The Endocrine System
- Created by: Rolloh04
- Created on: 03-02-20 21:45
View mindmap
- The Endocrine System
- Negative feedback systems
- Hormone production is often controlled by centres in the brain by the mechanism of negative feedback
- If there's rise in hormone levels this will be detected by the control centre in the brain and it would reduce hormone production
- If there's a drop in hormone levels the control centre in the brain will detect this and increase hormone production
- Thyroxine
- Thyroxine is produced in the thyroid gland which is controlled by the pituitary gland
- regulates metabolism
- 1) When the level of thyroxine drops, the pituitary gland produces thyroid stimulating hormone (TSH)
- 2) TSH stimulates the thyroid gland to produce thyroxine
- 3) increasing levels of thyroxine will cause the production of TSH to decrease them.
- The endocrine system basics
- Hormones are chemical messengers produced in glands
- They're released directly into the blood and travel to target organ
- The cells in the target organ contain receptors to which the hormone can bind
- Adrenaline
- The 'fight or flight' hormone
- produced in response to exercise, anxiety or fear
- produced by adrenal gland
- Adrenaline increases heart and breathing rates, increases the rate of blood supply to the muscles and raises blood glucose levels in preparation to fight or flight
- Menstrual cycle
- oestrogen causes build-up of the uterus wall
- Progesterone- maintains lining of the womb
- Follicle stimulating hormone- FSH- stimulates release of an egg because it stimulates the overaries t produce oestrogen
- 1) on the 0-7 the day the uterus lining breaks down (a period)
- 2) on the 7-13th day the repair of the uterus wall takes place. oestrogen causes the uterus lining to gradually thicken
- 3) on the 14th day the egg is released by the overary
- 4) on the 15-21st day progesterone and oestrogen make the lining stay thick, waiting for a fertalised egg
- 5) if there is no fertalised egg on the 28th day the cycle starts again
- 4) on the 15-21st day progesterone and oestrogen make the lining stay thick, waiting for a fertalised egg
- 3) on the 14th day the egg is released by the overary
- 2) on the 7-13th day the repair of the uterus wall takes place. oestrogen causes the uterus lining to gradually thicken
- Main hormone producing glands
- Pituitary Gland
- LH- involved in reproduction
- FSH- follicle stimulating hormone- involved in reproduction
- ADH- Controls water content in blood
- Growth Hormone- stimulates growth
- Thyroid gland
- Thyroxine- controls metabolism
- Pancreas
- Insulin- controls blood glucose levels
- Glucagon- controls blood glucose levels
- Adrenal
- Adrenaline- fight or flight
- Ovaries
- oestrogen- reproduction and secondary sexual characteristics
- Progesterone- reproduction and secondary sexual characteristics
- Testes
- Testosterone- secondary sexual characteristics
- Pituitary Gland
- Pituitary Gland
- often called the 'master gland' because it controls several other glands
- It produces TSH, which acts on the thyroid gland
- It also produces adrenocorticotrophic (ACTH) which acts upon the adrenal gland
- Negative feedback systems
Comments
No comments have yet been made