MB S3 Flashcards
Animals can only survive if the liquids in cells and in-between have an adequate supply of oxygen and water and if wastes such as carbon dioxide and nitrogenous wastes are removed, what is essential in doing this?
the excretory and the respiratory systems
In summary the respiratory system is for?
the respiratory system is the organ system concerned with the intake of oxygen when necessary for cellular respiration and the removal of carbon dioxide which is toxic in high concentrations.
Plants produce what in photosynthesis? and what in respiration?
produce oxygen in photo synthesis, and carbon dioxide in respiration
water is a ?
excellent solvent
water dissolves other substances so it can?
react chemically
what is the main function of water in the body?
to act as a medium for chemical reactions
The concentration of water in cells must be held constant, this is because water is a major solvent for chemical reactions and the amount of water will affect?
the concentration of materials in the cell
water also has a very high?
specific heat capacity
The very high specific heat of water means that?
it absorbs large amounts of heat for a relatively small change in temperature.
temperature tends to remain relatively constant in cells that contain?
adequate amounts of water.
Metabolic wastes must be removed because?
some are poisonous, some take up space, some would create problems with osmoregulation.
the excretory system is concerned with the removal of metabolic waste products from the body, in humans state the organ systems for excretion.
the kidneys, the lungs (CO2 removal) and the skin
what else is the excretory system responsible for?
for the maintenance of constant blood composition, therefore maintaining a constant internal environment in cells.
the kidney has a dual role of?
excreting nitrogenous wastes and maintaining the water balance in mammals and fish
the kidney is an organ of?
filtration, re absorption and secretion
when amino acids are broken down what is produced?
ammonia is produced
Ammonia is?
extremely toxic, very soluble and diffuses readily across cells.
In some fish ammonia?
may diffuse out the gills and be excreted through the kidneys in a dilute urine
in mammals, sharks and some bony fish ammonia is?
in the liver converted to a urea, which is less toxic. this is so that it can be stored briefly, though it is less soluble.
Blood carrying nitrogenous wastes is brought to the kidneys by the?
renal arteries
urine is formed?
in the kidneys outer cortex and the central medulla, the pelvis connects the medulla to the ureter which takes the urine to the bladder for short term storage.
depending on the environment of the fish or mammal, the kidneys excrete urine with?
a range in concentration
when forming a concentrated urine what can be told about the organism?
the kidneys are helping the fish/mammal live in a dehydrating environment. so as to reabsorb water into the blood and maintain water balance
when forming a dilute urine what can be told about the organism?
fresh water fish excrete a dilute urine to help over come a water balance problem resulting from an influx of water that diffuses in from their environment.