2i - excretion, coordination HUMAN NOT IN MOCK EXAM Flashcards
what is osmoregulation?
maintenance of water and salt content in the body. One of the jobs homeostasis has.
what is the internal environment?
the surroundings of the cells in the body. it particularly means blood, together with another liquid called tissue fluid
what is an example of homoestasis?
if you drink loads of water, homeostasis will respond by you urinating the same amount to automatically balance water input and water loss
what is tissue fluid?
watery solutions of salts, glucose, and other solutes. it surrounds all the cells in the body, forming a pathway for the transfer of nutrients between blood and cells. It is formed by leakage from the blood capillaries. It has a similar composition to blood plasma but lacks the plasma proteins
name some things which are regulated in the body
salt, water, CO2 levels in blood, blood pH, concentration of dissolved glucose, body temperature
what is the definition of homoestasis?
the ability of the body to maintain a constant internal environment
why is homoestasis important?
because cells will only function properly if they are bathed in a tissue fluid which provides them with their optimum conditions. e.g., if the tissue has too many solutes, the sells will lose water by osmosis and become dehydrated. if the tissue fluid is too dilute, the cells will swell with water. both conditions prevent the cells from working efficiently and can cause permanent damage. if the pH is not right, the enzyme activity will be affected, as well as body temp, it is also important that excretory products are removes as they cant build up in the blood and tissue fluid because they’d be toxic to all cells
what are the main solutes of urea. list them in order of amount in g/dm3
Urea (23.3), sodium chloride (salt) (10), phosphate (2.3), other nitrogenous waster (1.6), potassium (1.3), ammonia (0.4)
what is urea?
an excretory product of the kidney
what are some examples of nitrogenous waste? what does this mean? what is special about it? why?
ammonia and urea. they contain the element nitrogen. all animals have to excrete a nitrogenous waste product. This is because excess nitrogen (building blocks for proteins) can’t be stored in the body, whereas carbon, oxygen, and hydrogen can.
