chapter 9 - muscular system; part 3

Question 1

what is incomplete and complete tetanus?

Answer 1

it is partial relaxation between contractions; complete tetanus is no relaxation between contractions

Question 2

what is muscle tone?

Answer 2

it is the maintenance of steady tension for long periods

Question 3

isometric contractions

Answer 3

cause a change in muscle tension but no change in muscle length

Question 4

isotonic contractions

Answer 4

causes a change in muscle length but no change in muscle tension

Question 5

concentric contractions

Answer 5

causes muscles to shorten an tension to increase

Question 6

eccentric contractions

Answer 6

causes muscles to lengthen and tension to decrease gradually

Question 7

asynchronous contractions

Answer 7

these produce smooth, steady muscle contractions

Question 8

what are slow twitch muscle fibers?

Answer 8

these are muscle fibers split ATP slowly and have a well-developed blood supply, many mitochondria, and myoglobin; long distance runners have a higher percentage of slow twitch fibers

Question 9

what do fast twitch fibers split?

Answer 9

they split ATP at a rapid rate; sprinters have a greater percentage of fast-twitch fibers

Question 10

type 2a fast twitch fibers

Answer 10

have a well-developed blood supply, more mitochondria, and more myoglobin

Question 11

type 2b fast twitch fibers

Answer 11

have large amounts of glycogen, a poor blood supply, fewer mitochondria, and little myoglobin

Question 12

what are some effects of exercise on muscles?

Answer 12

muscle increase (hypertrophy) or decrease (atrophy) in size because of a change in the size of muscle fibers; anaerobic exercise develops type 2b fibers; Aerobic exercise develops type 1 fibers and changes type 2b fibers into type 2a fast-twitch fibers

Question 13

what is heat a by-product of?

Answer 13

it is a by-product of chemical reactions in muscles; shivering produces heat to maintain body temperature