Animal Coordination Flashcards
What are hormones?
Chemical messengers which diffuse into the blood to travel to their target organs where they bring about their effect
What are hormones produced by?
Endocrine glands
What does the pituitary gland produce and what effect does it have?
- growth hormone
- stimulates growth by encouraging mitosis
What does the thyroid gland produce and what effect does it have?
- thyroxine
- controls metabolic rate
What does the adrenal gland produce and what effect does it have?
- adrenaline
- controls fight or flight response
What does the pancreas produce and what effect does it have? (2)
Insulin - lowers blood glucose
Glucagon - increases blood glucose
What do the testes produce and what effect does it have?
- testosterone
- male development during puberty
What do the ovaries produce and what effect do they have?
Oestrogen/progesterone
Female development during puberty
What dk frightening experiences release?
Adrenaline
What are adrenaline’s effects on the body? (4)
- rapid heart beat
- increased blood sugar concentration
- more energy
- increased blood pressure
What can too much/too little glucose do to the body?
Organ damage, fits and can be life threatening
What is the blood glucose concentration like after a meal?
It’s high
What is the blood glucose concentration like after exercise?
It’s low
What monitors blood glucose concentration?
The pancreas
What are the two hormones made by the pancreas which control blood glucose concentration?
Insulin
Glucagon
What is negative feedback
A way your body can control the levels of hormones in the blood using negative feedback systems
Explain the differences between neurones and hormones
Neurones:
- very fast action
- very short time
- precise area
Hormones:
- slower action
- act for a long time
- more general
What are the steps when the thyroxine levels decrease?
- when the thyroxine level is lower than usual, the hypothalamus is stimulated to release TRH
- TRH stimulates the pituitary glands to release TSH
- TSH stimulates the thyroid glands to release thyroxine so the levels return to normal
What happens when the levels of thyroxine increase?
The release of TRH from the hypothalmus is inhibited, reducing the production of TSH, so thyroxine levels fall
What does insulin do when the glucose levels rise?
Insulin causes glucose to change to glycogen which is stored in the liver
What does glucagon do when glucose levels fall?
Glucagon is released, causing glycogen to turn back to glucose
What happens in day 1-4 of the menstrual cycle? (2)
The lining of the uterus breaks down
Low levels of oestrogen and progesterone, egg starts to develop
What happens in day 4-14 of the menstrual cycle? (2)
- lining of uterus builds up and thickens
- oestrogen repairs uterus wall
What happens in day 14-28 of the menstrual cycle? (2)
- Uterus lining stays thick (because of progesterone)
- if egg isn’t fertilised, oestrogen and progesterone levels drop (menstruation)
