Homeostasis

• Dialysis is a procedure to remove waste products and excess fluid from the blood when the kidneys stop working properly
• is the body stops operating in optimal internal conditions, enzymes denature and there are slower metabolic reactions
• the body must regulate glucose levels, water levels, body temperature, urine and carbon dioxide levels
• The part of the brain that regulates body temperature is the hypothalamus.
• the brain is sensitive to the temperature of blood
• if body temperature increases, sweat increases
• the liver stores glucose
• insulin decreases blood glucose level
• the kidney produces urine
• water is drank to replace water loss after exercise that is lost in sweat
• kidney transplants may be rejected from the body and there may be a shortage of donors
• the liver produces urea
• the lungs remove carbon dioxide
• if the kidneys produce little urine, the body cells swell and become damaged
• if the kidneys produce too much urine, the blood becomes concentrated with salts which can cause dehydration
• effectors carry out responses to stimuli
• the function of the receptors in skin is to detect any changes in the surroundings to convert information to send impulses
• the muscle is an effector that carries a response for contraction
• glands are effectors that carry responses to release chemicals, produce hormones
• it is important to maintain temperature of the body, because we need to maintain the temperature at which enzymes can work their best
• there are receptors in the skin
• a reflex action is different from an action controlled by hormones because hormones involves blood system and reflex involves neurones
• reflex actions involves impulses and hormone involves chemicals
• damage to cells in the pancreas means less insulin can be produced, therefore there is a higher chance of increase in blood glucose concentration
• insulin cannot be taken as a tablet, because it would end up being digested. Insulin needs to travel directly into the bloodstream
• a hormone is a chemical messenger
• the thyroid gland regulates metabolism and growth and is located in the neck
• hormones are transported to their target organs by the bloodstream
• when core body temperatures begin to fall, muscles shiver, and blood vessels that supply the skin capillaries begin to constrict
• when body temperatures are too low the blood vessels suppling the skin capillaries constrict to have less blood flow to loose less heat
• there are temperature receptors in the thermoregulatory centre
• the thermoregulatory centre detects blood temperature
• the temperature receptors in the skin sends impulses to the thermoregulatory centre giving information on skin temperature
• if body temperature is too high blood vessels supplying the skin capillaries dilate, they undergo vasodilation so that more blood flows near the surface of the skin so more heat can be lost
• sweat glands release sweat to cool the body
• sweat cannot evaporate if there is a higher humidity in the air, this means less of a cooling effect
• urine contains mineral ions and urea but no glucose or protein