Please enable JavaScript.
Coggle requires JavaScript to display documents.
Hormones, homeostasis and reproduction
(VI. 6) - Coggle Diagram
Hormones, homeostasis and reproduction
(VI. 6)
-
Hormones
Leptin
If adipose tissue increases, blood leptin concentrations rise, causing appetite inhibition
-
-
Melatonin
-
-
It depends on two groups of cells in the hypothalamus called the suprachiasmatic nuclei (SCN). They control melatonin secrection in the pineal gland
-
-
A ganglion cell in the retina of the eye detects light (460–480 nm) and passes impulses to cells in the SCN
Thyroxin
Threfore, thyroxin regulates metabolic rate and controls body temperature
Hypothyroidism results in: fatugue, depression, weight gain, feeling cold, constipation, brain underdevelopment in children
Higher metabolic rates cause body heat, therefore cooling triggers the secretion of thyroxin (body temperature rises)
Most cells in the body are affected by thyroxin, since it regulates metabolic rates
-
-
-
Menstrual cycle
-
If fertilisation doesn't occur, the corpus luteum and the endometrium break down, causing menstruation
The endometrium is repaired and thickens, the
most developed follicle releases its egg into the oviduct
In the first half of the cycle (follicular phase) a group of follicles is developing in the ovary, in each follicle an egg is stimulated to grow
Hormones
Estrogen peaks towards the end of the follicular phase. It stimulates the thickening of the endometrium and an increase in FSH receptors (more estogen production)
LH peaks towards the end of the follicular phase, it stimulates the completion of meiosis in the oocyte and partial digestion of the follicle (causes it to burst)
FSH peaks towards the end of the cycle and stimulates the development of follicles, it also stimulates secretion of estrogen by the follicle wall
When it reaches high levels, estrogen inhibits the release of FSH and increases that of FH
Estrogen and progesterone are ovarian hormones, produced by the wall of the follicle and corpus luteum
-
FH and FSH are protein hormones released by the pituitary gland that bind to receptors in the membranes of follicle cells
Progesterone levels rise at the start of the luteal phase, peak and then drop back to a low level by the end of this phase. It promotes thickening and maintainance of the endometrium. It also inhibits FSH and FH production