Topic 5b The Endocrine system Flashcards
What are hormones
Hormones are chemical messages which travel in the blood to activate target cells
How are hormones carried around the body
Hormones are carried around the body in blood plasma and are used to regulate bodily processes
True or False Hormones affect all organs
False Hormones only affect particular organs known as target organs
Where are hormones produced
Hormones are produced and secreted in Glands known as endocrine glands.
Collectively these glands make up the Endocrine system
Name the glands which make up the Endocrine system and their particular role within the system
Pituitary Gland - produces many different hormones that regulate body conditions. Known as the MASTER GLAND because it produces hormones that act on other glands directing them what to do and what hormones to release
Pancreas - produces insulin used to regulate blood glucose levels
Thyroid - produces thyroxine which is involved in regulating rate of metabolism, heart rate and temperature
Adrenal Glands - produce adrenaline used to prepare the body for a fight or flight response
The Ovaries - produce oestrogen (involved in the menstrual cycle)
The testes - Produces testosterone which controls puberty and sperm production
Make a comparison between Nerves and Hormones
Nerves:
- Fast Action
- Act for a short time
- Acts on a very precise area
Hormones:
- Slower action
- Act for a long time
- Act in a more generalised way
What kind of response is adrenaline hormonal or nervous
Adrenaline is an hormonal response
How does the pancreas regulate blood glucose levels
- High levels of glucose in the blood are detected by the pancreas and cause it to release insulin
- Insulin travels around the body in the blood and binds to receptors on various cells causing them to take in glucose from the bloodstream and convert it to glycogen
- This bring the blood glucose levels back down
Explain what type 1 diabetes is
Type 1 diabetes is a condition where the pancreas produces little to no insulin resulting in a harmful rise in a persons blood glucose levels
Give three ways in which type 1 diabetes can be controlled
- Insulin Therapy - This involves regular injections of insulin throughout the day usually around mealtimes. Insulin injections ensure glucose is removed from the blood quickly and stop the blood glucose levels from getting to high.
- Dietary adjustments - These can include limiting the intake of foods rich in simple carbohydrates which cause glucose levels to rise rapidly.
- Regular exercise - This helps to reduce blood glucose levels due to the increased metabolism of cells which remove more glucose from the blood
What is type 2 diabetes and how can it be controlled
In type 2 diabetes the person’s body cells no longer respond to insulin produced by the pancreas. It is more common in older people. It can be controlled by a carbohydrate controlled diet and an exercise regime.
What is Filtration in regards to the kidneys
- Filtration is the process by which the kidneys make urine by extracting waste products out of the blood.
- Ions, Glucose and some water are absorbed back into the blood (SELECTIVE RE-ABSORPTION)
What is Urea
Urea is a waste product from the breakdown of proteins
Name three substances which should be present in the urine of a healthy person
Urea, Water, Ions
Give two ways in which water can be lost from the body
- Sweating = Water can be lost from the skin when the we sweat
- Breathing = Water is lost from the lungs when we breath out during the process of breathing
- Urinating = Water in the body is balanced by the amount we consume and the amount removed by the kidneys in the urine
True or false the hotter your body gets the less water you need to take in
False
The water lost when it is hot has to be replaced with water taken from food and drink to restore the balance in the body
Which process can cause cell damage if the ion or water content of the cell is unbalanced
Osmosis
What is deamination
Deamination is the process by which excess amino acids are broken down by the liver and converted into fats and carbohydrates to be stored.
The waste product from this breakdown is called ammonia which is toxic so it is further broken down into urea.
Urea is the transported to the kidneys where it is filtered out of the blood and released from the body as urine
What is the role of the kidneys in the body
- Filtration of waste products from the blood
- Tubular re-absorption of useful substances (glucose, ions, water)
- Tubular secretion of unwanted substances (urea, excess ions and water)
- Maintaining blood pressure by balancing electrolytes water and ion levels in the blood
How can people with kidney failure be treated
Dialysis:
- machines are used to mimic the role of the kidneys and filter the blood.
- Needs to be done regular in order to maintain a healthy balance of dissolved substances in the blood (glucose, ions etc) and remove waste products
Kidney Transplant:
- The diseased organ is replaced by a healthy one
The level of dissolved sodium (ions) found in dialysis fluid before a dialysis session is similar to the typical level found in the blood plasma. Why is this?
To ensure none of the useful sodium ions are lost from the blood during the dialysis treatment. Only waste products such as urea and excess ions will diffuse across the partially permeable membrane out of the blood (area of high concentration to an are of low concentration)
Blood plasma contains urea, dialysis fluid does not. Why is this?
Because urea is a waste product which is carried to the kidneys in the blood and is not needed
Blood plasma contains glucose.
How would the amount of glucose found in a dialysis machine compare to the amount of glucose found in the blood plasma
there will be a similar amount. Glucose isnt a waste product its a substance that the body needs. If there are similar amounts in both the blood and the dialysis fluid then the glucose wont be lost through diffusion during dialysis session.
True or false people with kidney failure only need dialysis once
false - dialysis needs to be done regular in order to keep to levels of ions and glucose at normal as well as remove waste product
Give an example of a substance that can’t pass through the partially permeable membrane used to filter the blood in a dialysis machine
Protein - The protein molecules are to large to pass through the membrane
list the problems associated with having a kidney transplant
- There are long waiting lists for kidneys
- Even if a kidney with a matching tissue type is found, there is still a risk of rejection from the recipients body (Antigens molecule found on kidney cell not recognised by recipient white blood cell, antibodies produced, kidney cells are attacked)
- Kidney transplant is a major operation so there are serious risks attached.
- The patient has to take drugs that suppress the immune system (they reduce the production and release of antibodies by the white blood cells so the cells wont attack the new kidney) so become more susceptible to other infections
How can the rejection of an organ during a kidney transplant be prevented
- A donor with a tissue type that closely resembles the patient can be used. Similar tissue types have similar antigens and therefore the likely hood that the recipients body deems the new organ to be foreign is reduced so the body doesn’t produce antibodies to attack it
- The patient can take drugs that suppress the immune system (they reduce the production and release of antibodies by the white blood cells so the cells wont attack the new kidney)
List the problems associated with dialysis
- Not an enjoyable process taking 3-4 hours 3 times a week
- Can lead to infections and cause blood clots
- Diet has to be carefully structured too avoid the build up of particular ions between dialysis sessions
- Costs a lot for the NHS to run
List the problems associated with dialysis
- Not an enjoyable process taking 3-4 hours 3 times a week
- Can lead to infections and cause blood clots
- Diet has to be carefully structured too avoid the build up of particular ions between dialysis sessions
- Costs a lot for the NHS to run
Delamination simplified
Delamination is amino acids broken by liver into fats/carbs. Waste produced = Ammonia broken into Urea
Amonia moved to kidney filtered out blood released as urine
What is the thyroid
Gland - thyroxine - control rate of metabolism - temperature - heart rate
