Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
17 Cards in this Set
- Front
- Back
|
What is homeostasis?
|
The regulation of your body's internal environment.
|
|
|
What are hormones?
|
Chemical substances that coordinate many body processes.
|
|
|
What are the functions of the liver?
|
Deamination of excess amino acids to form urea.
Detoxifying poisonous substances and passing the breakdown products into the blood so they can be excreted in the urine via the kidneys. Breaking down old, worn out red blood cells and storing the iron until it is needed to synthesise more red blood cells. |
|
|
What are the functions of the kidneys?
|
They filter poisonous urea out of your blood. It is removed in your urine which is produced constantly by your kidneys and stored in your bladder.
|
|
|
How do your kidneys work?
|
Glucose, mineral ions, urea, and water are all diffused through the kidney tubules down a concentration gradient. The blood cells and larger molecules stay behind since they're too big to fit through the membrane of the tubule.
All glucose is reabsorbed by active transport. The amount of water and dissolved mineral ions reabsorbed varies (selective reabsorption). |
|
|
How does ADH control water balance?
|
If the blood becomes too concentrated, more ADH is released by the pituitary gland so the kidney reabsorbs more water. This results in a low volume of concentrated urine.
If the blood becomes to dilute, less ADH is released by the pituitary gland so the kidney reabsorbs less water. This results in a large volume of dilute urine. |
|
|
How does a dialysis machine work?
|
It restores the concentrations of dissolved substances to normal levels until they build up again. It must be repeated at regular intervals.
The dialysis fluid contains the same concentration of glucose and mineral ions so there's no net movement. It has no urea so there's a steep concentration gradient. |
|
|
What are disadvantages of dialysis?
|
You must follow a carefully controlled diet.
You must spend regular, long sessions connected to a dialysis machine. Most of the time the balance of your chemicals in your body is not normal so you feel tired and unwell. Over many years the balance of substances in the blood can become more difficult to control. |
|
|
What are the disadvantages of a kidney transplant?
|
You have to take immunosuppressant drugs every day of your life.
You need regular check ups to see if your body has started to reject the kidney. You may never get a chance of a transplant at all. |
|
|
What part of your brain controls the core body temperature?
|
The thermoregulatory centre. It contains sensors sensitive to temperature changes in the blood flowing through the brain.
|
|
|
How does your body regulate its temperature?
|
If it is too cold, the blood vessels supplying your skin capillaries constrict to reduce the flow of blood through the capillaries. This reduces the energy lost by radiation.
Less sweat is produced. Less water evaporates so less heat energy is lost. Your muscles contract and relax rapidly, causing you to shiver. This leads to lots of respiration which releases more energy, warming you up. Your hairs are pulled erect to trap in insulating layer of air. The opposite happens if you are too warm. |
|
|
When is insulin released?
|
When your blood glucose concentration rises after you have eaten a meal. It allows glucose to move from the blood into your cells where it is used. It also converts soluble glucose into insoluble gylcogen to keep your blood glucose levels stable. When the glycogen stores are full, excess glucose is stored as lipids.
|
|
|
When is glucagon released?
|
When your blood glucose concentration falls below the ideal range, glucagon is released from the pancreas. It makes your liver break down glucagon into glucose, releasing glucose into the blood.
|
|
|
What is type 1 diabetes?
|
Your pancreas doesn't make enough insulin or your blood glucose concentration isn't controlled. You eventually excrete glucose in your urine. Without insulin, your cells don't get glucose so you lack energy and feel tired.
|
|
|
What is type 2 diabetes?
|
Your body stops responding to insulin. It is linked to obesity, lack of exercise, or both.
|
|
|
How do you treat diabetes?
|
If you have type 1 diabetes, you need replacement insulin before meals. You also need to be careful about the levels of carbohydrate that you eat. You must have regular meals.
If you have type 2 diabetes, you must eat a balanced diet, lose weight, and do regular exercise. There are also drugs that help insulin work better, help your pancreas make more insulin, and reduce the amount of glucose you absorb from your gut. |
|
|
How do you cure diabetes?
|
Doctors can transplant a pancreas, however the operations are difficult and risky. There are not enough donors and it comes with the usual organ transplant problems.
Transplanting the pancreatic cells that make insulin. |
