Structure and Function of Male Genitourinary System Flashcards
promotes the conversion of embryonic glands to testes in utero
testis-determining factor
cells secrete testosterone beginning at the 8th week, masculinizes embryonic structures, and then hibernate until puberty
Leydig
Testes develop in abdominal cavity and descend through what to get to pouch of peritoneum (tunica vaginalis)?
inguinal canal
Causes wrinkles on scrotum
dartos muscle
Responsible for elevating the scrotum
cremaster muscle
site of sperm production. lead into efferent ducts
seminiferous tubules
What do efferent ducts emerge to form and is also the final site of sperm maturation?
epididymis
serves as a storage reservoir for sperm
ampulla of the vas deferens
Secretion of what hormone inhibits anterior pituitary release of FSH
inhibin
What hormone inhibits LH and GnRH production?
testosterone
Contain receptor proteins for FSH in Sertoli cells
seminiferous tubules
LH stimulates secretion of testosterone. Contain receptor proteins for LH
leydig cells
When are the leydig cells fully mature?
10yrs
Embryonically the determining factor in the development of male or female genital organs and characteristics
testosterone
If the Leydig cells aren’t mature till after the age of 10, how does this differentiation occur?
HCG from mother stimulates testosterone secretion in the fetal testes
If a male child is born with undescended testicles, what can be used to cause testes to descend in usual manner?
testosterone or LH
Both ovarian and testicular tissue is present in the body
intersex
Most common cause of female pseudohemaphroditism
congenital adrenal hyperplasia
mature for two months until they become spermatozoa
spermatids
Actually envelope spermatids for processing before release into lumen (protect and nurse sperm)
Sertoli cells
divide in two stages, one of which is by the process of meiosis to form four spermatids, each containing 23 unpaired chromosomes
spermatocytes
Four main functions of sertoli cells
form blood-testes barrier, secrete inhibin and androgen-binding protein, phagocytize residual bodies
Where do sperm become fully motile and go through final maturation?
epididymis
Regulates conversion of spermatogonia into spermatocytes
FSH
secrete mucoid material containing fructose, citric acid, prostaglandins, and fibrinogen
seminal vesicle
fluid from vas deferens, seminal vesicles, prostate gland, as well as the bulbourethral glands and glands throughout the urethra
semen
Average sperm count for ejaculate
400 million
Each ductus deferens is cut and tied. Interferes with sperm transport
vasectomy
Where are the most important sensory nerve signals located of male reproductive system?
glans penis
caused by parasympathetic impulses from sacral portion of spinal cord to penis. dilates arteries of the penis leading to high pressure flow into erectile tissue
erection
Emission and ejaculation are dependent on what nervous system?
sympathetic
relax the muscles around the urethra in men with symptoms from an enlarged prostate. Urine then flows more freely
alpha blockers
These medications reduce the level of a certain form of testosterone (DHT). The prostate shrinks when less DHT is present, improving urine flow
5-alpha-reductase inhibitors
Smooth muscle in the urinary bladder innervated by parasympathetic fibers responsible for involuntary contraction
detrusor muscle
skeletal muscle WHICH IS under voluntary control. This can be used to consciously prevent urination even when involuntary controls are attempting to empty the bladder
external sphincter
smooth muscle INVOLUNTARILY CONTROLLED with natural tone, and therefore prevents emptying of the bladder until the pressure in the main part of the bladder rises above a critical threshold
internal sphincter
Drug class that is used to treat overactive bladder due to muscles contracting at the wrong time
anticholinergics
