Hormonal Coordination in Humans Flashcards
describe the endocrine system
is it composed of glands which secrete chemicals called hormones directly into the bloodstream
the blood carries the hormone to a target organ where it produces an affect.
compared to the nervous system, the effects are slower but act for longer
explain the role of the pituitary gland
is located in the brain and known as the ‘master gland’ which secretes several hormones into the blood in response to body conditions
these hormones in turn act on other glands to stimulate other hormones to be released to bring about effects
explain the role of the pancreas
produces and secretes the hormones insulin and glucagon which regulate the blood glucose concentration.
insulin reduces the concentration and glucagon increases the concentration of glucose in the blood
explain how insulin controls blood glucose levels in the body
if the blood glucose concentration is too high, the pancreas produces the hormone insulin that causes glucose to move from the blood into the cells.
in liver and muscle cells, excess glucose is converted into glycogen for storage
describe type 1 diabetes
disorder in which the pancreas fails to produce sufficient insulin and is characterised by uncontrolled high blood glucose levels and is normally treated with insulin injections
describe type 2 diabetes
where the body cells no longer respond to insulin produced by the pancreas - a carbohydrate controlled diet and an exercise regime are common treatments
obesity is a risk factor for type 2 diabetes
describe negative feedback
if the blood glucose concentration is too low, the pancreas produces the hormone glucagon that causes glycogen to be converted into glucose and released into the blood
describe what is meant by ovulation
where eggs begin to mature and one is released approximately every 28 days
explain some of the hormones involved in the menstrual cycle of a woman
FSH: causes the maturation of an egg in the ovary
LH: stimulates the release of an egg
Oestrogen and progesterone are involved in maintaining the uterus lining
describe the process of IVF
- involves giving a mother FSH and LH to stimulate the maturation of several eggs
- the eggs are collected from the mother and are fertilised by sperm from the father in a laboratory
- the fertilised eggs develop into embryos
- at the stage where they are tiny balls of cells, one or two embryos are inserted into the mothers uterus (womb)
state some costs of IVF
- very emotionally and physically stressful
- the success rates are not high
- it can lead to multiple births which are a risk to both babies and the mother
explain the role of thyroxine in the body
thyroxine from the thyroid gland stimulates the basal metabolic rate and plays an important role in growth and development
explain the role of adrenaline in the body
produced by the adrenal glands in times of fear or stress and increases the heart rate and boosts the delivery of oxygen ang glucose to the brain and muscles, preparing the body for ‘flight or fight’
