Spermatogenesis Part 2 Flashcards
What must spherical spermatids do?
- Must condense nuclear DNA (grows tail)
- Form a cell that become motile for ertilization
During the Goligi phase (spermatid) what occurs?
- initial acrosome formation
- Initial tail development, translocation of centrioles
*Proximal ceontriol
*Distal centriol
What is a proximal centriol? What is a Distal centriol?
- Attachment point of tail (flagellum)
- Central portion of tail or axoneme (tail fibres)
What occurs during the cap phase?
- Acrosomic vesicle flattents and “caps” the nucleus
- Primitive tail grows from distal centriole
- Acrosome membrane formed (outer and inner)
- Production of hydrolyic enzymes (Acrosinm hyaluronidase, zona lysin, esterases, acid)
What occurs in Acrosome reaction ?
- Exocytosis during fertilization
- Digest zona pellucida
What occurs in the Acrosomal phase?
- Acrosome covers 2/3 nucleus, nucleus elongates
- Manchette microtubules form: become postnuclear cap
- Neck & annulus formation
What is an Annulus?
Junction between midpiece & principle piece
What occurs in the maturation phase (The final sperm assembly (FSH dependent))?
- Spermatid becomes a spermatozoon
- Mitonchondria surround mid-piece in helical fashion
- Completion of tail
- Spermiation
What does the completion of tail consist of?
- Mid-piece
- Principal piece
- Terminal piece
What is Spermiation?
The release of sperm from sertoli cells into the lumen of the seminiferous tubules
What is necessary to transcript? What is necessary to translate?
- Needs chromosomes
- Needs ribosomes
What can the spermatozoon do?
- Sperm chromatin are compacted and condensed
- DNA is protected by disulfide bonds
- Sperm do not transcribe or translate protein
What does the ultrastructure of sperm consist of?
- Head
- Midpiece
- Principle Piece (tail)
What attaches the head to the tail? What gives the neck flexibility? Metabolic power plant is what piece?
- Capitulum
- Laminated columns
- Mitochondrial helix
How is the arrangement of the principle piece?
- Unique fiber arrangement (9+9+2) contract/release to create movement
* 2 central fivrils through all tail pieces
* 9 double fibrils through mid and principal pieces
* 9 course outer fibers mid piece only
How does the testis produce sperm on a continual basis?
Through the cycle of the seminiferous epithelium
What are the layers of skin of the scrotum?
- Scrotal skin
- Tunica dartos
- Scrotal fascia
- Pariental vaginal tunic
- Visceral vaginal tunic