Production of Sperm Flashcards
Where does sperm production occur?
In seminiferous tubules
Simply explain the anatomical path of sperm
Seminiferous Tubules
Mediastinum
Head of epididymis
Tail of epididymis
Ductus Deferens
What cells are responsible for production of testosterone?
Leydig
3 type of Germ cells?
Spermatogonia
Spermatocytes
Spermatids
3 types of somatic cells
Leydig
Sertoli
Myoid and non-myoid cells
What do leydig cells produce?
Testosterone
What do sertoli cells produce?
Lactate
Inhibin
What makes up the blood testis barrier?
Sertoli-sertoli cell tight junction
Myoid cell layer
What cells are always located at the basal lamina and in basal compartments?
Spermatogonium (2n)
Nomenclature process of spermatogenesis
Spermatogonium (2n)
Primary Spermatocyte (2n)
Secondary Spermatocyte (n)
Spermatid (n)
Spermatozoon
3 stages of cell differentiation
Spermatocytogenesis
Spermatidogenesis (meiosis)
Spermiogenesis
Durring spermatocytogenesis, what occurs to self-renewal ability?
Decreases as multiplation occurs
What is one of the most critical and important stages of haploid cell production?
Metaphase I
How many haploid cells can one spermatocyte generate?
4
What does estrogen support during spermiogenesis
Estrogen will also support the condensation of the DNA of the spermatids during the spermiogenesis
What is spermiation?
Removal of residual cytoplasm from the spermatid by the sertoli cell, formation of the proximal droplet and release into the tubule lumen
What is a sign of immaturity?
Residual cytoplasm
How many discharges of GnRH in the male occur/day
4-6
With regulation of spermatogenesis what occurs to GnRH when DHT, E2 and T are high
GnRH will be low due to negative feedback
If you are testing tesosterone levels in a male, is one sample a day enough?
No, need to do 4-6 due to different discharges of GnRH each day
Efficiency of spermatogenesis?
Not very efficient, hard to actually generate the possible 256 cells due to a lot that can go wrong
Phenotypes observed when disruption of the spermatogonia proliferation occurs
Infertility
Very low testis weight
“Gelly” (smooshy) like texture
No mature spermatozoa observed in ejaculate
Phenotypes observed when disruption of meiosis occurs
Infertility
Low testis weight
Gelly like texture
No mature spermatozoa oberved in the ejaculate, only round cells
Phenotypes observed when disruption of spermiogenesis occurs
Infertility or subfertiliyt
Similar or smaller testis weight
Mature spermatozoa observed in ejaculate but at low concentration
High ratio of abnormal spermatozoa in the ejaculate
How does blood cool down before entering testis
Blood from body runs through artery and is cooled by blood returning from testis to body
Where does final maturation of sperm occur?
Epididymis
What occurs to activity of sperm when in the tail of epididymis?
Activity is reduced due to a slightly acidic envirionment of 6.8. This reduces movement of sperm to reduce irritation as well as waste of energy
What do sperm in the head of the epididymis lack?
Sperm do not have the factors important for motility and fertilization processes
