Please enable JavaScript.
Coggle requires JavaScript to display documents.
Reproductive Cyclicity: Luteal Phase - Coggle Diagram
Reproductive Cyclicity: Luteal Phase
Luteinization: Phase 1
Formation of CL
Transformation of follicular cells into luteal cells after ovulation
Controlled by LH
Thecal cells = small luteal cells
Steroidogenic = progesterone
Hyperplasia
Increase in number
Granulosal cells = large luteal cells
Oxytocin in CL of cycle
Relaxin in CL of pregnancy
Steroidogenic = progesterone
Hypertrophy
Increase in size
Synthesis and secretion: Phase 2
Growth and development of CL
Large quantities of progesterone
Uterus
Glandular endometrium
Muscular myometrium
Mammary glands
Hypothalamus
Negative feedback
Inhibitor
Prevents behavioral estrus
Stops the preovulatory LH surge
Reduces GnRH pulse frequency
Reduces myometrial tone
Poor progesterone = insufficient luteal function
Reproductive failure
LH and cholesterol must be present
Luteolysis: Phase 3
Destruction of CL
Decrease in blood progesterone
Loss of luteal tissue mass
Induced by PGF2a
Secreted by uterine endometrium
Vascular countercurrent exchange mechanism
Requirements
Oxytocin receptors on endometrial cells
Critical level of oxytocin
PGF2a synthesis by endometrium
Local vasoconstriction
Initiates menstruation
Results
Structural regression to form corpus albicans
Removal of negative feedback by progesterone
Results in new follicular phase
Cessation of progesterone secretion
CL
Preovulatory follicle
Corpus hemorrhagicum
Many small blood vessels rupture, clot forms
Follicle collapses into folds
Functional CL
Mixture of small and large luteal cells
Basement membrane deteriorates
Granulosal cells and theca interna cells intermingle
Vigor
Number of luteal cells
Degree which CL becomes vascularized
Synthesize and deliver hormones
Formation
