Hormones, Homeostasis and IVF Flashcards
What is a hormone?
A chemical substance that controls processes in the body.
What is homeostasis?
The maintenance of a constant internal environment.
What 4 things need to be controlled in order to maintain the constant internal environment?
- Water content in the body
- Ion (salt) content in the body
- Temperature of the body
- Blood sugar levels
How does water content get controlled?
Water loss from:
- The lungs when we exhale
- The skin through sweating
- Passing urine produced by the kidneys
Why does water have to be controlled?
To protect cells from too much water entering the cells or too much water leaving them.
How is ion content in the body controlled?
The loss of ions from:
- The skin through sweating
- Passing urine produced in the kidneys
Why is temperature controlled in the body?
To maintain the temperature at which the enzymes in the body work best.
How is body temperature controlled?
- Sweating
- Shivering
- Controlling blood flow to the skin
Why are blood sugar levels controlled?
To provide cells with a constant supply of energy.
How are blood sugar levels controlled?
By the release and storage of glucose- controlled by insulin.
What are the hormones in the menstrual cycle and where are they produced?
- FSH- produced in pituitary gland
- Oestrogen- produced in the ovaries
- LH- produced in the pituitary glands
What does FSH do?
- Causes an egg to mature in an ovary.
- Stimulates the ovaries to release oestrogen.
What does oestrogen do?
- Stops FSH being produced so only one egg is matured in a cycle.
- Stimulates the pituitary gland to release LH.
What does LH do?
- Triggers the release of the mature egg from the ovary (ovulation)
What does IVF stand for?
In vitro fertilisation.
