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.