MALE REPRO
Wednesday, 11 September 2024
4:55 PM
A- detrusor muscle
B- right ureter
C- trigone
D- urethra
MALE REPRO
Spermatogonium (46):
Male germ cell
Always in contact with the seminiferous tubule basement membrane
Primary spermatocyte (46/diploid):
Product of mitotic division of spermatogonium
Divides via meiosis I
Secondary spermatocyte (23):
divides via meiosis II
Spermatid:
Differentiates into sperm cells through spermiogenesis
Formed from second meiotic division
In contact with the luminal membrane of seminiferous tubule while it undergoes differentiation
Spermatozoa/zoon:
Head, midpiece and tail
Within lumen
Dartos muscle: Thin layer of muscle in connective tissue surrounding the scrotum; responsible for skin of scrotum becoming wrinkled and reducing surface area
Cremaster Muscle: An extension of the abdominal muscles into the scrotum; pulls the testes closer to the body when outside temp drops.
An erection occurs due to the activation of the parasympathetic nervous system. This causes vasodilation of the penile arteries as a result of smooth muscle relaxation in their tunica media. Increased blood flow in the arteries results in an engorgement of the corpora cavernosa and the corpus spongiosum due to an increase in the blood volume within their sinusoids.
The pampiniform plexus is a network of 10 - 12 veins which surround the testicular artery. This forms a counter-current heat exchange system so that warm blood in arteries leaving the body heat cooler blood in the veins leaving the testes. The arterial blood entering the testis is now less than 370C. The pampiniform plexus works with the dartos and cremaster muscles to
thermoregulate the testes and keep them at a constant cooler temperature than body temperature.
Hormones
GnRH
Origin: hypothalamus
Target: anterior pituitary
FSH
Origin: anterior pituitary
Target: sustentacular/Sertoli cells of seminiferous tubules
Stimulates production of androgen binding protein (ABP)
LH
Origin: anterior pituitary
Targets: interstitial/Leydig cells
Stimulates production of testosterone
Testosterone
Stimulates spermatogenesis
Increases metabolism
Regulates secondary sexual characteristics
ABP
Binds to testosterone
Increases testosterone levels
Origin: sertoli cells
Inhibin
Inhibits the release of GnRH and FSH
Released when sperm count is high
Origin: Sertoli cells
Glands (makes up 95% of seminal fluid, other 5% from sperm)
Bulbourethral gland (Cowper's):
5% of semen
Produces an alkaline mucus = lubricant and neutralises pH in the urethra during intercourse
Seminal vesicles
60% of semen
Produces fructose, other nutrients and citric acid to nourish sperm
Produces fibrinogen (fibrin) = semen coagulation (stickiness)
Produces prostaglandins = uterine contractions to transport sperm
Prostate gland
30% of semen
Produces fibrinolysin to dissolve coagulated sperm
Contains seminal plasmin = antimicrobial
Average volume of ejaculation = 2-5mL
spermatogenesis vs Spermiogenesis
spermatogenesis : the entire process which forms spermatozoa
Spermiogenesis: the differentiation of a spermatid to form a spermatozoon is Correct
The section of the urethra which travels through the penis is called: spongy urethra
Path of sperm to the vas deferens:
Seminiferous tubules
Straight tubules (tubulus rectus)
Rete testis
Efferent ductules
Head of epididymis
Body of epididymis
Tail of epididymis
Vas deferens
Why do spermatogonia divide into 'A' and 'B' cells?
A replenishes stem cell pool, B becomes primary spermatocyte
What branches of the nervous system stimulate emission/ejaculation and erection?
Erection: parasympathetic
Emission: sympathetic
What is the name of the thickened layer of white fibrous tissue surrounding the corpora cavernosa; and its role? Tunica albuginea. Allows compression of veins during erection
Wednesday, 11 September 2024
4:55 PM
A- detrusor muscle
B- right ureter
C- trigone
D- urethra
MALE REPRO
Spermatogonium (46):
Male germ cell
Always in contact with the seminiferous tubule basement membrane
Primary spermatocyte (46/diploid):
Product of mitotic division of spermatogonium
Divides via meiosis I
Secondary spermatocyte (23):
divides via meiosis II
Spermatid:
Differentiates into sperm cells through spermiogenesis
Formed from second meiotic division
In contact with the luminal membrane of seminiferous tubule while it undergoes differentiation
Spermatozoa/zoon:
Head, midpiece and tail
Within lumen
Dartos muscle: Thin layer of muscle in connective tissue surrounding the scrotum; responsible for skin of scrotum becoming wrinkled and reducing surface area
Cremaster Muscle: An extension of the abdominal muscles into the scrotum; pulls the testes closer to the body when outside temp drops.
An erection occurs due to the activation of the parasympathetic nervous system. This causes vasodilation of the penile arteries as a result of smooth muscle relaxation in their tunica media. Increased blood flow in the arteries results in an engorgement of the corpora cavernosa and the corpus spongiosum due to an increase in the blood volume within their sinusoids.
The pampiniform plexus is a network of 10 - 12 veins which surround the testicular artery. This forms a counter-current heat exchange system so that warm blood in arteries leaving the body heat cooler blood in the veins leaving the testes. The arterial blood entering the testis is now less than 370C. The pampiniform plexus works with the dartos and cremaster muscles to
thermoregulate the testes and keep them at a constant cooler temperature than body temperature.
Hormones
GnRH
Origin: hypothalamus
Target: anterior pituitary
FSH
Origin: anterior pituitary
Target: sustentacular/Sertoli cells of seminiferous tubules
Stimulates production of androgen binding protein (ABP)
LH
Origin: anterior pituitary
Targets: interstitial/Leydig cells
Stimulates production of testosterone
Testosterone
Stimulates spermatogenesis
Increases metabolism
Regulates secondary sexual characteristics
ABP
Binds to testosterone
Increases testosterone levels
Origin: sertoli cells
Inhibin
Inhibits the release of GnRH and FSH
Released when sperm count is high
Origin: Sertoli cells
Glands (makes up 95% of seminal fluid, other 5% from sperm)
Bulbourethral gland (Cowper's):
5% of semen
Produces an alkaline mucus = lubricant and neutralises pH in the urethra during intercourse
Seminal vesicles
60% of semen
Produces fructose, other nutrients and citric acid to nourish sperm
Produces fibrinogen (fibrin) = semen coagulation (stickiness)
Produces prostaglandins = uterine contractions to transport sperm
Prostate gland
30% of semen
Produces fibrinolysin to dissolve coagulated sperm
Contains seminal plasmin = antimicrobial
Average volume of ejaculation = 2-5mL
spermatogenesis vs Spermiogenesis
spermatogenesis : the entire process which forms spermatozoa
Spermiogenesis: the differentiation of a spermatid to form a spermatozoon is Correct
The section of the urethra which travels through the penis is called: spongy urethra
Path of sperm to the vas deferens:
Seminiferous tubules
Straight tubules (tubulus rectus)
Rete testis
Efferent ductules
Head of epididymis
Body of epididymis
Tail of epididymis
Vas deferens
Why do spermatogonia divide into 'A' and 'B' cells?
A replenishes stem cell pool, B becomes primary spermatocyte
What branches of the nervous system stimulate emission/ejaculation and erection?
Erection: parasympathetic
Emission: sympathetic
What is the name of the thickened layer of white fibrous tissue surrounding the corpora cavernosa; and its role? Tunica albuginea. Allows compression of veins during erection