B7: Homeostasis Flashcards
Homeostasis
The process by which automatic control systems maintain almost constant conditions within the body.
Hormones
Chemical substances that coordinate many body processes.
What does sweating affect?
The temperature and water content of the body.
How does sweating cool the body?
It uses heat energy from the skin to evaporate the water.
% of CO2 coming into the body vs going out
In: 0.04% Out: 4%
3 functions of the liver
> Deamination of excess amino acids > Detoxification of poisonous substances > Breakdown and production of Red Blood Cells (Stores Iron)
What is in Urine?
Urea Excess mineral ions Excess water
Urobilin
A yellow pigment excreted in urine from the breakdown of haemoglobin in the liver.
How is glucose reabsorbed from the kidneys?
Active Transport (against a concentration gradient)
Deamination
The removal of an amino group from an amino acid.
Selective Reabsorption
The varying amount of water and mineral ions that are taken back into the blood in the kidney, depending on what is required by the body.
Where are hormones produced?
The endocrine glands
What does adding ADH do?
Makes the kidney more porous.
Negative Feedback System
A system of control based on an increase in one substance triggering the release of another which brings about a redirection in levels of the initial stimulus.
If less ADH is released, is more or less urine produced?
More, but less concentrated.
What does dialysis rely on?
Diffusion down a concentration gradient.
What is in dialysis fluid?
Water Glucose Mineral Ions
What is removed from the blood during dialysis?
Urea Excess Salt
Disadvantages of a kidney transplant
> They don’t last forever > Immunosuppressant drugs
Disadvantages of dialysis
> Carefully controlled diet and exercise > Takes 8 hrs several times a week
Where is the thermoregulatory centre?
Hypothalamus
Body’s cooling mechanisms
> Blood vessels vasodilate (more heat lost through radiation) > Sweat (evaporation takes heat energy from blood) > Hairs lie flat (less insulation)
Body’s heating mechanisms
> Blood vessels vasoconstrict (less heat lost through radiation) > Hairs stand on end (trap an extra insulating layer of air) > Shivering (muscles contract and relax rapidly, which releases more energy)
Glucose Glycogen Glucagon
Sugar Storage Carbohydrate Hormone
2 hormones produced in the pancreas
Insulin Glucagon
What does glucagon target?
Glycogen, to turn it back into sugar from the storage carb that insulin made it into. (stored in the liver)
Insulin
A hormone that reduces blood glucose concentration.
Glucagon
A hormone that increases blood glucose concentration.
Diabetes
When your blood glucose cannot be controlled because the pancreas isn’t making enough, or any, insulin, or the body has stopped responding to it.
Type 1 Diabetes
> When the pancreas stops/decreases insulin production. > Treated by insulin injections
Type 2 Diabetes
> Insulin is still produced but the body cells stop responding to it. > Treated by controlled diet and exercise.
