B11-Hormonal coordination Flashcards
What is the endocrine system?
a group of glands that secrete hormones directly into the bloodstream
How do hormones work
receptors on the target organ pick up the hormone molecule and trigger a response.
What are examples of hormones released by the pituitary gland?
FSH, LH, ADH
What is FSH?
causes maturation of egg and secretion of oestrogen
What is the order of glands from top to bottom and their function
- pituitary- master gland
- thyroid gland-controls metabolic rate
- adrenal- secretes adrenaline
- pancreas- controls glucose level in blood
- ovary/ testes- controls development of secondary sexual characteristics
What is a hormone?
chemical messengers with a target organ
Why do we need glucose?
to respire
How is the level of glucose detected in the pancreas?
receptors in the pancreas
What effect does insulin have?
reduces the amount of glucose
moves glucose from the blood into cells where it can be used for respiration or converted into insoluble starch
What happens when the glucose level is too low?
receptors in the pancreas detect the low glucose level and releases a hormone called glucagon. This causes the stored glycogen to be converted back to glucose.
Glucagon interacts with insulin in a negative feedback cycle to control glucose levels.
What is type 1 diabetes?
when the pancreas doesn’t produce enough insulin meaning the blood concentration of glucose isn’t monitored
without insulin glucose levels are very high and can eventually glucose is lost through urine
glucose doesn’t go to the cells and they don’t respire causing you to feel tired
genetic
What is type 2 diabetes?
linked with obesity and lack of exercise
pancreas makes less insulin than needed
body cells stop responding to the insulin
How is type 1 diabetes managed?
- insulin injections after every meal injected into the bloodstream. acts like normal insulin and allows glucose to go into cells
- pancreas transplant
- transplanting pancreatic cells
How is type 2 diabetes managed?
- exercise
- healthy diet
- loosing weight
What is a negative feedback system?
- work to maintain a steady state
- if changes occur to the environment, a change happens to try to bring the conditions back to normal
What is thyroxine and its negative feedback?
- produced by thyroid gland
- controls metabolic rate and how much oxygen is used by tissues
What is adrenaline?
- ‘fight or flight’ hormone
- makes heart rate increase and breathing to increase
- stored glycogen to convert to glucose for respiration
- mental awareness to increase
What are secondary sexual characteristics?
during puberty sexual hormones cause these:
- growth spirt
- more hair
- F breasts develop
- M testes grow and become active
Describe the hormones in the menstrual cycle
FSH is released by pituitary gland which causes egg to mature in the ovary and stimulates the release of oestrogen.
Oestrogen causes the uterus lining to thicken and inhibits the production of FSH
Pituitary gland releases LH which triggers ovulation
Once egg is released it triggers the release of progesterone which stops production of FSH and LH so no more eggs are released and also maintains uterus lining in case of fertilisation
if no fertilisation then progesterone levels fall.
FSH
causes egg to mature in ovary
LH
causes egg to release ovulation
