Sperm and their Origins Flashcards
What is the head/cap of the sperm called?
Acrosome
What lies posterior to the acrosome of sperm?
Nucleus
Where is the mitochondria located in the sperm?
Midpiece
Fetal gonad forms from a bipotential primordia. How does it occur in males?
The medulla develops into a testis and the cortex degenerates
Fetal gonad forms from a bipotential primordia. How does it occur in females?
The cortex develops into an ovary and the medulla degenerates
Why can male gametes increase in number postnatally?
Because they arrested at mitosis and can resume again
What are the two types in cells in the Seminifeous tubules?
Sertioli cells
Leydig cells
What is the role of the Sertoli cells?
Nourishment of the spermatozoa
Which set of cells form of the Blood-Testis barrier?
Myoid cells
What are Myoid cells?
A set of cells which form the Blood-Testis barrier
What is the sperm stem cell called?
Spermatogonium
Describe the change in chromosome number during Spermatogenesis
- Begins diploid (2n)
- Replicates DNA (2n to 4n)
- Chiasma forms
- Cells divide to yield 2 x 2n
- No second round of DNA replication
- Cells divide from 2n to 1n
1 Sperm stem cell can make how many Type A1 Spermatogonium?
16
16 Type A1 Spermatogonium can make how many Type B cells?
32 Type B
32 Type B cells can make how many resting primary spermatocytes?
64
The primary spermatocyte is diploid or haploid?
Diploid
The secondary spermatocyte is diploid or haploid?
Haploid
What are the four sub cell types in Spermatogenesis?
SpermatoGOnia
SpermaTOcytes
SperMAtids
SpermaTOZoa
(Go to ma toz)
What is the role of LH in males?
Acts on the Leydig cells to produce Testosterone (4 - 10 mg)
Testosterone acts on the hypothalamus in a negative feedback loop to reduce LH synthesis
What is the principle Androgen hormone in males?
Testosterone
What is the role of FSH in males?
FSH binds to receptors on Sertoli cells, and stimulates production of Androgen receptors
What is the potent form of Testosterone, and how is it converted from Testosterone?
5-alpha DHT, via reductase
What is the male equivalent of Theca cells?
Leydig cells
What is the male equivalent of Granulosa cells?
Sertoli cells
What receptor does the Leydig cells have?
LH receptor
What receptor does the Sertoli cells have?
FSH receptor
How much sperm is the normal range per ml?
15 million per ml
What is the name given to “low sperm count”?
Oligospermia
What is the name given to “complete absence of semen”
Aspermia
What is the name given to the “complete absence of sperm”
Azoospermia
What is the name given to “low motility of sperm”
Asthenozoospermia
What is the erectile tissue of the penis?
Corpora cavernosa
What is the mechanism of action of Sildenafil?
PDE5 inhibition
