Homeostasis and Response Flashcards
Explain how negative feedback helps to maintain a stable internal environment.
When the level of something (eg water or glucose) gets too high or too low , the body uses negative feedback to get it back to normal.
What makes up the central nervous system and what does it do?
The brain and spinal cord.
It receives information from receptors and then coordinates a response.
What is a synapse?
The connection between two neurones.
What is the purpose of a reflex action?
To prevent injury by reacting as quick as possible.
Give two differences between nervous and hormonal responses.
Nervous - very fast action, acts for a very short time and on a very precise area.
Hormonal - Slower action, acts for a long time and in a more general way.
What effect does the hormone glucagon have on blood glucose level?
Increases blood sugar level.
Describe two effects of FSH on the body.
Causes an egg to mature in the ovaries.
Stimulates the ovaries to produce oestrogen.
Which of the following is a hormonal contraceptive - condom, plastic IUD or diaphragm?
Plastic IUD (releases progesterone)
Describe how IVF is carried out.
Eggs are collected from the ovaries and are fertilised outside of the body (in a lab) with sperm.
The fertilised eggs are grown into embryos in an incubator.
Once they’re grown into tiny balls of cells, 1 or 2 of them are transferred to the womb.
How does adrenaline prepare the body of “fight or flight”?
It triggers mechanisms that increase the supply of oxygen and glucose to cells in the brain and muscles.
