B3.3 - Homeostasis Flashcards
Where does the carbon dioxide in the body come from?
Respiration.
Where does the urea in the body come from?
The breakdown of amino acids in the liver.
How is carbon dioxide removed from the body?
Via the lungs when we breathe out.
How is urea removed from the body?
By the kidneys via the urine.
What will happen if the water and ion content of the body is wrong?
Too much water can move in/out of the cells, hence damaging them.
When do water and ions enter our body?
When we eat and drink.
How do kidneys produce urine? (5)
- Filtering the blood.
- Reabsorbing all the sugar.
- Reabsorbing the dissolved ions that the body needs.
- Reabsorbing as much water as the body needs.
- Releasing urea, excess ions and water as urine.
What is reabsorbed by the kidneys? (3)
- Dissolved ions.
- Water.
- Sugar.
What waste products must be removed from the body? (2)
- Carbon dioxide.
2. Urea.
What can be done if somebody has kidney failure? (2)
- Dialysis.
2. A kidney transplant.
What are the disadvantages of dialysis? (2)
- It may cause blood clots/infections.
2. It has to be done around 3 times a week for 3-4 hours.
What can be done to prevent donor kidneys from being rejected by the immune system? (2)
- Donors with similar tissues to the patient are used.
2. Patients take immunosuppressant drugs so that their immune system doesn’t attack the transplanted kidney.
What diffuses into the dialysis fluid?
Excess ions/water and waste products e.g. urea.
The dialysis fluid has the same concentration of dissolved ions as ____ ____.
Healthy blood.
In dialysis, the blood flows alongside a ____ ____ ____.
Partially permeable membrane.
What are antigens and where are they on cells?
Proteins on the surface of cells.
What can happen if the recipient of a kidney transplant’s immune system doesn’t recognise the antigens of the donor?
Their immune system will attack the antigens.
What happens to the enzymes in the body is the temperature is extremely high or low?
They stop working properly and therefore disrupt reactions.
What does sweating do?
Cool the body.
What conditions cause a greater water loss?
High temperatures.
What can be done to balance the water lost from sweat?
Eating and drinking.
What is homeostasis?
The maintenance of a constant internal environment.
Which part of the body monitors temperature?
The brain (the thermoregulatory gland).
How does the brain measure the temperature? (2)
- By monitoring the temperature of the blood flowing through the brain.
- Receptors in the skin send impulses to the brain.
What do blood vessels do when it is too hot and why?
They dilate so that more blood can flow through them and more heat can be lost.
What do sweat glands do when it is hot and why?
Release more sweat, which cools the body as it evaporates and takes away body heat with it.
What do hairs do when it is cold and why?
The hairs stand up in order to trap an insulating layer of air.
Why do muscles shiver when you are cold?
Their contraction releases some energy from respiration that warms the body.
What do blood vessels do when it is cold?
They constrict the flow of blood flow through capillaries.
Which organ monitors blood glucose?
The pancreas.
When is insulin produced?
When your blood sugar levels are too high.
When is glucagon produced?
When your blood sugar levels are too low.
What does insulin do?
Insulin makes the liver turn glucose into glycogen, and allows glucose to move from the blood and into the cells.
What does glucagon do?
Glucagon makes the over turn glycogen into glucose, and then releases the glucose into the blood.
What is Type 1 diabetes caused by?
The pancreas producing insufficient insulin levels.
How can Type 1 diabetes be controlled? (3)
- Avoiding food high in carbohydrates.
- Exercise.
- Injecting insulin.
