Excretion Flashcards
Excretion
the removal of waste products of metabolism from the body
egestion
the removal of undigested material from the gut
is egestion an example of excretion?
no
why do plants not have as great a need for excretion as animals?
because they make there own food (photosynthesis)
what do plants lose during the day?
oxygen and water vapour
through what are CO2, oxygen and water vapour excreted in the plant
the stomata and the lentils of the stem
what do plants lose at night?
CO2
what are lenticles
small pores in the stems
some carbon dioxide produced in photosynthesis
used in respiration by the plant
some carbon dioxide used in respiration
used in photosynthesis by the plant
where are waste products stored in the plant
in the vacuoles in the leaves
how do the plants get rid of the waste products
when the leaves fall off
meaning of homeostasis
staying the same
definition of homeostasis
the maintenance of a constant internal environment in an organism
2 roles of excretion in homeostasis
removing of waste products of metabolism from the body
control of water and salt balance in the body
osmoregulation
the maintenance of water and salt balance in body fluids
4 excretory organs in the human
kidneys
skin
lungs
liver
what do the kidneys excrete
water salts and urea
what does the skin excrete
water and salts in the form of sweat
what does the lung excrete
carbon dioxide and water
what does the liver excrete
bile pigments
what are bile pigments a product of
the breakdown of haemoglobin
urea
formed when excess amino acids are broken down in the liver
where are the kidneys located
in the abdominal cavity in the small of the back
2 functions of the kidney
excretion
osmoregulation
urine formed in
the kidneys
urine passes to bladder via
the ureters
urine released via
urethra
blood enters kidneys through
the real arteries
blood in renal arteries
high in waste products
what do the kidneys do to the blood
filter out waste and reabsorb useful materials
blood leaves kinky via
renal veins
blood in renal veins
purified blood
3 sections of kidney
cortex
medulla
pelvis
cortex
outer part of kidney
4 things in the cortex
glomeruli, Bowman’s capsule, distal and convoluted tubules
2 things in the medulla
loops of Henle and collecting ducts
Pelvis
the space int which the urine is collected from the collecting ducts
ureters
the tubes that carries the urine from the kidneys to the bladder
how many ureters do we have
2
nephron
functional unit of the kidney
nephrons are also called
kidney tubules
kidneys are made up of
millions of nephrons and their blood supply
nephrons carry out 2
excretion
osmoregulation
what does the great number of nephrons provide?
a large surface area for exchange of materials with the blood
blood flow in the kidneys
renal artery -> many afferent arterioles -> glomerulus -> efferent arteriole -> capillaries around the tubule -> venules -> renal vein
where is the glomerulus located
in bowman capsule
2 functions of kidney carried out by
the production of urine
composition of urine, water
96%