Hormones Flashcards
What is homeostasis?
The maintainance of a constant internal environment within set limits.
What is a hormone?
A chemical substance produced by a gland and carried by the blood. It alters the activity of one or more specific target organs.
What is adrenaline?
A hormone that chemically controls metabolic activity. It increases blood glucose concentration
What are the effects of adrenaline?
It increases breathing rate, pulse rate and widens the pupils.
Where is insulin secreted from?
The pancreas
What is the function of insulin?
Decreases blood glucose concentration
Where does adrenaline come from?
Adrenal glands
When is adrenaline secreted?
In ‘fight or flight’ situations, such as when the body is in danger
How does adrenaline control metabolic activity?
It chemically controls metabolic activity, including increasing the blood glucose concentration and pulse rate
Name of the glands that secrete hormones
Endocrine glands
Hormone secreted from ovaries
Oestrogen
Hormone secreted from testes
Testosterone
Function of oestrogen
Develops secondary sexual characteristics in females
Function of testosterone
Develops secondary sexual characteristics in males
Difference between the speed of nervous and hormonal control systems
Nervous control systems are fast, while hormonal control systems are slow
Difference between the longevity of nervous and hormonal control systems
Short longevity for nervous, greater longevity for hormonal
How are signals transferred in nervous control systems
Through electrical impulses
Negative feedback
A mechanism used in homeostasis, in which when a change in a parameter brings about actions that push it back towards normal
Why does adrenaline increase blood glucose concentration?
Because of the increased respiration in muscle cells
Why does adrenaline increase pulse rate and breathing rate?
So glucose and oxygen can be delivered to muscle cells and carbon dioxide can be taken away as quickly as possible
Why does adrenaline dilate the pupils?
To allow as much light as possible to reach the retina so more information can be sent to the brain
Why is blood flow diverted towards muscles and away from non essential parts like the alimentary canal?
To provide glucose and oxygen for respiration