Spetmatogenesis Flashcards
What is spermatogenesis?
The process whereby spermatozoa are formed. It consists of proliferation (mitosis), meiosis and differentiation.
How long does spermatogenesis take?
Spermatogenesis requires 5 to 9 weeks
depending on the species.
Where does spermatogenesis take place?
Spermatogenesis takes place in the
seminiferous tubules.
What are the three stages of spermatogenesis?
Proliferation by mitosis:
— Mitotic divisions of spermatogonia
— Ultimately a large number of B spermatogonia
are produced
Meiosis
— During meiosis we have crossing over which
ensures genetic heterogeneity
— Haploid spermatids produced
Differentiation
— Formation of cell capable of fertilisation
Which sperm development types are associated with proliferation?
Spermatogonia a,b and I
Which sperm developmental types are associated with meiosis?
Primary and secondary spermatocytes
Which sperm developmental types are associated with Differentiation?
secondary spermatocytes and spermatids.
During development what kind of structure do sperm have?
A syncytium.
What germ cell has the longest lifespan in relation to spermatogenesis?
Primary spermatocyte.
What are the different phases of differentiation?
— Golgi phase
— Cap phase
— Acrosomal phase
— Maturation phase
What does the acrosome contain?
Acrosome contains hydrolytic enzymes required for
penetration of zona pellucida (shell of oocyte)
What hormones are responsible for spermatogenesis?
GnRH secretion from hypothalamus
FSH and LH from the anterior pituitary
Testosterone and oestrogen from gonad
What is the pituitary a slave to?
The hypothalamus
What is the gonad a slave to?
The pituitary.
What does LH do?
— Binds to receptors on Leydig cells
— Leydig cells produce testosterone
