what organs make up the urinary system?
one urinary bladder
What is the function of the kidneys?
1-regulation of blood ionic composition
2-regulation of blood pH
3-regulation of blood volume
4-regulation of blood pressure
5-regulation of blood glucose
6-maintenance of blood osmolarity
7-production of hormones
8-excretion of waste & foreign substances
what ions do the kidneys regulate?
sodium ions (Na+)
chloride ions (Cl-)
phosphate ions (HPO4--)
what are the two ions that regulate blood pH?
hydrogen ions (k+)
bicarbonate ions (HCO3-)
how do the kidneys regulate blood volume?
by conserving or eliminating water in the urine
what enzymes are important for regulating blood pressure?
enzyme renin which regulates the renin-angiotensin-aldosterone pathway
how does the kidney regulate blood osmolarity?
by separately regulating the loss of water and the loss of solutes
what is the osmolarity of blood?
about 300 milliosmoles per liter
what two hormones do the kidneys produce?
calcitriol and erythropoeitin
what waste products does the kidney excrete?
ammonia & urea from deamination of amino acids
bilirubin from catabolism of hemoglobin
creatinine from creatine phosphate in muscle
which organs are retroperitoneal?
kidneys, ureters and bladder
what structures define trigone?
2 ureters and 1 urethra
what does the term micturition mean?
emptying urine from bladder
how is urine moved through the ureters?
one of three ways
which kidney is inferior in location?
the right kidney
what are the 3 layers that cover the kidney?
2-adipose capsule-middle layer
3-renal fascia-outer-most layer
what percent of people have cortical nephrons?
what percent of people have a juxtamedullary nephron?
what is the histology of loop of henle?
simple cuboidal to low columnar cells
what is the histology of macula densa cells?
columnar tubule cells
what is the histology of juxtaglomerular cells?
modified smooth muscle cells
what structures make up the filtration membrane?
glomerular capillaries and podocytes
what are mesangial cells?
contracting cells that regulate glomerular filtration
what is the juxtaglomerular apparatus?
macula densa cells and juxtaglomerular cells that regulate blood flow into the glomerulus
what is the function of principal cells?
to control the concentration of urine via ADH and aldosterone receptors
what is the function of intercalated cells?
help homeostasis of blood pH
what are the 3 function of the nephron?
what are the 3 filtration membranes in the glomerulus?
1-fenestrations- prevents filtration of blood cell
2-basal lamina- prevents filtration of large proteins
3-slit membrane between pedicels-prevents filtration of medium sized proteins
why is the volume of fluid filtered by the renal corpuscle much larger than other capillaries?
1-larger filtration surface
2-filtration membrane is thin and porous
3-high blood pressure in glomerulus
what are the three pressure responsible for net filtration?
GBHP, CHP and BCOP
define net filtration
the total pressure that promotes filtration
what is the typical NFP?
what are the three mechanisms that regulate GFR?
what are the two sub-mechanisms in autoregulation?
1-myogenic regulation-stimulated by blood pressure
2-tubuloglomerular feedback system-increase of GLR via increase of Na+, Cl
what is the function of nitric oxide? (NO)
an increase in nitric oxide dilates arteriole
a decrease in nitric oxide constricts arteriole
describe neural regulation
sympathetic nerves release norepinephrine which constricts afferent arteriole via alpha receptors and release of renin
describe hormonal regulation of GFR
angiotensin II reduces GFR and ANP increases GFR
what are the two reabsorption routes?
2-transcellular-through the cells
what are the two transport mechanisms for solutes?
primary active transport and secondary active transport
how does ADH regulate water reabsorption?
increase water permeability in principal cells
how does ANP regulate reabsorption and secretion?
increase capillary surface area for filtration