5. Homeostasis and Response (diabetes and the kidneys) Flashcards
What is type 1 diabetes?
- An autoimmune disorder in which the pancreas does not produce sufficient insulin to control the blood glucose concentration
- As a result blood glucose levels are often very high
How can type 1 diabetes be treated?
- Insulin injections before meals - allows glucose to be converted into glycogen
- Limiting carbohydrate intake
- Pancreas and pancreatic cell transplants
- genetic engineering of pancreatic cells
What is type 2 diabetes?
A disorder in which the body’s cells stop responding to insulin, leading to an uncontrolled blood glucose concentration
What two things are possible triggers for type 2 diabetes?
increasing age and obesity
How can type 2 diabetes be treated?
- following a carefully-controlled diet
- doing regular exercise
- losing weight
- use of drugs which increase insulin production and effectiveness
What is osmosis?
The net movement of water particles from an area of high concentration to an area of low concentration, across a partially permeable membrane
What can very high levels of blood glucose concentration lead to?
excessive urination, tiredness and weight loss
In what ways is water lost from the body?
- during exhalation via the lungs
- sweating
- urine (some reabsorbed in the kidney)
What is deamination?
When excess amigo acids are converted into lipids or carbohydrates, which can be stored as an energy source for later. This process also produces urea, which has to be excreted by the kidneys
Where does deamination take place?
in the liver
What are the functions of the kidneys?
- remove urea
- regulate ion levels
- regulate water levels
In what ways are ions lost from the body?
- sweating
- urine (some reabsorbed in the kidney)
How are excess amino acids excreted from the body?
- excess amino acids are deaminated in the liver to form ammonia
- ammonia is toxic, therefore it is converted into urea
- urea is excreted from the body via sweat and urine
How do the kidneys maintain the balance of water and other substances in the body?
- filter blood in order to remove waste products eg. urea
- selectively reabsorb useful molecules eg. glucose, water, ions
What is the full name of the hormone ADH?
Anti-diuretic hormone
Where is ADH secreted in the body?
the pituitary gland of the brain
How does ADH affect the reabsorption of water in the kidneys?
- when the blood is too concentrated, the pituitary gland secretes more ADH
- ADH travels in the bloodstream to the kidney and increases the permeability of kidney tubules to water
- more water is reabsorbed in the kidneys, resulting in a smaller volume of more concentrated urine
Why is kidney failure dangerous?
When the kidneys are damaged, they may be unable to filter the blood properly. this may lead to:
- a build-up of toxic molecules (eg.urea) in the body
- an uncontrolled ion and water balance and cells being damaged as a result of osmosis
What are the two main ways of treating kidney failure?
- dialysis
- transplant
What is kidney dialysis?
The use of a specialist machine to carry out the function of the kidneys.
How does kidney dialysis work?
dialysis fluid contains the same concentration of glucose and ions as healthy blood. As a result, only excess and waste molecules are lost from the blood, and glucose and ions remain
What is genetic engineering?
changing a cell’s DNA so that it performs a desired function
If there is too much water in the body, what could happen to our cells?
- the water could enter our cells by osmosis
- causing them to swell up and possibly even burst
Which part of the brain detects the level of water in the body?
hypothalamus
What is selective reabsorption in the kidneys?
As the filtrate passes through the kidneys, useful substances like glucose are reabsorbed from the tubules into the blood
What is filtration or (ultrafiltration) in the kidneys?
as blood passes through the kidneys, small substances like glucose, amino acids, and water are absorbed from the blood into the kidneys
