Spermatogenesis and male tract Flashcards
What cells are found in early testis
Spermatogonia, sertoli cells, leydig cells, myoid cells
What hormones cause descent of the testis
AMH and testosterone
Where does meiosis 1 occur in males
At the junctional complex
When do leydig cells begin to create testosterone
8-10 weeks
List anatomical features of testis
Seminiferous tubules, rete testis, efferent ducts, head, body, tail of epidymis, ductus deferens, vas deferens
Where are the sertoli cells found
Seminiferous tubules, from the basement membrane
Where are the leydig cells found and what do they produce
Outside seminiferous tubules (interstitial space). Testosterone
What does the junctional complex do
Separates the spermatagonia and spermatocytes which have different chromosomal numbers. Distinguishes the basal and luminal compartments.
What does a spermatagonia become as it goes through the junctional complex
Primary Spermatocoyte
How many chromosome do primary spermatocytes have
2n
How many chromonsomes do secondary spermatoctyes have and what do they become
1n spermatids
What are the four phases of spermiogenesis
Golgi, cap, acrosomal, maturation
Transit time from basal lamina to lumen
74 days
What is normal ejaculate sperm count and what is considered sub fertile
50-100 million per mL. Less than 15 million per mL
Does the testis need the pituitary and vice versa
Yes. LH stimulates the leydig cells to produce testosterone (bHCG in early weeks). Sperm and testosterone provide negative feedback on pituitary to regulate LH and FSH release.
What cells produce inhibin and what does it do
Sertoli cells, negative feedback on FSH release
What is the negative feedback on LH
Testosterone
What cells convert testosterone to oestrogen and what feedback does oestrogen have on the hypothalamus
Sertoli cells via aromatase (and fatty tissue). Negative feedback on GnRH
Where is ABP produced and what does it do
Binds testosterone/ andorgens for transport. Sertoli cells
What is the important steroid for seminiferous tubules, epidydimis, prostate, seminal vesicles
DHT. Testosterone converted to DHT in leydig and sertoli cells via 5 alpha reductase
What is the physiology of an erection
Sensory input to erection centre (L1), causes relaxation of smooth muscle in corpus cavernosa, obstructs venous outflow, relaxation due to NO, stimulated by guanine monophosphate
What breaks down guanine monophosphate and thus stops an erection
phosphodiesterase-5
Analysis of semen infertility (5)
Count, motility, morphology, volume, liquification
What is the essential function of T/DHT in spermatogenesis
Meiosis, spermatid maturation, stimulation of ABP
