Water balance Flashcards
What is homeostasis?
Maintaining a constant internal environment involving the nervous and hormonal communication systems.
For cells to function properly and to remain at steady levels what is there throughout the body?
Control systems are throughout the body maintaining everything at steady levels. They consist of receptors detecting changes in the environment, processing centres to receive info and coordinate responses, effectors to produce the response.
What is negative feedback?
Negative feedback is the body returning itself to normal, restoring temperature if it rises or falls by reversing any changes.
Why is a balanced water level important?
Cells can shrivel up or explode if there is too little/much water. Our body must balance the gain of water from drinking and the loss through sweating and urinating.
How do we maintain a healthy water balance in cells?
Blood plasma in cells controls how much water there is, if the concentration of plasma is too high, the cells will lose too much water, if the concentration is too low, the cells will absorb water and burst.
How do kidneys help the body maintain a healthy water balance?
The kidneys respond to changes in blood plasma by changing the concentration of urine excreted. ADH is released by the pituitary gland to control this, releasing ADH causes urine to be more concentrated (less water)
How do drugs affect the Kidneys?
Alcohol suppresses the release of ADH, so less water is reabsorbed by the kidneys, more water lost in urine. Ecstasy increases ADH release, so more water is reabsorbed and by the kidneys, less water lost in urine.
