male reproductive system

in the superficial fascia of the scrotum

• tunica vaginalis (outer layer from peritoneum)
• tunica albugnea (inner, dense fibrous capsule that folds in to divide testis

abdominal aorta

• testicular veins arise from
• surrounds each testicular artery to cool artery going to the testes

from abdominal to inguinal canal (development as ligament that gets pulled down)

cryptorchidism

• sperm can't be produced b/c the temperature is too warm. 
• prepenile: outside the ouside layer (tunica vaginalis)

in the seminiferous tubles; thick, stratified epithelium surrounding central fluid-containing lumen

myoid cells

• nurse cells that support spermatogenesis
• interstitial endocrine cells that produce androgens (secrete hormones)

spermatocytes to spermatids to spermatozoa

• production of sperm in the seminiferous tubles
• begins at puberty
• each division produces a daughter cell that is pushed toward the lumen of the tuble

• spermatogonia (stem cells) in contact with epithelial basal lamina
• each mitotic division yields one type A and one type B daughter cell (primary spermatocyte)
• meiosis I and II

primary spermatocyte (2n) goes to form secondary spermatocyte (n)

secondary spermatocyte (n) forms two spermatids (small, nonmotile cells close to lumen of the tuble

• final stage in sperm production
• spermatids elongate; lose excess cytoplasm, form a tail, become spermatozoon

• head (genetic region) nucleus and helmet like acrosome (contains hydrolytic enzymes that enable sperm to penetrate egg)
• midpiece: metabolic region; mitochondra which gives ATP to move tail
• tail

tight junctions divide tubule into two compartments, prevent sperm from getting into the blood

• provide nutrients and signals to dividing cells
• move cells along to lumen
• secrete testicular fluid into lumen for sperm transport
• phagocytize germ cells and excess cytoplasm
• make sure sperms don't get out of the testes and into blood (body would amount immune response otherwise)

straight tubule then the rete testis then the efferent ductules then epididymis

• where sperm is stored, the beginning of the male reproductive tract
• supply nutrients to the spermatoza
• takes two weeks for the sperm to travel through, after which they are physically mature (learned to swim)
• ajusts fluid produced by seminiferous tubules with microvilli
• contracts to produce ejaculation, expelling sperm to ductus deferens

micorvilli absorb testicular fluid (establish concentration inside tubule) and pass nutrients to stored sperm

ductus deferens, ejaculatory duct, urethra

vas deferens passes through inguinal canal to pelvic cavity, which joins duct of seminal vesicle

• seminal gland
• prostate gland
• bulbo-urethral glands

• contributes 60-70% of the semen fluid
• constricts like vas deferens and epididymis to ensure fluid gets into uretha as well
• prostaglandins stimulate smooth muscle to help sperm move up the reproductive tract
• fibrinogen forms semen clot in vagina
• slightly alkalin to buffer acid environments
• provide fluid that initiates capacitation (development of motility)

• secretes milky, slightly acidic fluid (20-30% of semen volume)
• seminalplasmin: antibiotic properties, appears to help prevent UTIs

sperm is forced up into the vas deferens, which goes up, around the front of, over the top of, and behind the bladder

interferes with urination by constricting the urethra

produce thick, clear mucus during sexual arousal to lubricate penis and neutralize traces of acidic urine in uretha

• root (bulbo-urethral gland)
• body
• glans

spongy network of connetive tissue and smooth muscle with vascular spaces

• corpus spongiosum: surrounds urethra and expands to form glans and bulbs
• corpora cavernosa: paired dorsal erectile bodies

arterial branches of corpus spongiosum constricted, little blood flow

• parasympathetic neurons release NO, a vasodilator
• causes vascular smooth muslce relaxation
• arterioles dilate, corpora cavernose expand, blocks venous drainage
• engorgment of erectile tissues with blood (enlargement and stiffening of the penis)

• a sympathetic spinal reflex where ducts, bulbospongiosus muscles and accessory glands contract and empoty their contents
• bladder sphincter muscle constricts, preventing expulsion of urine

• too little NO from parasympathetic stimulation (alcohols, drugs)
• incompetent venous valves

• regulates production of gametes and sex hormones through 3 interacting sets of hormones
• GnRH indirectly stimulates testes via FSH and LH
• FSH and LH direcly stimulates testes

targets nurse cells to trigger spermatogenesis

• causes interstitial cells to secrete testosterone
• testosterone and inhibin (negative feedback on hypothalamus and anterior pituitary)