HPA axis and menstrual cycle Flashcards
What is the term used for the formation of gametes in the ovaries?
Oogenesis
Describe how oogonia are formed?
During early foetal development, primordial germ cells migrate from the yolk sac to the ovaries where they differentiate into oogonia which are diploid (2n)
What do some oogonia develop into if they do not degenerate?
Primary oocytes
What occurs to the primary oocytes during puberty?
- several primordial follicles are stimulates each month
- brings a secondary oocyte with a tertiary follicle to the point of ovulation where meiosis 1 is completed (haploid n)
What occurs at ovulation?
The tertiary follicle ruptures to expel the secondary oocyte into the pelvic cavity
What is the corpus luteum?
- development of the mature graafian follicle in the ovary
- temporary structure essential for establishing and maintaining pregnancy in females
- degenerates after 2 weeks
Which hormone is produced by the corpus luteum?
Progesterone
Which structures make up the HPA axis?
Hypothalamus
Pituitary glands
Adrenal glands
What are the embryological regions from which the anterior and posterior pituitary develop from?
Anterior = upgrowth from the mouth = Rathke's pouch Posterior = down growth from the hypothalamus
What is the role of the infundibulum?
Stalk that connects the pituitary to the brain
Which hormones are secreted by the posterior pituitary?
ADH and Oxytocin
- only released not synthesised
Describe the portal system in the anterior pituitary
The hypothalamic hormones reach the anterior pituitary through a specialised circulatory system.
Neurohormones from the hypothalamus control release of anterior pituitary hormones
What are the 6 hormones produced by the anterior pituitary? (FLAT PiG)
F = FSH L = LH A = ACTH T = TSH P = Prolactin G = GH
Which lobe of the pituitary is the intermediate lobe embryologically the same as?
Anterior = up growth from the mouth
What is released from the intermediate lobe of the pituitary?
MSH = melanin skin pigment
