Ch 11: The Musculoskeletal System (Kaplan)

Question 1

Much like hemoglobin, myoglobin uses ____ to carry oxygen; it is not however housed within a red blood cell. Thus, an erythrocyte – free urine sample that tests positive for heme points compellingly toward rhabdomyolysis.

Answer 1

heme

p. 397

Question 2

Muscles also contain myoglobin, which binds oxygen with high ________. As exercising muscles run out of oxygen, they use myoglobin reserves to keep aerobic metabolism going.

Answer 2

affinity

p. 408

Question 3

Why are type I slow twitch fibers also called red oxidative fibers?

Answer 3

Because of their high myoglobin content. They also have a much better blood supply than fast twitch fibers, due to an extensive surrounding capillary network.

p. 418

Question 4

Type I slow twitch fibers may be slow, and generate low force, but they have _____ mitochondria, ____ _____ capillary networks, and are highly resistant to _______.

Answer 4

many
very dense
fatigue

p. 419

Question 5

What is the difference between type IIA and IIB fast twitch fibers?

Answer 5

Type IIA have more mitochondria than IIB and are, thus, more resistant to fatigue.

p. 418

Question 6

What are type IIA muscle fibers also known as?

Answer 6

intermediate or “fast twitch oxidative” fibers