Reproductive Physiology Asynchronous Questions

A major function of the epididymis is

A. storage of sperm.

B. initiation of spermatogenesis.

C. secretion of inhibin.

D. de novo synthesis of dihydrotestosterone.

E. de novo synthesis of testosterone.

A. storage of sperm.

Development of the uterus in utero is

A. due to a regression of mullerian ducts.

B. dependent upon anti-mullerian factor.

C. from wolffian ducts.

D. in the absence of testosterone.

E. by default.

D. in the absence of testosterone

Normal development of male external genitalia is

A. dependent upon conversion of testosterone to dihydrotestosterone.

B. independent of 5 α-reductase.

C. independent of androgens.

D. independent of the SRY gene.

E. from Müllerian ducts.

A. dependent upon conversion of testosterone to dihydrotestosterone

The primary source of testosterone in the male is/are

A.Sertoli cells.

B.Sperm.

C.Hypothalamic neurons.

D.Leydig cells.

E.the hypophyseal-anterior pituitary circulation.

D. Leydig cells

What is characteristic of sex hormone-binding globulin?

A. It decreases the half-life of testosterone.

B. It stimulates the secretion of inhibin.

C. It blocks the synthesis of androgen-binding protein.

D. It has a higher affinity for testosterone than it has for estradiol.

E. It reduces the circulating levels of testosterone.

D. It has a higher affinity for testosterone than it has for estradiol

What is the source of estrogen secreted post-ovulation?

A.The corpus luteum.

B.The corpus albicans.

C.The dominant follicle.

D.The endometrium.

E.The oviducts.

A. The corpus luteum

What is a clinical indicator of the onset of menopause?

A. Age 50.

B. Elevated plasma FSH.

C. Breast tenderness.

D. Type II diabetes mellitus.

E. Excessive menstrual bleeding.

B. Elevated plasma FSH

What is involved in the synthesis of estradiol by the Graafian follicle?

A. Synergy between FSH and progesterone.

B. Activation of LH-stimulated granulosa secretion of androgens.

C. FSH stimulated aromatase production by granulosa cells.

D. Inhibition of the preovulatory surge of LH.

E. Decreased secretion of progesterone by the corpus luteum.

C. FSH stimulated aromatase production by granulosa cells

How are the theca interna cells of the Graafian follicle best characterized?

A. They produce androgens from cholesterol.

B. They do not have cholesterol side-chain cleavage enzyme.

C. They aromatize testosterone to estradiol.

D. They secrete inhibin.

E. They are not vascularized.

A. They produce androgens from cholesterol

Actions of testosterone include

A.development of muscle mass in the male during puberty.

B.development of pubic hair in both male and female.

C.masculine behavior.

D.pubertal changes in the voice in males.

E.each of the above.

E. each of the above

Which of the following is insignificant in determining maleness early on?

A.The Y chromosome.

B.Presence of the SRY gene.

C.The formation of Wolffian ducts.

D.Secretion of testosterone

E.XX genotype

E. XX genotype

Blood levels of ____ are indicated by curve B.

A.estradiol

B.estriol

C. progesterone

D.FSH

E. LH

C. progesterone

What is the source for the increase in curve C?

A.Hypothalamus

B.Anterior pituitary

C. Corpus luteum

D. Ovary

E. Adrenal cortex

D. Ovary

What is the cause of the peak shown in curve E?

A. Negative feedback effect of progesterone on the hypothalamus.

B. Negative feedback of estrogen on the anterior pituitary.

C. Negative feedback of FSH on the ovary.

D. Positive feedback of FSH on the ovary.

E. Positive feedback of estrogen on the anterior pituitary.

E. Positive feedback of estrogen on the anterior pituitary

What happens to the corpus luteum if pregnancy takes place?

A.It regresses.

B. It becomes the corpus albicans.

C. It secretes estrogens and progestins.

D.It becomes part of the placenta.

E.It secretes hCG.

C. It secretes estrogens and progestins

What normally prevents fertilization of the ovum by more than one sperm?

A.Polyspermy.

B.The acrosomal reaction.

C.The cortical reaction.

D.Separation of the sperm head from the sperm tail.

E.Presence of the Y chromosome.

C.The cortical reaction

Trophoblast cells during the first three weeks of pregnancy produce ____.

A. estrogen

B. LH

C. oxytocin

D. prolactin

E. hCG

E. hCG

Infertility in the male can be linked to

A.low sperm count.

B.low plasma testosterone levels.

C.too many abnormal sperm.

D.erectile dysfunction.

E.each of the above.

E.each of the above.

Birth control pills containing combinations of synthetic estrogen and progesterone compounds given for the first 21 days of the menstrual cycle are effective in preventing pregnancy. Explain.

A. They prevent the pre-ovulatory surge of LH by the anterior pituitary.

B. They prevent development of the primary ovarian follicles.

C. They suppress the function of the corpus luteum soon after it forms.

D. They prevent normal development of the endometrium.

A. They prevent the pre-ovulatory surge of LH by the anterior pituitary

Menopause is most closely linked to

A. atrophy of the anterior pituitary.

B. reduced responsiveness of the ovarian follicles to gonadotropins.

C. reduced rate of secretion of progesterone by the corpus luteum.

D. reduced number of ovarian follicles.

E. atrophy of the hypothalamic neurons that secrete gonadotropins.

D. reduced number of ovarian follicles

Which of the following hormones is least involved in the synthesis of breast milk?

A.Oxytocin.

B. Prolactin

C.Growth hormone

D.Thyroid hormones

E.Estrogens

A. Oxytocin

What is the primary source of nourishment for the blastocyst during the first week after implantation?

A. Nutrients are present in endometrial secretions.

B. The placenta removes nutrients from maternal blood.

C. The cells of the blastocyst contain stored glycogen.

D. The trophoblast cells digest nutrient-rich endometrial cells and absorb their contents for use by the blastocyst.

E. Invading chorionic vessels absorb nutrients from maternal blood.

D. The trophoblast cells digest nutrient-rich endometrial cells and absorb their contents for use by the blastocyst.

In the circulatory system of the fetus, which of the following is greater before birth than after birth?

A. Left ventricular pressure

B. Right ventricular pressure

C. Arterial PO2

D. Aortic pressure

E. Arterial pH

B. Right ventricular pressure

Which of the following maternal responses to parturition is most correct?

A. Braxton-Hicks contractions are the best indicators of the onset of labor.

B. Elevated blood concentrations of oxytocin block uterine contractions.

C. Uterine receptors for oxytocin decrease in number in the third trimester.

D. Prostaglandins increase the sensitivity of the uterus to pro-contraction agents.

E. The uterus digests the placenta post-partum.

D. Prostaglandins increase the sensitivity of the uterus to pro-contraction agents.

Lactation does not normally occur during pregnancy. Why?

A. Plasma levels of prolactin are too low.

B. Plasma levels of estrogen are too low.

C. Elevated plasma levels of estrogen and progesterone block the actions of prolactin.

D. Plasma levels of oxytocin are too low.

E. Plasma levels of essential pro-lactation hormones are too high.

C. Elevated plasma levels of estrogen and progesterone block the actions