homeostasis Flashcards
define hormones
hormones are chemical messengers that travel through the blood stream to reach target organ
define the term negative feedback
what happens when there is low thyroxine levels
stimulate the hypothalamus to release TRH and this causes the pituitary to release TSH so the thyroid releases more thyroxine. So blood levels return to normal.
purpose of adrelin
it is release from the adrenal glands and breaks down glycogen.
Explain the menstrual cycle
day 1-5 menstruation the uterus lining breaks down.
day 11-13 - the uterus lining starts to thicken.
Day 14 - ovulation starts
day 215-28-the lining increases
the hormones involved in menstrual cycle
FSH causes the follicles to mature, the maturing follicles release oestrogen . The oestrogen causes the uterus lining to thicken and LH is released. LH causes ovulation . Follicles turns into corpus lutuem and releses progesterone.
what is clomifene therapy
clomifene is a drug used to help increase the concentration of FSH and LH in the blood
What is IVF
(in vitro fertilisation) egg follicle maturation stimulated by hormones . then the egg cell is released by many follicles and taken from the ovary. The sperm is taken by the man. the egg and sperm are fused and placed back into the body
what happens to glucose during respiration
glucose is released from carbohydrates in our food.The glucose is absorbed by the blood and into cells then it is broken down during respiration
what will happen when the blood glucose concentration decreases?
As blood glucose concentration falls, the insulin-releasing cells in the pancreas release less and less insulin .
compare the roles of glucagon and insulin in the control of blood glucose concentration
when the glucose is absorbed by the liver, it is converted to glycogen, which is stored in the liver cells. glucagon causes the liver cells to convert glycogen back to glucose, which is released into the blood.
what is the difference between type 1 and 2 diabetes
in type 1 diabetes , the pancreatic cells are rejected by the immune system meanwhile in type 2 diabetes the muscle or liver cells are insulin resistance or not enough insulin is being produced
in type one diabetes people are injected by insulin meanwhile type 2 diabetes they are advised to change diet /exercise.
what is the meaning of hypothalamus and thermoregulation
hypothalamus is a small of the brain that monitors body temperatures
thermoregulation is the control of body temperatures
what happens when the body temperatures is lower than 37C
the body will shiver and the muscles will contract and relax rapidly. The erector muscles will contract and the body hair will stand upright (the hairs will trap air insulating the body) the blood cells will narrow vasoconstriction
what happens when body temperatures increases
the body will start sweating . the sweat will evaporate causing a cooling effect. the blood flow will increase towards the surface.the arteries would widen (vasodilation)
what is osmoregulation
it is the control of the balance of water and mineral ions
what happens when you have a high diet in protein
the excess proteins are digested into amino acids that is absorbed ibnto the blood. the excess amino acid are then deaminated in the liver to form ammonia . ammonia is converted into urea for safe excretion from the body in the urine
what is the function of the kidney
1 filtration of glucose ,urea,ions and water from the blood
selective re-absorption of all glucose ,some salts and some water into the blood
3 excretion of all urea ,excess ions and excess water into the urine
what are the treatment for kidney failure?
kidney dialysis
kidney transplant
Blood is filtered in the kidneys. Blood enters the renal capillaries at a high pressure. The high pressure means that the blood can be filtered by the glomerulus of the nephrons, which has small holes to allow molecules through. Some substances are reabsorbed. At each stage of the nephron certain substances are reabsorbed. Glucose, water and some ions are reabsorbed, whilst urea doesn’t tend to be reabsorbed (its not useful so we want all of it to go into the urine!).
