524- Male reproductive system Flashcards
What is the testes?
Location? Why?
1) the male gonads
2) hangs outside the abdominopelvic cavity, posterior to the penis
- sperm production sensitivity (3*C cooler than normal body temp, cuz it’s too hot!)
What is the spermatic cord?
a connective tissue sheath housing nerves, blood vessels, lymphatics for each testis and vas deferens.
How does the scrotum respond to temperature changes?
> Dartos muscle: wrinkled skin of scrotum (decreases heat loss)
> Cremaster muscle: pulls testes closer to torso (increases temp)
What are the 2 layers surrounding the testes?
> Tunica Vaginalis:
extension of peritoneum
> Tunica Albuginea:
deeper, whiter, fibrous capsule of testis
1) How does the lobules, seminiferous tubules, rete testis and epididymis relate to each other?
2) What is Leydig (interstitial) cells? (explain)
1) lobules are extensions of the tunica albuginea which divide the testis into (about) 250 wedge shaped lobules. Each contains 1-4 tightly coiled, sperm producing seminiferous tubules.
The sperm are moved to the rete testis and then into the epididymis where it develops the ability to swim.
2) cells that make testosterone.
- found in the connective tissue surrounding the seminiferous tubules, they make TESTOSTERONE. It is then secreted into the interstitial fluid of the testis, not into the s. tubules where it can then diffuse into the blood.
How does negative feedback apply to the male r. system?
GnRH from hypothalamus tells the a. pituitary gland to secrete FSH and LH.
- FSH causes the development of spermatozoa (sperm cells) in the testes + secrete inhibin (hormone) from testes.
- LH causes the testes to secrete testosterone.
High levels of these hormones (detected by hypothalamus +a. pituitary) inhibits further secretion of GnRH + FSH + LH, which consequently decreases secretion of testosterone and inhibin.
1) What are the 3 long cylinders of erectile tissue in the penis called?
2) What is erectile tissue?
1) Corpora Cavernosa:
2 superior
Corpus Spongiosum:
1 inferior, surrounds urethra
2) a spongy network of connective tissue, smooth muscle and vascular spaces.
What does the duct system consist of?
> Epididymis: become motile (20 days to move through this) 6m long ducts
Vas deferens: epididymis to ejaculatory duct which empties into the urethra within the prostate gland.
Urethra: transport semen (ejaculation) and urine out
1) What does the Accessory glands consist of?
2) What does it do?
1)
>Seminal vesicles-
smooth muscle layer that contracts during ejaculation to secrete its stuff into the ejaculatory duct.
>Prostate-
surrounds urethra. smooth muscle wall contracts causing its secretions to enter the urethra
>Bulbourethral glands-
2) produce seminal fluid
What do the seminal vesicles make?
yellow, viscous fluid (70% of semen volume)
- has stuff that provide nutrition for the sperm, coagulate semen, enhance sperm motility and fertilising ability
What does the prostate gland’s secretion do?
provide nutrition + contains enzymes that activate the sperm (1/3 of the semen volume)
1) What is the bulbourethral glands secretion made up of?
2) What does it do?
1) thick, clear mucus secreted into the urethra
2) clears out of urine just before ejaculation.
1) What is semen?
2) What is it made up of?
1) milky, white viscous fluid
2) seminal fluid
sperm
What is the sperm cell (spermatozoa) made up of?
functions?
> Head:
flat nucleus (has DNA)
Acrosome:
sac covering the head, breaks down outer coating of oocyte when released to facilitate fertilisation.
Midpiece:
contains mitochondria that provide ATP for tail’s movement
Tail:
single flagellum, propels itself through whip-like motions
Is the seminal fluid acidic or alkaline? Why?
Alkaline to neutralise vagina’s acidic environment. Sperm gets sluggish when it enters pH below 6.
