Corpus Luteum Flashcards
Luteinization
transformation of follicular cells into luteal tissue
Luteolysis
The process by which luteal tissue undergoes regression and cell death
Be able to describe the classic experiments (involving total/partial hysterectomy) that helped determine the importance of local delivery of PGF2alpha
The experiment involved the result of different hysterectomies and the CL lifespan.
Intact Uterus
normal CL lifespan
Total hysterectomy
CL lifespan equal to gestation length
Contralateral hysterectomy
-removal of uterus on opposite side as CL
-normal CL lifespan
Ipsilateral hysterectomy
-removal of the uterus on the same side as CL
-Longer CL lifespan (>35 days)
Know the actions of progesterone
-Secreted by corpus luteum
-Affects basal LH secretion
-Prevents estrus
-Stops the preovulatory surge of LH
-Reduces myometrial tone: Except in the mare
Know the factors that affect the vigor of the CL
Number of cells and vascularization
Be able to describe the process of luteolysis step by step including the effects of uterine PGF2a on the CL
-Progesterone no longer suppresses formation of uterine oxytocin receptors
-Estradiol binds to endometrial receptors to upregulate oxytocin receptors
-Oxytocin binds to receptors to release PGF2a release
-PGF2a causes CL regression and increase oxytocin released from the CL
Be able to describe how PGF2a is delivered to the ovary/CL.
-PGF2a is delivered to the ipsilateral ovary through a vascular countercurrent exchange mechanism.
-This is crucial as countercurrent exchange of PGF2alpha allows the hormone to be delivered directly to the ovary without much dilution and metabolism from the lungs
Be able to describe why the delivery mechanism is important.
-PGF2a delivered to same-side ovary by countercurrent exchange
-Prevents dilution of hormone
-Prevents metabolism of PGF2a in lungs (circulatory system transport)
