The Endocrine System Flashcards
What is the endocrine system?
The body’s slower but more long-lasting communication system.
How does the endocrine system compare to the nervous system?
It acts more slowly but has more powerful and widespread effects.
What makes up the endocrine system?
A number of glands around the body.
What do glands in the endocrine system do?
Release hormones into the blood to regulate the activity of organs and tissues.
Why do hormones only affect certain cells even though they travel throughout the blood?
Only target cells have the correct receptor sites for the hormone.
What happens if a cell does not have the right shaped receptor for a hormone?
It cannot be affected by the hormone.
What causes a physiological reaction in a target cell?
When enough receptor sites are stimulated by the hormone.
What role does the hypothalamus play in hormone regulation?
It regulates hormone levels in the blood.
What happens when a hormone level is too low in the blood?
The hypothalamus sends a releasing hormone to the pituitary gland.
What does the pituitary gland do when it recieves a releasing hormone?
It releases a stimulating hormone into the blood targeting a specific gland.
What does the target gland do in response to the stimulating hormone?
It releases the hormone that was previously low.
What is negative feedback in hormone regulation?
When the hypothalamus senses hormone levels are high enough, it stops sending messages, ending the cycle.
Where are the testes located?
The genitals.
What do the testes secrete?
Testosterone.
What is the function of testosterone?
Linked to aggression.
Where are the ovaries located?
The pelvis.
What do the ovaries secrete?
Progesterone and oestrogen.
What is the function of progesterone and oestrogen?
Regulates the female menstrual cycle.
Where are the adrenal glands located?
Above the kidneys.
What does the adrenal gland secrete?
Adrenaline.
What is the function of adrenaline?
Initiates a fight or flight response.
