Keeping Internal Conditions Constatnt Flashcards
What does homeostasis control
Temperature, blood glucose, water, ion content and levels of waste products
What are the waste products which have to be removed from the body
Carbon dioxide, from respiration, removed from the lungs when breathed out
Urea
Where is urea produced
The liver
What is urea produced from
The breakdown of amino acids
What is urea removed from and where is the done
It is removed by the kidneys from the urine
Where is urine temporarily stored
Bladder
When do water and ions enter the body
When we eat and drink
What happens it the water or ion content is wrong
Too much water may move in and out of the cells which could destroy the cells
What 3 important jobs do the kidneys do
Filter the blood
Excrete unwanted substances
Keep the vital substances
How does a healthy kidney produce urine
Filtering the blood
Reabsorbing sugar
Reabsorbing the dissolved ions needed by the body
Reabsorbing as much water as the body needs
Releasing urea, excess Ions and water ring the urine
Where is urine made
Kidneys
What can be used to keep someone with kidney failure alive
Dialysis
In a dialysis machine what does the blood flow between
Partially permeable membranes
What must the concentration of the dialysis fluid be in comparison to the patients blood
It must be the same concentration
Why must the concentration of the dialysis fluid be the same as the patients blood
So the useful substances, glucose and mineral ions do not diffuse out of the blood so they don’t need to b reabsorbed
Where does the urea go during dialysis
It diffuses out from the blood into the dialysis fluid
What is the purpose of dialysis
It restores the concentration of substances in the blood back to normal
What is inconvenient about dialysis
It need to be carried out at regular intervals
When may a person with kidney failure no longer need dialysis
If they have a kidney transplant
Why does dialysis fluid not just consist of water
All useful solutes would diffuse out of the blood as well as the urea
Where are kidneys for transplanting sourced from
Living donors or from a victim of a fatal accident
Why is it important that the kidney is well tissue matched
To prevent rejection
What happens in the process of Organ rejection
There proteins on the surface of cells know as antigens. The recipients antibodies may attack the antigen son the donor organ because they recognise them as being foreign
What drugs must be taken and why after an organ transplant
Immunosuppressants to suppress the immune response and prevent rejection
What is the risk of organ transplant
Due to the patient having to take drugs to suppress their immune system the patient is left vulnerable to common infections
What is the main advantage of a kidney transplant over dialysis
The patient does not have to be attached to a machine every few days
What temperature must the human body be kept at so the enzymes can work
37 degrees
What is the body temperatures monitored and controlled by
The thermoregulatory centre
Where is the thermoregulatory centre
The brain
What does the thermoregulatory centre have in order to control the body temperature
Receptors which detect the temperature of the blood flowing through the brain
What do the temperature receptors on the skin do
They send impulses to the brain to give information about skin temperature
Why does the skin look red when we are hot
Increased blood flow
What does sweating help to do
Coo, the body
Why must you drink lots on a hot day
More water is lost from the skin so more water must be taken in to balance this loss
If the core temperature rises what happens to blood vessels
The dilate allowing more blood to flow through skin capillaries and enemy is transferred through radiation and the skin cools
If the core temperature rises what happens in the sweat glands
Sweats glands produce more sweat. It’s water evaporates from the skins surface. The energy required for the water to evaporate comes from the skins surface. So we cool down and boys temperature falls
If the core temperature falls what happens to the blood vessels
The blood vessels near the surface of the skin constrict and less blood flows through rage skin capillaries. Less energy is radiated
Why do we shiver when our core temperature falls
Muscles contract quickly. This requires respiration and some of the energy released warms the blood
Why does sweating cool the body
The water in the sweat evaporates energy from the skin is used to turn the water into water vapour so the skin cools
What 5 things do doctors consider when deciding the course of action for a patient with kidney failure
The general health of the patient
How long the patient has been on dialysis
The total cost of treatment, long term cost of continuing dialysis over operation costs followed by immunise pressing treatment
The risks of transplanting, anethesthetics, infection
The availiability of donor kidneys
What are the ethical issues of kidney transplanting
Should everyone be automatically on a transplant register or should you opt in?
Should people be paid to be donors?
Should people pay for a new kidney to jump the queue?
Why is carrying a donor card or telling your family if you want to be a do not important
Donors are usually people who have died in accidents and it is distressing for families to make decisions about being a donor after they have lost a loved one
Why are extreme temperatures dangerous
The body’s enzymes will stop working
Children have a large ……
Surface area to volume ratio
Why do children in cold conditions get cold very quickly and dehydrate in hot conditions
Because of their large SA to volume ratio they transfer energy very quickly
What happens if the body temperature is too low
The respiratory enzymes work too slowly and too little energy is released
What happens if the child dehydrates
They cannot cool down and they overheat, which means enzymes denature
Why do old people get hyperthermia in cold conditions
They don not move around much to release energy from respiration in the muscles
What do explorers in extreme conditions learn in order to survive
Symptoms of hypothermia and dehydration
What does the pancreas control
It monitors and controls the level of glucose in the blood
If there is too much glucose in the blood what does the pancreas release
The hormone insulin
What does insulin cause to happen
The glucose to move from the blood into the cells
What happens to excess glucose
It is converted into glycogen for storage
Where is glucose converted into glycogen
The liver
What happens if no or little insulin is produced
The blood glucose becomes too high
What is the condition in which your blood sugar is too high known as
Type 1 diabetes
How is type 1 diabetes controlled
Injections of insulin and careful attention to diet and levels of exercise
What does insulin cause to happen
Blood glucose levels to fall
What happens if the blood glucose level gets too low
The receptors in the pancreas detect the low level
What does the pancreas release when blood glucose gets too low
The pancreas releases glucagon
What does the glucagon cause
The glycogen in the liver to change into glucose
What happens to the glucose produced from the glycogen
It is released back into the blood
How is insulin produced for injections to treat type 1 diabetes
It is produced by genetically engineered bacteria
When does a diabetic have to inject insulin
Before meals every day of their life
What must active diabetics do
Match the amount of insulin injected with their diet and exercise
What may other diabetics use instead of an injection
They use pumps attatched to the body and they can adjust the level of insulin injected by the pump
What are the 5 new possible new developments for treating and possibly curing type 1 diabetes
Pancreas transplants
Transplanting pancreas cells
Using embryonic stem cells to produce insulin secreting cells
Using adult stem cells from diabetic patients
Genetically engineering pancreas cells to make them work properly
What is homeostasis
Keeping the conditions of the body within a narrow ranges
