B12-Homeostasis in action Flashcards
What is the temperature human bodies need to stay at?
37 degrees C
Why is it important to keep body temperature constant?
for optimum enzyme function
What regulates core body temperature?
thermoregulatory centre in the hypothalamus
How do you cool down?
Vasodilation.
Blood vessels supplying blood to the capillaries dilate allowing more blood to flow through. You transfer more energy by radiating heat from your skin to the surface, this causes you to cool down and warms up the air around you
Sweat glands produce more sweat, extra sweat cools body down as the sweat evaporates and transfers energy to the surroundings.
You need to drink more water to balance this change
How does your body keep warm?
Vasoconstriction
What are the 2 main waste products?
Urea and Carbon dioxide
How is carbon dioxide formed and why is it important to get rid of it?
produced from respiration
broken down carbon dioxide produces an acidic solution which would affect enzyme action
How is CO2 removed?
diffuses from the cells into your blood down a concentration gradient and diffuses from the blood into the air in the lungs.
Removed when you exhale
What is urea?
Nitrogenous waste formed from the breakdown of excess amino acids in the liver
How does urea leave the body?
filtered out the blood by the kidney then passed out through the urine
What 4 things do kidneys filter?
- glucose
- mineral ions
- urea
- water
How much glucose is reabsorbed?
ALLLLLL
What is selective reabsorbtion?
the process by which kidneys selectively reabsorb the amount of water and mineral ions
What is the system that involved with ADH?
negative feedback
What happens when the water content in the blood is too high?
receptors in the brain detect the water content too high and stimulates the pituitary gland to release more ADH which causes the kidneys to reabsorb more water until the water content is back to normal?
What happens if the water content in the blood is too low?
receptors in the brain detect that there isn’t enough water content. Stimulates the pituitary gland to release less ADH which means less water is reabsorbed from the kidney.
What can cause a kidney to be damaged?
genetic or car accident
What is dialysis?
a persons blood flows through a partially permeable membrane and it filters the blood as if a kidney would
lose the bad stuff but equally as important that the useful things like glucose isn’t lost
8 hours to complete
How is the loss of glucose and needed mineral ions ensured in dialysis?
the dialysis fluid contains the same concentration of glucose and mineral ions as a healthy person and this ensures there’s no net movement of glucose.
excess mineral ions are removed through diffusion
Contains no urea which ensures as much urea as possible leaves the blood
What are the disadvantages of dialysis?
person has to have a very careful diet
have to always be near a hospital
What are the disadvantages of kidney transplant?
- eventually will fail and patient has to return to dialysis
- immunosuppressant drugs
- large risk of rejection
