Homeostasis and Response - Bio

• Homeostasis is maintaining a stable internal enviroment
• Homeostasis is super important because your cells need the right conditions in order to function correctly, including enzyme action
• all of your automatic control systems are made up of 3 main components; RECEPTORS , EFFECTORS and COORDINATION CENTRES
• Negative feedback is what counteracts change
• kidneys act as a filter to ‘clean the blood’ of waste products (such as urine) and excess water
• filtration is a process in which waste products (e.g. urea, iond and water) are removed from the blood
• Selective Filtration is the process of useful products (e.g. glucose, some ions and the right amount of water) are reobsorbed back into the blood.
• ADH (anti-diabetic hormone) is released into the blood stream by the pituitary gland.
• tthe brain monitors water content of blood and instructs the pituitary gland to release ADH according to what is needed (controlled by negative feedback)
• there are two treatments to kidney failure: DIALYSIS and KIDNEY TRANSPLANT.
• removal of blood from body through a cleansing machine is called Dialysis
• kidney is transplanted through surgery is a kidney transplant
• DIALYSIS CON: expensive , time consuming , inconvenient , need to be monitored
• DIALYSIS PRO; effective
• KIDNEY TRANSPLANT PRO; cheaper, patient can live normally, quick and one treatment
• KIDNEY TRANSPLANT CON; major surgery, can be rejected, waiting list
• kidney failure; if your kidneys do not work, waste substances build up in your blood and you loose the ability to control the level of ions and water in your body, eventually being fatal.
• the menstrual cycle is the monthly release of an egg.
• the menstrual cycle lasts 28 days, and give or take on the person they have the same amount of days for each stage
• Stage one of the menstrual cycle (day 1-4) consists of the uterus lining breaking down
• stage 2 of the menstrual cycle (day 4-14) the uterus lining builds up
• stage 3 of the menstrual cycle (day 14) is ovulation, where the egg is released.
• ovulation happens on the 14th day of the menstrual cycle and consists of the egg being released
• stage 4 of the menstrual cycle (day 15-28) is where the uterus lining is maintained. then, the cycle repeats back to day 1.
• FSH (follicle-stimulating hormone), LH (luteinising hormone), Oestrogen and Progresterone. these four hormones control the menstrual cycle.