

Question 26

Muscle fibers

Answer 26

contract, shorten, and bring about movement.

Question 27

Tendons attach muscles to

Answer 27

bone

Question 28

A tendon merges with

Answer 28

the fascia of the muscle and the periosteum of the bone.

Question 29

the state of slight contraction present in healthy muscles; regulated by the cerebellum

Answer 29

Muscle Tone

Question 30

the direct source

Answer 30

A T P

Question 31

for the resynthesis of A T P

Answer 31

Creatine phosphate

Question 32

a nitrogenous waste product.

Answer 32

Creatinine

Question 33

most abundant, stored in muscles •First broken down to glucose •Glucose + O2  C O2 + H2O + A T P + heat

Answer 33

Glycogen

Question 34

What happens to each of the products of cell respiration?

Answer 34

C O2 is exhaled. Water becomes part of intracellular fluid. A T P is used for the contraction process. Heat contributes to body temperature.

Question 35

Name the cell organelle that is the site of cell respiration.

Answer 35

The mitochondria are the sites of cell respiration.

Question 36

The brain creates a mental picture: Unconscious muscle sense is essential for

Answer 36

coordination in the cerebellum

Question 37

The brain creates a mental picture: Conscious muscle sense is in

Answer 37

the parietal lobes

Question 38

knowing where our muscles are without seeing them

Answer 38

Muscle Sense (proprioception)

Question 39

Stretch receptors (proprioceptors) in muscles detect

Answer 39

stretching, generate impulses.

Question 40

the outside of the sarcolemma becomes negative relative to the inside.

Answer 40

Depolarization

Question 41

the sarcolemma has a (+) charge outside and a (negative) charge inside.

Answer 41

Polarization (resting potential)

Question 42

Electrical charges outside and inside the membrane are created by

Answer 42

the presence and movement of ions.

Question 43

Sliding Filament Mechanism Nerve impulse arrives at the axon terminal and

Answer 43

A c h is released.

Question 44

Sliding Filament Mechanism A c h  A c h receptors on the sarcolemma; N a+ ions enter

Answer 44

the cell.

Question 45

Sliding Filament Mechanism The sarcolemma

Answer 45

depolarizes.

Question 46

Sliding Filament Mechanism With depolarization: C a+2 ions are released from the _______; C a+2 ions bond to _______.

Answer 46

sarcoplasmic reticulum; troponin-tropomyosin

Question 47

Sliding Filament Mechanism Myosin splits

Answer 47

A T P.

Question 48

Sliding Filament Mechanism Myosin bridges pull the actin filaments to the

Answer 48

center of the sarcomere.

Question 49

Sliding Filament Mechanism All of the sarcomeres in a muscle fiber

Answer 49

shorten.

Question 50

Sliding Filament Mechanism The sarcolemma

Answer 50

repolarizes.

Question 51

Sliding Filament Mechanism Cholinesterase inactivates

Answer 51

A c h.

Question 52

Sliding Filament Mechanism Subsequent nerve impulses:

Answer 52

prolong contraction.

Question 53

Sliding Filament Mechanism No further impulses:

Answer 53

the muscle fiber relaxes.

Question 54

The origin of a muscle is the

Answer 54

More stationary bone

Question 55

The insertion of a muscle is the

Answer 55

More movable bone

Question 56

have opposite functions. A muscle pulls when it contracts but exerts no force when it relaxes and it cannot push. When one muscle pulls a bone in one direction, another muscle is needed to pull the bone in the other direction

Answer 56

Antagonistic muscles

Question 57

have the same function and alternate as the prime mover depending on the position of the bone to be moved. also stabilize a joint to make a more precise movement possible.

Answer 57

Synergistic muscles

Question 58

generate the impulses necessary for contraction of skeletal muscles. The cerebellum regulates coordination.

Answer 58

The frontal lobes of the cerebrum

Question 59

A muscle can only

Answer 59

pull a bone

Question 60

helps maintain posture, produces 25% of body heat (at rest), and improves coordination.

Answer 60

Good muscle tone

Question 61

involves contraction with movement; improves tone and strength and improves cardiovascular and respiratory efficiency (aerobic exercise).

Answer 61

Isotonic exercise

Question 62

Isotonic exercise: Concentric contraction —

Answer 62

muscle exerts force while shortening.

Question 63

Isotonic exercise: Eccentric contraction-

Answer 63

muscle exerts force while returning to its original length.

Question 64

involves contraction without move-ment; improves tone and strength but is not aerobic.

Answer 64

Isometric exercise

Question 65

Exercise stimulates skeletal muscle cells to secrete the hormone irisin, which converts fat-storing white adipocytes to thermogenic brown or beige adipocytes.

Answer 65

Important information

Question 66

Hemoglobin in R B C's carries

Answer 66

Oxygen to muscles

Question 67

Myoglobin in muscle cells stores

Answer 67

Oxygen in muscles

Question 68

Lactic acid is formed in place of C O2 and H2O:

Answer 68

which lowers cellular pH and contributes to fatigue.

Question 69

Oxygen debt (recovery oxygen uptake):

Answer 69

Muscle fibers run out of oxygen during strenuous exercise

Question 70

Neuromuscular junction: axon terminal and sarcolemma:

Answer 70

the synapse is the space between them.

Question 71

The axon terminal contains

Answer 71

acetylcholine (a neurotransmitter)

Question 72

the sarcolemma contains

Answer 72

cholinesterase (an inactivator)

Question 73

Sarcomeres are the

Answer 73

contracting units of a muscle fiber.

Question 74

Myosin and actin filaments are the

Answer 74

contracting proteins of sarcomeres.

Question 75

Troponin and tropomyosin are proteins that inhibit

Answer 75

the sliding of myosin and actin when the muscle fiber is relaxed

Question 76

The sarcoplasmic reticulum surrounds the sarcomeres and is a reservoir for

Answer 76

calcium

Question 77

(Polarization) N a+ ions are more abundant

Answer 77

outside the cell

Question 78

(Polarization) K+ ions are more abundant

Answer 78

inside the cell

Question 79

(Polarization) The sodium and potassium pumps maintain these relative concentrations on

Answer 79

either side of the sarcolemma

Question 80

. is the exit of K+ ions and the restoration of a positive (+) charge outside.

Answer 80

Repolarization

Question 81

T tubules are

Answer 81

Folds up of the sarcolemma

Question 82

makes the sarcolemma permeable to N a+

Answer 82

A c h

Question 83

a sustained contraction brought about by continuous nerve impulses; all our movements involves it.

Answer 83

Tetanus

Question 84

Muscles that do not receive nerve impulses are unable to contract and will atrophy.

Answer 84

Paralysis

Question 85

Paralysis may be the result of

Answer 85

nerve damage, spinal cord damage, or brain damage.

Question 86

The end of a motor neuron; contains vesicles of acetylcholine that are opened by the arrival of a nerve impulse

Answer 86

Axon terminal

Question 87

The enzyme that inactivates acetylcholine; prevents continued depolarization and contraction

Answer 87

Cholinesterase

Question 88

The neurotransmitter released by the axon terminal; it diffuses across the synaptic cleft, bonds to the ACh receptors, and brings about depolarization of the sarcolemma with an influx of Na* ions

Answer 88

Acetylcholine (ACh)

Question 89

The space between the axon terminal and the sarcolemma

Answer 89

Synaptic cleft

Question 90

Proteins of the sarcolemma that are channels for Na+ ions; are opened by acetylcholine

Answer 90

Acetylcholine receptors

Question 91

The cell membrane of the muscle fiber; has receptors for acetylcholine

Answer 91

Sarcolemma