Zero to Hero (Module 1) Flashcards
How many eggs would a baby girl be born with?
1 to 2 million eggs
How many eggs would a girl have by the time they reach puberty?
300 thousand eggs
When looking at the layers of the uterus, which layer is muscular and which layer is secretory?
Myometrium is the muscular layer and the endometrium is the secretory layer.
Atresia is
the death of primordial follicles
When the follicle is developing, is the oocyte also growing in diameter. True or False?
True
What are gonadotrophins?
Hormones produced by the Anterior Pituitary gland. For example, FSH and LH.
In folliculogenesis, which follicles are dependant of gonadotrophins for their development, and which are not?
The recruitment and development of primordial follicles into primary follicles does NOT rely on gonadotrophins, it is regulated through local factors such as cytokines. From the secondary follicle onwards development of follicle is dependant on gonadotrophins.
Seminal Vesicle
The organ in males responsible for secretion of 60-70% of total seminal fluid.
Prostate
Seminal fluid 30-40%
Accessory Glands
Seminal vesicle, prostate and bublurethral glands.
Testis: function, development and content
2 functions: production of sperm and hormones.
Develops from posterior abdominal wall. Migrates down into the scrotum in the 7th month of gestation
Has a very tough covering, inside filled in with seminiferous tubules.
Seminiferous tubules
Start and finish at the rete testis. Tough basement membrane, in between = interstitial cells (laydig cells)
Sertoli cells = granulosa cells (in females)
Myoid cells -> muscle cells that help squeeizing sperm out
Sertoli cells
FSH, AMH, ABP, Inhibin
Epididymis
3 regions: caput fluid reabs concentrates sperm, corpus super coiled super long 6m long in humans secretes secretions help with maturing sperm, cauda store sperm for maturation. 20 days for sperm to mature (approx)
Rete testis
Drainage system that drains the fluid from the seminiferous tubules into efferent ducts.
Scrotum
Sac of loose skin that contain the testis. Lots of sweat glands. “Dartos muscles” for contraction.
Pampiniform venous plexus
Important for testicular temperature regulation. It prevents testicles from overheating through the countercurrent heat exchange between arteries bringing warm blood into the testes and veins taking cool blood out.
Gubernaculum
Ligament at the bottom of the testis that connects them to the scrotum
Vas Deferens
Transport (thus muscular) through peristalsis from the epididymis into the urethra.
Seminal Vesicles secrete __________ of the seminal fluid. What exactly is seminal fluid and what does it contain?
60-70% of the seminal fluid.
Seminal fluid is an alkaline secretion that helps to neutralize vaginal acidity and nourish the sperm.
The secretion contains fructose to nourish the sperm, prostaglandins to signal the presence of sperm to the female body, citric acid to regulates pH. It also contains mucus, enzymes, and clotting proteins.
Prostate gland
Depends on DHT (dihydrotestosterone) for growth and development. The enzyme that takes testosterone and makes it into DHT is 5a-reductase.
The prostate gland secretes 30-40% of seminal fluid, containing bicarbonate and citric acid to regulate pH. The secretion also contains proteins, PSA (prostate-specific antigen), which can be used by clinicians as a marker for prostate cancer. PAP is also present, prostate acid phosphatase.
PSA (prostate specific antigen)
Marker for prostate disease (cancer included).
Cowper’s glands = bulbourethral glands
secretes pre-ejaculate, lubricating the glans penis before penetration, also helps in reducing the acidity of the vagina.
Urethra regions
Prostatic: receiving sperm from vas deferens
Membranous: acts as a functional sphincter so that when the male is ejaculating, no ejaculate retrogrades into the bladder
Cavernous: runs the length of the penis.
Penis regions
- Root (base), shaft, glans (head). Consists of erectile tissue and urethra
Erectile tissues
Corpus spongiosum (protective tissue) and around central arteries are the corpora cavernosa (plural).
The erection mechanics
ANS
para -> releases NO -> increases cyclic GMP -> blood flow increases in corpora cavernosa -> veins are compressed -> blood comes in but not out -> erection.
How does Viagra works?
stops breakdown of cyclic GMP
Ejaculation mechanics
sympa -> releases NA -> contraction of vas deferens
Baculum
Bone in the penis (dogs, racoons, walrus have them).
In humans, how long does it take for the maturation of sperm to occur?
3 months all together (testes and epididymis)
The enzyme that converts testosterone into oestrogens
Aromatase
The enzyme that converts testosterone into dihydrotestosterone (DHT)
5a-reductase
The enzyme that converts cholesterol into pregnenolone (which will then become testosterone)
side chain cleavage
What would happen to spermatogenesis after hypophysectomy?
Spermatogenesis would cease, as without the pituitary gland, no LH or FSH is produced, and without LH no testosterone is produced, halting spermatogenesis.
What would happen to a male patient that was immunised against GnRH but received pure FSH?
Without GnRH, LH and FSH would not be produced. Without LH no testosterone is produced, halting spermatogenesis. However, with FSH being introduced ??
Where is PGF2a produced?
In the endometrium
Describe how PGF2a contributes to luteolysis both structurally and functionally.
PGF2a elicits the release of TFN-alpha which prevents blood of getting to the corpus luteum (necrosis).
Stimulates cytokine expression (endothelin-1) disrupting the production of progesterone.
