Chapter 8 - Muscular System

Question 1

3 names for skeletal muscle

Answer 1

Skeletal, striated, voluntary

Question 2

3 types of muscles

Answer 2

Skeletal, smooth, cardiac

Question 3

Skeletal muscle

Answer 3

Characterized by threadlike bundles with striations and multiple nuclei

Question 4

Cardiac muscle

Answer 4

Muscle of the heart. Have intercalated disks. Interconnected nature makes an efficient heart.

Question 5

Intercalated disks

Answer 5

Dark bands in cardiac muscle where plasma membranes of adjacent fibers make contact.

Question 6

Smooth muscle

Answer 6

Tapered at each end and have a single nucleus. Non-striated. Involuntary. Blood vessels. Digestive tract

Question 7

Fascicles

Answer 7

Group of muscle fibers wrapped in connective tissue.

Question 8

Fascia

Answer 8

Loose connective tissue around a muscle organ that forms a flexible sticky packing material around muscles, bones and the skin

Question 9

Origin

Answer 9

Muscle attached to a stationary bone

Question 10

Insertion

Answer 10

Muscle attached to a movable bone

Question 11

Tendons

Answer 11

Attach muscle to bone

Question 12

Thick myofilament

Answer 12

Threadlike microfilament of muscle that is formed from myosin

Question 13

Thin myofilaments

Answer 13

Threadlike microfilament of muscle made of actin

Question 14

Sacromere

Answer 14

Basic contractile unit of skeletal muscle. Numerous thick and thin myofilaments.

Question 15

Sliding filament model

Answer 15

Thick and thin myofilaments attach to one another forming cross bridges that act as levers and ratchet myofilaments past each other.

Question 16

Myoglobin

Answer 16

Red, oxygen storing part of muscle. Used during quick muscle contractions in addition to hemoglobin oxygen to maximize ATP recharging.

Question 17

Eccentric contraction

Answer 17

Tension during muscle lengthening. Like when lowering a bowling ball from the shoulder

Question 18

Tonic contraction

Answer 18

Continuous low strength muscle contraction to hold in position. Posture.

Question 19

3 functions of skeletal muscle

Answer 19

Movement, posture, heat production

Question 20

Motor neuron

Answer 20

Nerve fiber that stimulates muscles

Question 21

Neuromuscular junction

Answer 21

Point of contact between nerve ending and muscle fiber

Question 22

Acetylcholine

Answer 22

Neurotransmitter that operates in neuromuscular junction

Question 23

Motor unit

Answer 23

Single motor neuron and the muscle it innervates

Question 24

Threshold stimulus

Answer 24

Minimum level of stimulation to produce muscle contraction.

Question 25

Types of muscle contraction

Answer 25

Tonic, twitch, tetanic, isotonic, isometric

Question 26

Twitch contraction

Answer 26

Quick, jerky response to stimulus. Minimal role in normal muscle activity.

Question 27

Tetanic contraction

Answer 27

More sustained and steady response than a twitch. Melt together to produce sustained contraction called tetanus. Not a unified contraction

Question 28

Isotonic contraction

Answer 28

Movement at a joint. 2 types. Concentric and eccentric. Walking running breathing lifting twisting.

Question 29

Isometric contraction

Answer 29

Contraction with no movement.

Question 30

Concentric contraction

Answer 30

Muscle shortens during movement

Question 31

Disuse atrophy

Answer 31

Prolonged inactivity of muscles. Muscles shrink in mass

Question 32

Hypertrophy

Answer 32

Increase in muscle size.

Question 33

Flexion

Answer 33

Movement that makes the angle between two bones at a joint smaller.

Question 34

Extension

Answer 34

Movement between two joint where the angle between increases.

Question 35

Abduction

Answer 35

Moving part of the body away from the midline of the body.

Question 36

Adduction

Answer 36

Movement toward the midline of the body

Question 37

Rotation

Answer 37

Movement around a longitudinal axis. Shaking your head no

Question 38

Circumduction

Answer 38

Movement so the distal end moves in a circle.

Question 39

Dorsiflexion

Answer 39

Elevated foot with toes pointing upward

Question 40

Plantar flexion

Answer 40

Toes pointed down

Question 41

Inversion

Answer 41

Arch of the foot pointed up

Question 42

Eversion

Answer 42

Arch of the foot pointed down