Spermiogenesis Flashcards
Which component of the spermatozoa forms the acrosome?
Golgi apparatus
5 stages of spermatocytogenesis
- Spermatogonia
- Primary spermatocyte
- Secondary spermatocyte
- Spermatid
- Spermatazoa
Describe 4 ways spermatogonia become differentiated
- Nucleus condense
- Mitochondria are spread out in spermatid but lined up along the (forming) tail.
- Tail starts to form with centriole and mitochondria lining up in the first part of the tail (become the mid-piece)
- Residual cells are removed by phagocytosis
Describe the time periods of spermiogenesis
- Spermatogonium to primary spermatocyte (16 days)
- Primary to secondary spermatocyte (24 days)
- Secondary spermatocyte to spermatid (hours)
- Spermatid to spermatozoa (24 days)
- Total 64 days
Which hormones activates Sertoli cells
FSH! and testosterone
5 functions of sertoli cells
- Acts as a blood testes barrier
- Secretes fluid
- Transfers nutrients to keep sperm alive
- Has a role in phagocytosis
- Produces ABP, Inhibin, AMH and oestrogens
What is the importance of the Sertoli cells as a blood-testes barrier?
Provides an immunologically safe microenvironment form sperm using tight junction
What is the importance of the fluid secreted by Sertoli cells?
Moves immobile sperm to epididymus.
What are Sertoli cells roles in phagocytosis?
To remove residual cytoplasm and dead sperm
Which receptors do Sertoli cells express
FSH and androgen receptors
What is the importance of ABP, Inhibin, AMH and oestrogens produced by Sertoli cells?
Androgen-binding protein (ABP) - maintains a high concentration of testosterone in the seminiferous tubules)
Inhibin - inhibits FSH production
Anti-mullerian hormone (AMH) - causes mullein ducts not to develop
Oestrogen - Important for spermatocytogenesis
How long do sperm take to mature and where does this occur?
Approx 1 month in epididymis (here sperm gain ability to be mobile)
Where are mature sperm stored?
Ductus deferens
What is the anatomy of the seminal vesicles?
Posterior to the bladder and drains into the ampulla of the ductus deferent and denotes the beginning of the ejaculatory duct
Function of the seminal vesicle?
Secretes thick, alkaline fluid (which protects sperm from acidic uterine tract) containing fructose, prostaglandins and coagulation factors