Biology: Urinary System Flashcards
What are the competent of urinary system ?
kidneys
ureters
urinary bladder
urethra
What is the anatomy of the kidney ?
renal cortex (outer) medulla (middle) renal pelvis (inner) continuous with the ureter that leads into the bladder
What are the nephrons ?
the functional units of the kidney and extend from the cortex (glomerular filtration) into the medulla (filtrate re-absorption and urine concentration)
What are the components of the nephron ?
renal corpsucle = bowman’s capsule (glomerular cpasule) + glomerulus (bundle of capillaries) attached to the proximal convoluted tubule which leads into the descending limb of the loop of hence leading to the ascending limb extending to the distal convluted tubule emptying into the collecting duct and the renal pelvis
What happens at the renal corpuscle?
protein not filtered out and remains in the blood
What happens at the proximal convoluted tubule?
100% of glucose reabsorbed back into blood capillaries 2/3s of sodium and water reabsorbed
What happens in the descending limb?
only water is reabsorbed
What happens at the loop of henle?
sodium concentration is at its highest
What happens in the ascending limb ?
only sodium re-absorbed (e.g pumped out when aldosterone is released by the endocrine gland on the top of each kidney)
What happens in the distal convoluted tubule?
more sodium reabsorbed
What happens in the collecting duct?
if dehydrated (high osmotic pressure/solutes) antidiuretic is released by the pituitary gland and water is reabsorbed, otherwise urine remains dilute
What happens in the renal pelvis?
waste products excreted in urine: urea 50% of it and creatinine 100% of it
What is the blood flow in the kidney?
aorta- renal artery- arteries of kidney- afferent arterioles to glomerulus capillaries- efferent arteriole from glomerulus network of blood capillaries surrounding nephrons- veins of kidney- renal vein and inferior vena cava
