Female Reproductive Endocrinology and reproductive cycle Flashcards
From which molecule are steroid hormones synthesised from?
Cholesterol
Where are steroid hormones mainly produced?
Adrenal glands
Gonads
Placenta
Why is it important that steroid hormone receptors have a high affinity and specificity to their substrates?
Steroid hormones are present in low concentrations in serum and tissues
Where in the cell does steroid hormone production primarily occur?
Smooth ER and mitochondria
Steroid hormones are stored. T/F?
False
What is the intermediary in the synthesis of progesterone from cholesterol?
Pregenolone
What symptoms may result from a deficiency of 21-hydroxylase or 11beta- hydroxylase?
Ambiguous genitalia
Precocious ouberty
Anovulation
Hirsutism
What eefct will aromatase excess have in a male?
Conversion of androgens to oestrogens resulting in feminisation of male genetalia
What types of hormones are GnRH, FSH and LH?
Peptide hormones
Where is GnRH secreted from?
Hypothalamus
Where are FSH and LH secreted from?
Anterior pituitary gland
What are the three phases of the ovarian cycle and at what days in the female reproductive cycle do these occur?
Follicular phase days 1-13
Ovulation day 14
Luteal phase days 15-28
What are the three phases of the uterine cycle and at what days in the female reproductive cycle do these occur?
Menstruation days one to five
Proliferative phase days 6 to 14
Secretory phase days 15 to 28
At the start of the female reproductive cycle, progesterone and oestrogen levels are low. Why is this significant?
This stimulates GnRH release from the hypothalamus which stimulates the gradual release of LH and FSH from the anterior pituitary which stimulates follicle growth and development
How does the developing follicle in the ovary produce oestrogen?
The theca cells are stimulated to produce androgens by LH and the granulosa cells pick up these androgens and convert them via aromatase to oestrogens under the influence of FSH