Kidneys and homeostasis Flashcards
Define homeostasis.
keeping the internal environment constant
What are the conditions inside the body that must be kept stable? (4)
1.water content of the body must be kept constant
2.waste chemicals must be removed from the body
3.body temperatures must remain constant
4.glucose levels must remain constant
What are the three functions of the kidneys?
- control water content of the blood
- removal of urea from the blood
- removal of excess mineral salts from the blood
What is the process of removing waste called?
excretion
What is urea?
a waste product made in the liver
What makes up urine?
urea, water and other waste
How is urine excreted?
Through the urethra
What does the structure of the kidney consist of?
-outer layer - cortex
-inner layer - medulla
How does blood enter the kidney? How does blood leave the kidney?
Enters through the renal artery
Leaves through the renal vein
What is the ureter?
A tube that carries urine from the kidney to the bladder
Where is urine stored?
The bladder
What is the urethra?
tube that carries urine from the bladder out of the body
What is the purpose of the nephron?
osmoregulation, removes excess salts and excess water from the blood
What are the two stages in the production of urine by the nephron?
- Ultrafiltration - filtration of small molecules under pressure from the capillary knot into the Bowman’s capsule
- Reabsorption - useful molecules are reapsorped back into the blood from the tube
What does the ADH hormone do?
Make the nephron more permeable to absorption of water