endocrine system -hormonal control Flashcards
what is the endocrine system
a number of glands that secrete hormones that are released directly into the blood stream. each hormone acting on specific target Organs where it produces an affect
differences between nervous system and endocrine system
n - uses electrical impulses which travel down neurones
e- uses hormones which are chemicals carried into the blood stream
n - signalling in system is extremely fast
E - produces a much slower effect which is more long lasting
what does the pancreas gland do
releases hormones involved in controlling the concentration of glucose in the blood
function of ovary and testes glands
release hormones involved in puberty and in reproduction
function of thyroid gland
produces hormones involved in growth and in regulating the body’s basal metabolic rate
adrenal glands
releases
adrenaline - produced in times of fear or stress
function of pituitary Gland and significance
releases a number of different hormones depending on the body’s conditions
pG hormones act on other glands and cause other hormones to be released
what are glucose concentrations in the blood important to be kept maintained and constant
glucose is needed in every cell to release energy by respiration
so is is crucial glucose conc in blood is kept constant
(part of homeostasis) - which is monitored by pancreas
what happens in type 1 diabetes
pancreas does not produce enough insulin to bring blood glucose levels back to normal quickly so must have insulin injections after e.g carb rich meal
what happens in type 2 diabetes
body cell stop responding to insulin produced by pancreas. so blood glucose levels rise to high
treated with a diet of controlled level of carbohydrates - preventing blood glucose levels rising to high - and excercise
risk factor - obesity
what happens to a person if the blood glucose concentrations fall
if conc is too low the pancreas releases the hormone glucagon into the bloodstream
what does glucagon
triggers liver cells to convert glycogen stores back to glucose, which is released into the blood. causing blood glucose concentration to return to normal
what
is negative feedback
the opposite effects of insulin and glucagon on the blood glucose conc
function of adrenaline
increases heart rate - heart beating faster leads to more oxygen and glucose delivered into the blood, Brian and muscles.
which are both needed for aerobic respiration - preparing Body for fight or flight
2 main affects of thyroxine
- stimulates body’s basal metabolic rate (makes chemical reactions take place at a faster rate)
( metabolism is sum of all chemical reaction s in a cell/body)
- plays an important role in growth and development
level in blood is controlled by negative feedback
function of adrenal glands - ( located above kidneys)
during times of fear or stress they produce adrenaline, which is released into the blood and increases the heart rate - this leads to more oxygen and glucose ( needed for aerobic respiration) delivered in blood to brain and muscles
how does negative feedback work with hormone thyroxine as an example
if level of thryoxine falls events are triggered which causes levels of thyroxine to increase
if levels are to high events are triggered to bring the levels back down > negative feed back cycle
