5.10 - Kidneys

• What are the functions of the kidneys?

  Regulate ion levels

  Regulate water levels

  Remove urea
• What is the process of Deamination?

  If the body has more amino acids than it needs, it can convert them into lipids or carbohydrates, which can be stored as an energy source for later.

  This is deamination and it takes place in the liver.

  The downside of this process is that it produces the waste product urea, which has to be excreted by the kidneys.
• What are the two ways ions are removed from the body?

  by the kidneys

  by sweating
• If we have too much water in the body, what could happen to our cells?

  They could gain water and burst
• Each kidney contains millions of tiny units called nephrons.
• Which hormone is responsible for regulating water levels in the body?

  Antidiuretic hormone (ADH)
• Which part of the brain detects the level of water in the body?

  Hypothalamus
• How the body responds to low water levels:

  1. Hypothalamus detects the low concentration of water in the bloodstream
  2. Hypothalamus sends signal to Pituitary Gland to release more ADH
  3. ADH travels around the body in the blood and stimulates kidneys to reabsorb more water from the tubules into the blood.
  4. less urine will be made ax concentration of water in the blood rises
• What is the first step in kidney function?

  Filtration
• How does blood pass through the nephron?

  Under high pressure
• What happens to small molecules during filtration?

  They pass into the nephron tubule
• Which small molecules are filtered into the nephron tubule?

  Urea, water, ions, and glucose
• Why do large molecules like blood proteins remain in the blood?

  They are too large to be filtered
• What is the purpose of selective reabsorption in the kidneys?

  To reabsorb needed molecules
• What molecules are fully reabsorbed by the kidneys?

  All glucose
• What is maintained in the blood plasma through selective reabsorption?

  Constant water level and mineral balance
• What happens to molecules that are not reabsorbed?

  They continue as urine
• Where does urine go after it is formed?

  It reaches the bladder