Muscular System

Question 1

Skeletal Muscle

Answer 1

Voluntary, striated, used for movement

Question 2

Cardiac Muscle

Answer 2

Involuntary, striated, found in the heart

Question 3

Smooth Muscle

Answer 3

Involuntary, non-striated, controls organ function

Question 4

What are the functions of muscles in vertebrates?

Answer 4

Locomotion (walking, flying, swimming).

Circulatory regulation (heart contractions, blood vessel control).

Digestion (peristalsis in smooth muscle).

Thermoregulation (shivering in mammals).

Question 5

Epimysium

Answer 5

Surrounds the entire muscle

Question 6

Perimysium

Answer 6

Surrounds muscle fascicles (bundles)

Question 7

Endomysium

Answer 7

Surrounds individual muscle fibers (cells)

Question 8

Sarcomere

Answer 8

The contractile unit, composed of actin (thin filaments) and myosin (thick filaments)

Question 9

Muscle contraction occurs when:

Answer 9

Myosin heads bind to actin.
ATP provides energy for cross-bridge movement.
Myosin pulls actin, shortening the sarcomere.
ATP resets myosin heads for the next cycle.

Question 10

Slow-Twitch (Type I) Fibers

Answer 10

High endurance, rely on aerobic respiration, found in endurance athletes

Question 11

Fast-Twitch (Type II) Fibers

Answer 11

Fatigue quickly, rely on anaerobic metabolism, used in sprinting and jumping

Question 12

Fish muscle fiber distribution

Answer 12

Red muscle (slow-twitch) for sustained swimming; white muscle (fast-twitch) for bursts of speed

Question 13

Mammal muscle fiber distribution

Answer 13

High slow-twitch in endurance animals (e.g., wolves, horses), high fast-twitch in sprinters (e.g., cheetahs).

Question 14

Bird muscle fiber distribution

Answer 14

High slow-twitch in migratory species, high fast-twitch in short-distance fliers

Question 15

Axial Muscles

Answer 15

Originate from myotomes, involved in posture and trunk movement

Question 16

Appendicular Muscles

Answer 16

Support and move limbs, evolved for terrestrial locomotion

Question 17

Fish muscle function

Answer 17

Myomeres allow lateral undulation for swimming

Question 18

Amphibian muscle function

Answer 18

Limbs adapted for jumping and climbing

Question 19

Reptiles muscle function

Answer 19

Appendicular muscles strengthened for sprawling gait

Question 20

Birds muscle function

Answer 20

Large pectoral muscles for powered flight

Question 21

Mammals muscle function

Answer 21

Specialized limb musculature for running, digging, or climbing

Question 22

Tonic Muscles

Answer 22

Slow, sustained contraction (postural muscles)

Question 23

Phasic Muscles

Answer 23

Rapid contraction and relaxation (movement muscles)

Question 24

Electric Organs in Fish

Answer 24

Modified muscles generate electric fields (e.g., electric eel)

Question 25

Rattlesnake Shaker Muscle

Answer 25

Fast contraction for sound production

Question 26

Bat Wing Muscles

Answer 26

Adapted for rapid wingbeat control