Paper 2: Section 7- Animal coordination, control and homeostasis Flashcards
What is a hormone?
A chemical messenger produced in glands and carried by the blood to the target organ.
What are glands?
An organ or tissue that makes a substance for release, such as a hormone.
What is a target organ?
The organ with receptor molecules on its cell surfaces which recognise a specific hormone.
What is the pituitary gland and where is it located?
An endocrine gland that is located in the brain and is known as a ‘master gland’. It controlls the water content of the blood.
What hormone does the pituitary gland release? What are the effects?
ADH- Increases reabsorption of water by the collecting ducts.
What is the pituitary glands target organ?
The kidneys
What is the thyroid gland and where is it located?
Gland located at the base of the neck which controls metabolic rate.
What hormone does the thyroid gland release? What are the effects?
Thyroxine
- Controls the body’s metabolism
- Plays an important role in growth and development
What is negative feedback?
A mechanism where changes to conditions cause an action to reverse the change, to keep conditions stable.
What is the negative feedback mechanism?
Mechanism to lower raised levels of something, and to raise reduced levels of something.
Low thyroxine levels in the bloodstream stimulate the ____________ to release T_H, causing the pituitary to release ___. This way the thyroid releases more thyroxine and _____ levels return to normal. When thyroxine levels are normal thyroxine _______ the release of TRH and the _________ of TSH.
- hypothalamus
- R
- TSH
- blood
- inhibits
- production
What is the pancrease and where is it located?
Large gland located in the abdomen which controlls blood glucose levels.
What hormone does the pancrease release? What are the effects?
Insulin- Increases the conversion of glucose into glycogen for storage.
What is the pancreases target organ?
The liver.
What are the adrenal glands and where are they located?
Glands located on top of the kidneys which prepare for ‘fight or flight’.
What hormone do the adrenal glands release? What are the effects?
Adrenaline (prapers for flight and flight)
- Increases the breathing and heart rate
- Increases flow of blood to muscles
- Converts glycogen to glucose
What are the adrenal glands target organs?
Several targets including organs in the respiratory and circulatory systems.