Unit 3 Quiz Review

decreased secretion of testosterone.

Changes called male climacteric are a consequence of

cholesterol; acrosomal enzymes

Prior to ejaculation, __________ in the sperm plasma membrane prevents premature release of ______________.

a deformity of the limbs.

A teratogen is most likely to cause

corpus luteum; estrogen and progesterone

After expelling the oocyte, the follicle becomes the ____________ and secretes __________.

the bulbospongiosus muscle.

All of the following play a role in thermoregulation of the testes except

gametes; germ cells

As a result of spermatogenesis and spermiogenesis, the final cells produced are called ____________, but they and all the stages leading up to them can be called ____________.

spermatid

At what stage does a developing sperm cell begin to grow a tail?

all of the organ systems are present.

By the end of 8 weeks, the individual is considered a fetus because

cytotrophoblast; syncytiotrophoblast

During implantation, the trophoblast divides into a deep layer, the _________, composed of individual cells, and a superficial layer, the ___________, composed of a multinucleate mass of cytoplasm.

estradiol; LH

During the follicular phase, granulosa cells secrete ____________, which stimulates secretion of ___________.

human chorionic gonadotropin

In early pregnancy, ____________ stimulates growth of the corpus luteum.

ductus venosus; ductus arteriosus

In fetal circulation, the __________ bypasses the liver and the _________ bypasses the lungs.

Na+; prevents the entrance of any more sperm

In the fast block to polyspermy, binding of sperm opens up _________ channels, which depolarizes the egg membrane and _________.

spermatids; spermatozoa

In the process of spermiogenesis, ___________ become ___________.

nipple and areola; oxytocin

Milk ejection occurs as a result of stimulation of nerve endings in the ____________ , which leads to the release of ______________ from the pituitary.

These are relatively gene-poor chromosomes.

Only autosomal trisomies involving chromosomes 13, 18, and 21 are survivable. Why would this be?

umbilical vein

Oxygenated blood reaches the fetus through the

antigen-presenting cells and helper T cells.

Senescence of the immune system makes older people more subject to cancer and infectious disease because of a decline in

inhibiting degradation of cGMP.

Sildenafil (Viagra) prolongs erection by

blastocyst; embryo; fetus

The developing individual is called a(n) ___________ during most of the first 2 weeks, a(n) _____________ from 3 through 8 weeks, and a(n) ____________ from the beginning of week 9 until birth.

estriol; estradiol

The most abundant estrogen of pregnancy is __________, but the one that accounts for most of the estrogenic effects in pregnancy is ______________.

The blood-testis barrier

prevents antibodies in the blood from getting to the germ cells.

progesterone acts

primarily in the uterus

inhibin

Which hormone suppresses spermatogenesis without affecting testosterone secretion?

progesterone

Which of these blood hormone levels reaches its maximum during the luteal phase?

Estradiol and progesterone; FSH and LH

____________ inhibit/s the secretion of ____________ during the female sexual cycle.

Luteinizing hormone (LH); testosterone

_____________ stimulates the interstitial cells of the testes to secrete __________.

testosterone

________________ stimulates the descent of the testes.