Biology 317/319                       Endocrinology                    Exam III                      [Date B]


Instructions: There are 100 points on this exam; 85 on objective and 15 on essays. The exam has 6 pages and 11 questions. Budget your time and good luck.

1. (15 points, 3 each) Define the following terms with respect to their use in endocrinology.

a) Capacitation

b) Cortical Reaction

c) Gonadostat theory

d) Goiter

e) Fertile period

2. (12 points) Fill in the table.

Genetic Gonadal Internal External

Phenotype Phenotype Reproductive Reproductive

_________ _________ Phenotype Phenotype


[XX] [Ovary] [Normal ] [Normal ]

XX, SRY+, HY+,


XY, SRY+, HY+,


XY, androgen Rec-

XX, 21-Hydroxylase-

3. (16 points) Classify the listed compounds by placing the capital letter in front of the name of the compound onto the line for the compound class.

a) Androgens____________________________

b) Estrogens_____________________________

c) Progestagens__________________________

d) Glucocorticoids_________________________

A) Aldosterone B) Androstenedione C) Cholesterol D) Cortisol

E) Cortisone F) Dehydroepiandrosterone G) 5-Dihydrotestosterone H) Estradiol

I) Estriol J) Estrone K) Hydrocortisone L) Pregnenolone

M) Prednisolone N) Progesterone O) RU486 P) Testosterone

4. Matching. (15 points, 1 point per response). Indicate which item in the answer list best matches the description in the list of questions; write the appropriate letter in the blank. There is only one correct answer per question but each response may be used either more than once or not at all.

____ a) Myometrial cells and myoepithelial cell both contract in response to

____ b) Site of capacitation of sperm

____ c) The major estrogen of pregnancy

____ d) A primary mechanism for preventing polyspermy

____ e) Destined to become the fetus

____ f) Stores sperm prior to ejaculation

____ g) Formation is stimulated by LH after ovulation

____ h) Structure within which the ovum develops prior to ovulation

____ i) The isthmus, ampulla, and ostium are all parts

____ j) That which maintains differentiation of endometrium

____ m) Protein precursor of thyroxine and triiodothyronine

____ n) Structure surrounding the developing oocyte and zygote until nidation

____ o) Hormone responsible for decalcification of pelvic bone and ligaments prior to parturition

____ p) Small glands embedded in thyroid tissues that force thyroid removal to affect multiple endocrine systems

____ q) Structure in which milk is produced and stored in most species

A. Cortical reaction B. Zona pellucida C. Estradiol D. Testosterone

E. TBG F. Corpus luteum G. Acrosome H. Estriol

I. Seminal vesicles J. Fallopian tube K. Alveoli L. Thyroglobulin

M. Capacitation N. Progesterone O. Cervix P. Epididymus

Q. Relaxin R. Trophoblast S. Polar body T. LH

U. Myoepithelium V. Tail of sperm W. Fimbria X. Oxytocin

Y. Syncytiotrophoblast Z. Norepinephrine AA. Prostate gland BB. Follicle CC. Inner cell mass DD. Vagina EE. Parathyroids FF. Ampullary

GG. Midpiece of sperm HH. Uterus II. Gland cistern JJ. Counter-current exchange

5. The following steroidogenic enzymes catalyze irreversible reactions.

a) 45 Isomerase

b) 18-hydroxylase

c) 3-hydroxysteroid dehydrogenase (oxoreductase)

d) C20,22 lyase

e) Acyl-CoA:cholesterol acyltransferase

6. The number of primary oocytes in most female mammals

a) decrease continually throughout their reproductive lifespans.

b) are continually replenished during adulthood by meiotic division of oogonia.

c) reach a peak prior to birth.

d) is only slightly larger than the number ovulated during the entire reproductive span.

e) is roughly equal to the total number of sperm generated by a male during his lifetime.

f) become depleted at about the time of menopause

g) is sensitive to gonadotropin levels in the fetus during gestation

7. Lipoprotein complexes:

a) are differentiated in the laboratory on the basis of lipid composition

b) are differentiated at the target cell on the basis of lipid composition

c) are differentiated in the laboratory on the basis of apoprotein composition

d) are differentiated at the target cell on the basis of apoprotein composition

e) are differentiated in the laboratory on the basis of density

8. Progesterone

a) exerts a strong inhibitory influence on the uterine myometrium

b) inhibits the formation of -lactalbumin and thereby lactose

c) promotes duct development in the breasts

d) is primarily responsible for development and maintenance of female secondary sex characteristics

e) can only act in many instances after estrogen has stimulated progesterone receptor formation

9. The physiology of "maternal recognition of pregnancy" involves

a) speeding up the process termed luteolysis.

b) termination of negative feedback of progesterone on LHRH production.

c) trophoblastic assumption of hormonal support for function of the corpus luteum.

d) both chorionic gonadotropin and prostaglandins.

e) breast engorgement.

Essay Question (15 points; answer 1 of numbers 10 or 11).

10. Over the past decade tremendous strides have been made in the development of techniques that can be used to increase fertility in humans and domestic species. Among the various procedures now available are: GIFT (gamete intraFallopian tube transfer) in which several hundred or thousand sperm are injected into the recipient's Fallopian tubes just before the anticipated time of ovulation; SUZI (subzonal injection) in which a small number (1-20) sperm are injected inside the zona pellucida of an isolated egg and then incubated in vitro prior to transfer to the recipient's uterus; and ICSI (intracellular sperm injection) in which a single sperm is injected into an isolated egg, incubated in vitro, and then transfered to the recipient's uterus. Given what you know about the process of fertilization and development, suggest what some of the major risks might be, especially to the pregnancy and/or offspring, in ICSI and SUZI that would be absent or minimal with GIFT.

11. Rabbits, cats, ferrets and a variety of other mammalian species exhibit the phenomenon of induced (reflex) ovulation. In this phenomenon intercourse stimulates a surge release of LHRH and LH via a neuroendocrine reflex arc. Since in the nonpregnant animal there is always a crop of preovulatory follicles this normally causes ovulation shortly following intercourse. Given what you know of spontaneous ovulation as it occurs in humans and many other non-reflex species, what are the advantages or disadvantages of an animal using reflex ovulation as a reproductive strategy?