Female Hormones and Menstrual Cycle

Functions of oestrogen - ovaries

Follicular growth and ovum maturation

Functions of oestrogen - uterus

endometrial growth and glandular development

Functions of oestrogen - uterus and oviduct

Muscle contractions facilitating sperm transport

Functions of oestrogen - cervix

Mucus-clear, thin and watery to facilitate sperm penetration

Functions of oestrogen - breasts

Duct growth and fat deposition

Functions of oestrogen - brain

mood enhancement and neuroprotection

Functions of oestrogen - sodium retention

Water retention and weight gain

Functions of progesterone - uterus

Endometrium maintenance and secretion from uterine glands

Functions of progesterone - cervix

Mucus - thick and sticky to plus cervix and prevent bacteria entry

Functions of progesterone - breasts

Alveolar development

Functions of progesterone - brain

Alleviates depression and reduces anxiety

Functions of progesterone - body temp

Increases basal body temperature

Menstrual cycle overview

lasts from first day of period to first day of next period, average 25-30 days but varies 

Follicular phase

Includes menstruation phase lasting 2-5 days corresponding to shedding of stratum functionalis of endometrium

Follicular phase step 1

Constriction of spiral arteries which reduces blood flow to areas of endometrium, secretory glands in functional zone begin to deteriorate due to oxygen and nutrient deprivation

Follicular phase step 2

Weakened arterial walls rupture = blood pours into connective tissues of functional zone, blood cells and degenerating tissues break away and enter uterine cavity which are lost as they pass through vagina and externally

Follicular phase - ovaries

Maturation of follicles and rising of oestrogen levels

Ovulation

Day 14 of cycle, rising levels of oestrogen stimulate surge of LH release - positive feedback, causes follicle rupture and released oocyte from ovary into oviduct, may or may not be fertilised

Luteal phase

Ruptured follicle forms corpus luteum, releases large amounts of progesterone and some oestrogen

Corpus luteum secretions

Essential for establishing and maintaining pregnancy in uterus

Luteal phase step 2

If egg not fertilised or implanted, corpus luteum degenerates into corpus albicans approx 10 days after ovulation = decreased oestrogen and progesterone levels = fsh and lh no longer inhibited by negative feedback

Luteal phase step 3

Increase of progesterone levels stimulates uterine glands to secrete uterine milk at uterine level - high in protein and glycogen, arteries that supply uterine wall elongate and spiral through tissues of functional zone or stratum functionalis 

Luteal phase step 4

Secretory phase begins at time of ovulation and persists as long as corpus luteum remains intact

Luteal phase step 5

Degeneration of corpus luteum occurs if there is no fertilisation - stratum functionalis cannot be maintained, necrosis occurs, layer of uterus expelled with blood as menstrual fluid