Chapter 10 Spermatogenesis Flashcards
LH last 10-20 minutes 4-8 times per day and targets?
Lyedig cells
FSH occurs in lower concentrations because of inhibin secretion and longer half life but last longer periods. what does FSH target?
Sertoli cells
The leydig cells in males are similar to what in the female?
Theca interna cells of the antral follicles in the ovary
What is the overall goal of spermatogenesis?
Produce sperm
Male GnRH secretion occurs in intermittent, and frequent pulses lasting a few minutes which causes?
FSH and LH
What do Sertoli cells secrete?
inhibin and DHT inhibin (inhibits FSH)
T or F. Leydig cells contain membrane bound receptors of LH
True
T or F. Leydig cells synthesize testosterone upon binding of LH.
False, Progesterone. Progesterone is then converted to testosterone
T of F. Secretion of testosterone from leydig cells is pulsatile
True
What function is a pulsatile release of LH necessary to maintain?
proper testicular function
What happens to LH receptors when there is too much release of LH?
become unresponsive
What happens when LH receptors become unresponsive?
low levels of testosterone production
What are the goals of speratogenesis?
- provide a continuous supply of gametes
2. …
Define Spermatogenesis.
all cell divisions and all morphologic changes that take place within the semineiferous epithelium
Where does spermatogenesis take place?
seminiferous tubles
What changes the developing germ cell?
cell division and morphological changes
What are the 3 phases?
- proliferation phase
- meiotic phase
- Differentiation phase
T or F. developing germ cells are never connected by intercellular bridges
False, all stages are connected by intercellular bridges so the cytoplasm is interconnected
What does the proliferative phase consists of what kind of division?
mitotic divisions of diploid spermatogonia
Where is prorliferative mitotic division take place?
periphery of a seminiferous tubule near the basement membrane and then move to the lumen as they proliferate
Several A- spermatogonia generations go through mitotic divisions to create?
I and then B- spermatogonia
What are the different spermatogonia phases?
A1, A2, A3, A4, I, B
What is an important part of the proliferative phase?
renewal
What is renewal?
the ability for some spermatogonia to revert to stem cells allowing those stem cells to later redevelop into spermatogonia
Stem cells are maintained to ensure continuous spermatogenesis
