ZO 315 -- COMPARATIVE ANATOMY

EXAM 2

1. The attachment of muscles to bones by way of tendons is significant in the function of the
musculoskeletal system. Describe four (4) ways in which tendons are functionally significant. [12 pts.]

2. Why is it so difficult to discern trends in the evolution of the vertebrate muscular system? How can homologies be determined? [10 pts.]

3. What advantage does the single circulatory circuit of gill-breathing fishes have over the circulatory
systems of amphibians and reptiles? [5 pts.]

4. In what way are the branchiomeric muscles of fishes and tetrapods functionally alike? In what ways
are they different? [8 pts.]

5. Early in vertebrate evolution, the arrangement of capillary in series was the driving force behind what evolutionary change in the heart? In tetrapods, what other major evolutionary trend do we see in the
anatomy of the heart? What selective pressure led to this other major anatomical change? [10 pts.]

6. The aortic arches are one of the best anatomical features for establishing the phylogeny of the
vertebrates. In terms of the fates of the pairs of arches, what features are shared by all jawed
vertebrates? Which arch(es) has a common fate in all tetrapods? In general, what are the fates
of arches 4 and 6? [15 pts.]

7. Why is it unlikely that fishes might have evolved respiratory structures like lungs, into which water
would have been drawn for extraction of O2, followed by expulsion back to the outside of the
animal? [5 pts.]

8. Tell me how 5 of the following 6 pairs of terms are related. Don't just give me definitions. You
may answer the 6th pair for extra credit, but be sure to mark the bonus answer "EC". [4 pts. each]

a) liver // pancreas:

b) aponeurosis // tendon:

c) hepatic portal system // renal portal system:

d) muscle fiber orientation // force:

e) ductus arteriosus // foramen of Panizza:

f) fish scales // reptile scales:

9. FUNCTIONAL SIGNIFICANCE: State the functional significance of 5 of the following 6 items. You
may answer the 6th item for extra credit, but be sure to indicate which one is to be graded as the
extra-credit question by writing "EC" next to it. [3 pts. each]

a) stratum corneum:

b) tongue:

c) salivary glands:

d) smooth muscle in walls of arterioles:

e) sphincter muscles:

f) spiral fold in conus arteriosus of amphibians: