Topic 7 - Animal Coordination, Control And Homeostasis Flashcards
Hormone
Chemical messengers sent in the blood to a target organ
What produces hormones
Endocrine Glands
Pituitary Gland
Release hormones that act on other glands, referred to as the ‘master gland’
Thyroid Gland
Thyroxine produced which regulates: Metabolism, heart rate and temperature
Ovaries
Oestrogen
Testes
Produce Testosterone controlling puberty and sperm production
Adrenal Gland
Adrenaline
Creates a ‘fight or flight response’
Pancreas
Produce insulin and glucagon regulating glucose
Hormones and Neurones
Neurones:
Fast action
Short duration
Precise areas
Hormones:
Slow Action
Long duration
General areas
Adrenaline
From Adrenal Gland (above kidney)after brain spots a hazard.
- Binds to heart receptors increasing heart rate, increasing blood flow so it receives more glucose and oxygen for respiration.
- Binds to liver receptors breaking down glycogen to glucose,
Negative feedback
Hormones are regulated, if it exceeds its specified amount a response will occur to bring it back to normal.
Metabolism
The rate chemical reactions occur
Thyroxine homeostasis
TOO LOW:
Hypothalamus releases TRH.
TRH stimulates Pituitary to release TSH
TSH stimulates Thyroid to release Thyroxine (and rises)
TOO HIGH:
TRH Inhibited (therefore TSH) reducing production of Thyroxine
TRH
Thyrotropin Releasing Hormone
TSH
Thyroxine Releasing Hormone
Menstruation Cycle 4 stages
Stage 1: Day 1:
Lining on Uterus breaks down and released.
Stage 2: Day 4 - 14:
Uterus lining builds up. For the arrival of the egg.
Stage 3:
Egg develops and released. (OVULATION day 14)
Stage 4: Day 14-28
Lining is maintained until no fertilised egg lands by Day 28.