Kidney Flashcards
what is excretion
-the removal of waste products as a result of metabolic reactions(cellular processes)
-excretory organs are lungs, kidneys and skin
what is egestion
-the removal of undigested food from the digestive system through the anus
what is homeostasis
maintenance of a constant internal environment
what does urine contain
-urea
-other nitrogenous wastes
-salts (sodium, potassium)
-water
what is urine produced by
-kidneys
what is the function of the kidney
-excretion
-osmoregulation
-the kidney removes waste from our blood
-it also adjusts the amount of water and salt in the blood
-the kidney sends the waste to your bladder to be stored as urine
relevance of liver with urine
-this organ is responsible for breaking down excess amino acids from digested proteins to make ammonia. Too much ammonia is dangerous as it is very acidic, so it is converted to urea and sent to the kidneys
relevance of kidney with urine
-once urea has been formed in the liver it travels to the kidney. The urea is then filtered out along with water and other unneeded ions to form urine
relevance of the ureter with urine
-narrow tubes that carry urine from the kidney to the bladder
-These tubes are made out of smooth muscle
relevance of bladder with urine
-stores the urine it is distended
relevance of urethra with urine
-a tube that connects the bladder for the removal of urine(and semen in males) to the outside of the body
label kidney
google it mate
how does blood enter the kidney
-renal artery
how does blood exit the kidney
-renal vein
what is the cortex
-contains tiny blood vessels
-contains nephrons
-ultrafiltration occurs
what is the medulla
-contains nephrons and capillaries
-connects to renal pelvis
-osmoregulation (regulation of water)
what is the renal pelvis
connects kidney to ureter
what are the 6 parts of the nephron
-glomerulus
-bowman’s capsule
-proximal convoluted tubule
-loop of henle
-distal convoluted tubule
-collecting duct
define ultrafiltration
-small molecules and ions are filtered out of the blood under higher pressure, into the bowman’s capsule
define selective reabsorption
-molecules and ions which are required by the body are taken back from the nephro
how does the site of ultrafiltration work
-the blood in the glomerulus, and the fluid in the bowman’s capsule are separated by 2 layers of cell (capillary wall and wall of the capsule) In between the layers in the basement membrane
how does ultrafiltration work
-the blood is forced through the glomerulus under high pressure
-The size of molecules allowed to leave the blood depends on the following 3 filters: capillary wall, basement membrane and Bowman capsule wall
-water , glucose and other small molecules are allowed through, but cells and large proteins stay behind in the blood
-the fluid that enters the bowman capsule space is called the glomerular filtrate
-very high blood pressure can cause proteins to be forced into the bowman’s capsule and appear in urine
where does selective reabsorption occur
-proximal convoluted tubule
how does selective reabsorption work
-all of glucose molecules are reabsorbed from the filtrate back into the blood via active transport
how and where is water reabsorbed into the blood
osmosis in the loop of henle
define osmoregulation
maintaining a constant level of water and salts in the body
what is ADH
anti-diuretic hormone
what does ADH do
it is a substance that produces less urine
where is ADH secreted from
the pituitary gland
describe how ADH works
-dehydration
-decreased water potential in the blood
-osmoreceptor cells in the hypothalamus detect low water potential in blood
-hypothalamus stimulates the pituitary gland
-the pituitary gland secretes increased amounts of ADH
-ADH is secreted in the blood
-ADH arrives at the collecting duct, and causes it to become more permeable to water
-more water is reabsorbed into the blood. Therefore less urine is produced and it is more concentrated
