01.2 Origins of the Gametes Flashcards
When does spermatogenesis begin?
Puberty
When does oogenesis begin?
In the foetus
What is the rate of spermatogenesis against oogenesis?
Spermatogenesis - 200mil daily
Oogenesis - 1 Ovum per 28 days
How many spermatids are produced for every one primary spermatocyte?
4
How many ova are produced for every one primary oocyte?
1 Ovum
3 Polar Bodies
How long does gametogenesis continue for?
Males - Until Death
Females - Until menopause
Where does meiosis 2 occur during oogenesis to form the ovum?
In the fallopian tube upon fertilisation
What is the path that sperm travel along?
Seminiferous Tubules, Rete Testis, Ductus Efferentes, Epididymis, Vas Deferens
Define Spermatogenic Cycle
Time taken for reappearance of the same stage within a given segment of the tubule (16 days)
Define Spermatogenic Wave
Distance in space between the same stage (as the waves move forward like a corkscrew)
Define Spermiation
Where spermatids are released into the lumen of the seminiferous tubules
Define Spermiogenesis
The final stage of spermatogenesis where spermatids mature into spermatozoa
What is capacitation of sperm?
Where the female genital tract stimulates :
Removal of glycoproteins and cholesterol from sperm
Activation of sperm signalling pathways
Allowing sperm to bind to zona pellucida and initiate the acrosome reaction
What significance does the capacitation reaction have on sperm used for IVF?
Sperm must be incubated in capacitation media as fertilisation occurs outside of the female genital tract
What are the three main stages that an oocyte develops through?
Preantral
Antral
Preovulatory
What is the antrum?
Fluid filled space between the granulosa cells
How many follicles reach maturity?
Usually only 1
What causes the follicle to develop into the preovulatory stage?
LH surge
This causes meiosis 1 to complete
At what stage in Meiosis 2 does the oocyte arrest in until fertilisation?
Metaphase
What is the corpus luteum?
The remaining cells after ovulation
These produce the hormones oestrogen and progesterone and die if no fertilisation occurs
What does the corpus luteum become after dieing?
Corpus Albicans
