Brief overview of the homeostasis section of B2. I made it to REMIND me of key ideas. It is not intended to be a full set of revision notes.
1) During metabolic reactions waste products are produced. These must be removed from the body.
a) Carbon dioxide (from respiration)
i) Carbon dioxide from the blood diffuses into the alveoli in the lungs, and is exhaled.
b) Urea (from the breakdown of excess amino acids in the liver, or deamination)
i) Urea is filtered forcefully through capillary walls in the glomerulus (inside a kidney nephron) by an increase of pressure. Other useful products in the filtrate such as glucose and mineral ions are selectively reabsorbed. The urea and other excess substances collect in the bladder (as urine) before being excreted.(see unit 3)
2) Homeostasis is the control of internal body conditions like…