Topic 7 Flashcards
Control of metabolic rate
When there are low concs of thyroxine in blood, Hypothalamus releases TRH causing pituitary gland to release TSH causing thyroid gland to release thyroxine. The release of thyroxine directly brings about the decrease of thyroxine.
Adrenalin stimulates
Blood vessels widen for more blood flow to muscles
Heart pumps quicker and more strongly for higher heart rate and blood pressure
Liver cells change glycogen into glucose for extra glucose for respiration
Removing waste process hkidneys)
Renal arteries carry blood from the body to the kidneys
Kidneys remove substances from blood and make urine which is flows through ureters to urethra
Renal veins carry blood without waste back to body
Productions of urine
Blood flows through a network of capillaries called a glomerus in the Bowmans capsule of each nephron
Small molecules like water,urea and glucose are filtered out, whilst proteins and blood cells stay
In the first convoluted tube glucose & mineral ions are selectively reabsorbed by through active transport. No glucose is left in the urine.
Water is reabsorbed through osmosis in the loop of Henle and in the collecting duct
At the end of the nephron the remaining fluid flows into the ureter and the fluid contains excess water
What happens if the pituitary gland detects the water conc in blood is less
Release antidiuretic hormone (ADH) which cause the cells to become permeable, which means the volume of urine expelled is small but the concentrationsis high.
ADH controls
Permeability
Body controls high levels of glucose
Pancreatic beta cells in the Islets of Langerhams detect high glucose conc and then stimulates release of insulin from pancreas to convert glucose into polymer glycogen for storage
Body control of low levels of glucose
Pancreatic beta cells in the Islets of Langerhams detect low glucose levels in blood and release hormone glucagon, which converts glycogen into glucose
6 marker about menstruation and negative feedback loops
The menstrual cycle consists of menstruation, the thickening of uterine lining and ovulation. FSH stimulates the growth of follicles, which secrete oestrogen, which repairs the uterine lining. High levels of oestrogen stimulate the release of LH which triggers ovulation and the release of progesterone which maintains the uterine lining in anticipation fo fertilisation. Oestrogen inhibits FSH and progesterone inhibits both FSH & LH. Low levels of oestrogen and progesterone trigger menstruation. FSH causes the follicles to grow and release oestrogen and the cycle continues.
