Topic L- Execretion Flashcards
definition of excretion
removal of waste products of a chemical reaction
definition of egestion
removal of left over substances or unused material ( which hasn’t been part of a chemical reaction)
Name 3 excretory organs
Kidneys
Lungs
Skin
what do lungs excrete
carbon dioxide
what does skin excrete
sweat
what doe the kidneys excrete
urine = urea
ions ( salt)
water
where is urea produced and from what
in the liver from excess amino acids
what parts are contained within the urinary system
7 things
Vein Artery Kidneys Ureters Bladder Sphincter muscle Urethra
PAPER 2
describe structure of a nephron
8 things
Renal artery Glomerulus Bowman's capsule Proximal convoluted tubule Loop of Henle Distal convoluted tubule Collecting duct Blood to renal vein
PAPER 2
ultrafiltration in bowman’s capsule
- blood from renal artery flows through glomerulus
- High pressure = water, urea, ions + glucose (glomerular filtrate ) squeezed out of blood into Bowman’s capsule
- Membrane between blood vessels in glomerulus and bowman’s capsule = filters= proteins + blood cells ( big molecules not squeezed out but remain in blood.
PAPER 2
what is the filtered liquid in the Bowman’s capsule known as
glomerular filtrate
PAPER 2
what is glomerular filtrate composed of
water
urea
ions
glucose
PAPER 2
what happens at the collecting duct
water is reabsorbed from the collecting duct into the bloodstream by osmosis
PAPER 2
what happens at the proximal convoluted tubule
all the glucose reabsorbed from the proximal convoluted tubule back in to blood stream by active transport
PAPER 2
why does reabsorption of glucose occur at the proximal convoluted tubule
so the glucose can be used in respiration
PAPER 2
what does selectively reabsorbed mean
only some substances are reabsorbed
PAPER 2
definition of osmoregulation
body constantly controlling the balance of water coming in against the water going out
PAPER 2
how is water taken into the body
food + drink
PAPER 2
how is water lost from the body
sweating
breathing
weeing
PAPER 2
what does ADH stand for
anti-diuretic hormone
PAPER 2
what does the hormone ADH do
controls the amount of water reabsorbed in the kidney nephrons
PAPER 2
how is the hormone ADH released
brain monitors the water content of blood and instructs pituitary gland to release ADH into the blood
PAPER 2
what happens if we don’t have enough water
Brain detects water loss= pituitary gland..
More ADH= More water reabsorption= Less urine
PAPER 2
what happens if we have to much water
Brain detects water gain= pituitary gland..
Less ADH= Less water reabsorption= More urine
PAPER 2
what happens to urine when the kidneys reabsorb more water
urine= smaller volume + more concentrated
PAPER 2
what does urine contain
water
urea
ions (salts)
PAPER 2
what are nephrons
filtration units in the kidneys
PAPER 2
definition of ultrafiltration
substances filtered out of the blood from glomerulus into Bowman’s capsule
PAPER 2
where does selective reabsorption take place and of what
proximal convoluted tubule
glucose
PAPER 2
where does ultrafiltration take place
Bowman’s capsule
PAPER 2
what happens at the loop of henle
alters salt concentration in medulla = aid water reabsorption from collecting duct
PAPER 2
where does variable reabsorption of water take place
collecting duct
PAPER 2
what does ADH specifically do
increases permeability of collecting duct
