Homeostasis Flashcards
What does homeostasis mean?
Keeping your internal environment constant.
What 5 things does homeostasis include monitoring and controlling?
- Waste materials.
- Body temperature.
- Water content
- Ion content.
- Blood glucose levels.
What 2 waste materials have to be removed from the body?
- Carbon dioxide.
2. Urea.
How is carbon dioxide produced?
By respiration.
How is carbon dioxide removed from the body?
Via the lungs when we breathe out.
How is urea produced?
In the liver by the breakdown of amino acids.
How is urea removed from the body?
By the kidneys. It is temporarily stored in the bladder and then excreted as urine.
What temperature should the body be kept constant at?
37^oC
What 3 things does the thermoregulatory centre in the brain do?
- Monitors and controls body temperature.
- Has receptors that monitor the temperature of the blood flowing through the brain.
- Receives information (impulses) from temperature receptors in the skin.
Why do people sweat?
To cool the body. When it is hot, more water is lost by your body, so more water has to be taken in as drink or in food to balance this lost.
What two things does the body do when it is hot to regulate body temperature?
- Sweat.
2. Skin appears flushed.
Why does skin appear flushed when it’s hot?
Because there is an increased blood flow beneath its surface.
What 2 things happen if core body temperature is too high?
- Blood vessels supplying skin capillaries dilate (widen) to increase blood flow and heat loss.
- Sweat glands release more sweat, which cools the skin as it evaporates.
What 2 things happen if core body temperature is too low?
- Blood vessels supplying skin capillaries constrict (narrow) to reduce blood flow and heat loss.
- Muscles start to shiver, causing heat energy to be released by respiration in cells.
What is the main function of the kidneys?
To maintain the concentrations of dissolved substances in the blood.
What three things do the kidneys do?
- Regulate the amount of water in the blood.
- Regulate the amount of ions in the blood.
- Remove all urea in the form of urine.
How do water and ions enter the body?
When you eat and drink.
Why does the level of water and ions need to be maintained?
Because too much water moving into or out of the cells may damage them.