B11.1 - B11.5 - Hormonal Coordination (set A)✔️ Flashcards
What is the endocrine system and what does it compose of?
System is composed of glands that secrete chemicals called hormones directly into the blood stream - hormones carried by the blood to a target organ where it produces an effect
Two examples of rapid response hormones?
- insulin - controls your blood glucose
- adrenaline - prepares body for fight or flight
Two exmaples of slow-acting hormones?
- growth hormones
- sex hormones
What is the thermoregulatory center in the brain?
thermoregulatory centre monitors and controls the bodies temperature it is able to do this because it contains receptors sensitive to the temperature of the blood - skin also contains temperature receptors aswell and sends nervous impulses to the thermoregulatory centre
What does the body do when temperatures are too high?
Blood vessels dilate (vasodilation) and sweat is produced from the sweat galnds - both these mechanisms cause a transfer of energy from the skin to the enviorment
What does the body do when temperatures are too low?
Blood vessel constrict (vasoconstriction), sweating stops and skeletal muscles contract (shiver)
Why do the skeletal muscles contract (shiver) when we are cold?
The energy that’s transfered to make your muscles produce shivers, gives off heat, helping to keep you a bit warmer
Why do our bodies sweat to cool down?
takes energy to evaporate sweat off of your skin, and that energy is heat. As your excess body heat is used to convert beads of sweat into vapor, you start to cool down
What is the pituirary gland? What is its function?
Called the ‘master gland’ which secretes several hormones into the blood in response to body conditions - these hormones act on other glands to stimulate other hormones to be released to bring about effects
Which organ monitors and controls blood glucose concentration?
Pancrease - manages and controls blood glucose concentrations
What happens if the blood glucose concentration is to high?
The pancrease produces the hormone insulin that causes glucose to move from the blood into the cells - in the liver and muscles cells excess glucose is converted to glycogen
Why do muscles cells and the liver convert excess glycose to glycogen?
Converts excess glucose to glycogen for storage until later use
Role of the endocrine gland ‘thyroid’?
Controls metabolic rate of the body - metabolism in the process where the body changes food and drink into energy
Role of the endocrine gland ‘pancrease’?
Controls glucose levels in the blood
Role of the endocrine gland ‘adrenal’?
Prepares the body for stressful situations - ‘fight of flight’ response
Role of the endocrine gland ‘Ovaries’?
Controls development of the female secondary sexual characteristics and is involved in the menstural cycle
Role of the endocrine gland ‘testes’?
Controls development of the male secondary sexual characteristics and is involved in the production of sperm
How does the pancrease control glucose levels in the blood?
- Produces insulin when your blood glucose concentration rises (eg after you eaten a meal) - insulin alows glucose to move from the blood into your cells where it is used - soluble glucose is converted into insoluble glycogen - this results in your blood glucose staying stable
- releases glycagon when blood glucose concentrations decrease - converts stored glycogen to glucose and releases it into the blood
Two main functions of insulin?
- converts soluble glucose into insoluble glycogen and controls its storage in the liver and muscles where it can later be converted back
- allows glucose to move from the blood into your cells where it is used
What is Type 1 diabetes? Symptoms? Treatment?
A disorder in which the pancrease fails to produce sufficient insulin - characterised by uncontrolled high blood glucose levels and is normally treated with insulin injections
What is Type 2 diabetes? What are some treatments?
The body cells no longer respond to insulin produced by the pancrease - carbohydrates controlled diet and frequent exercise are common treatments
Example of 1 risk factor for Type 2 diabetes?
- obesity
How is Type 1 diabetes treated?
You need replacement insulin before meals usually given as an injection to get into your blood which keeps blood glucose levels stable - you need to be careful about the levels of carbohydrates you eat and careful when exercising
How is type 1 diabetes cured?
There is currently no cure - someone with Type 1 diabetes will have to inject insulin everyday for their life however there have been attempts at a cure with limited success eg pancrease transplant
Issues with trying to cure Type 1 diabetes?
- pancrease transplants are difficult and risky with only a few hundred taking place a year in the uk
- patient exchanges one medecine (insulin) for another
- transplanting the pancreatic cells from both living and dead donors has had limited success
Example of 4 ways to help treat Type 2 diabetes?
- eating a balanced diet with carefully controlled amounts of carbohydrates
- losing weight
- doing regular exercise
- drugs - to help pancrease make more insulin
What does the pancrease do when blood glucose concentration are too low?
Produces the hormone glycagon that cause glycogen to be converted into glucose and released into the blood
What is a negative feedback system?
Whatever the inital change, in negative feedback the response causes the opposite
What is the function of thyroxine? Where is it released? What feedback loop is it?
Prouced by the thyroid gland in your neck using idodine from your diet - it controls the basic metabolic rate of your body (how quickly substances are broken down and built up) and is important for growth and development - controlled by negative feedback
What are the features of adrenaline? is it fast acting?
Released by your adrenal gland located at the top of your kidneys - it is carried rapidly around the body in the blood affecting many organs - not controlled by negative feedback
4 examples of the effect of adrenaline?
- heart rate and breathing increase
- pupils in eyes dilate to let more light in
- blood diverted from digestive system to big muscles
- stored glycogen is converted to glyucose
Effect of glycaogn?
Secreted by the pancrease when blood glucose concentrations are too low it makes your liver break down glycogen converting it back into glucose
How are the bodies blood glucose levels kept constant?
Using a negative feedback control consisting of two hormones (insulin and glucagon)
Give two uncontrollable ways water leaves the body?
- via the lungs during exhalation
- lost alongside ions and urea frm the skin in sweat
How is ammonia formed in the body and why?
The digestion of proteins from the diet results in excess amino acids which need to be excreted safely - in the liver these amino acids are ‘deaminated’ to form ammonia which is toxic and immediately converted to urea for safe excretion
Explain the function of the kidneys?
Produces urine by filtering the blood - it then reabsorbs all of the glucose, plus any minreal ions and water needed by your body - excess minreal ions, water and urea are removed in urine
What is the bodies water ballance controlled by?
The negative feedback system containing the hormone ADH - changes the amount of water reabsorbed by the kidney tubules - ADH is secreted by the pituitary gland in the brain
Explain in depth the process the bodies water balance is maintained?
- receptor cells in the brain detect the concentration of solutes in the blood plasma
- if blood becomes to concentrated lots of ADH is released into blood which causes the kidneys tubules to reabsorb much more water
Effect of lots of ADH being released into the blood?
More water reabsorbed by kidney tubules - small volume of very concentrated urine and concentration of solutes in blood returns to normal
Effect of less of ADH being released into the blood?
If solute concentration becomes to dilutes less ADH is released into blood - less water is reabsorbed produces a large volume of dilute urine - blood solute concentration returns to normal
How can people with kidney failure be treated?
- organs transplant
- kidney dialysis
