Spermatogenesis and fertilisation Flashcards
Is phase 4 of spermatogenesis more or less rapid than oogenesis
More rapid
Where does spermatogenesis begin?
Seminiferous tubules of testers after puberty
What are type A spermatogonia?
mitotically active throughout reproductive life
How are spermatogonia kept at edge of semiferous epithelium?
Interlocking sertoli cells connected by intercellular cytoplasmic bridges
What are type B spermatogonia termed as when they enter meiosis
Primary spermatocytes
How long do spermatocytes take to complete meiosis 1
24 days
What happens during meiosis 1
spend this time making mRNA for later protein production
What is the result of early translation into protein
Sterility
What is produced from meiosis 1
Secondary spermatocytes
What is produced from meiosis 2
Spermatids
How are spermatids converted to spermatozoa
Spermiogenesis
How does spermatid changes as it becomes spermatozoa
- Reduction in nuclear size
- Golgi apparatus condense
- Flagellum grows from centriole
- Cytoplasm streams away from nucleus
- Mitochondria in spiral arrangement around flagellum
- Head partitioned into domains
What is the final step of sperm maturation
Capacitation
Where does capacitation occur
Female genital tract (requires contact with secretions of the oviduct)
What does LH stimulate
Testosterone production by Leydig cells