Chapter 25 Flashcards
Nephrons
structural and functional units that form urine
Two parts of nephrons
renal corpuscle and renal tubule
What do urinary medications focus on?
Loop of Henle
Glomerulus
capillaries are specialized for filtration
Afferent arteriole
enters glomerulus
Efferent arteriole
leaves glomerulus
Vasa recta
function in formation of concentrated urine
Juxtaglomerular complex
regulating rate of filtrate formation and blood pressure
Three processes involved in urine formation
Glomerular filtration, tubular reabsorption, tubular secretion
Glomerular filtration
passive process
Filtration membrane
hydrostatic pressure forces fluid and solutes through
Hydrostatic pressure in glomerular capillaries
essentially glomerular blood pressure
What is the chief force pushing water, solutes out of blood?
hydrostatic pressure
High-resistance vessel
efferent arteriole has a smaller diameter than afferent ateriole
GFR
volume of filtrate formed per minute by both kidneys
What does GFR affect?
systemic blood pressure
increased GFR causes
increase urine output = lower blood pressure
Goal of extrinsic controls
maintain systemic blood pressure
Renin-angiotensin-aldoesterone mechanism
main mechanism for increasing blood pressure via sympathetic nervous system
Tubular reabsorption
quickly reclaims most of tubular contents and returns them to the blood
Substances can follow two routes
transcellular and paracellular
What is the most abundant cation in filtrate?
Na+
What creates the osmotic gradient for water?
movement of Na+
Proximal convoluted tubule
almost all uric acid
Nephron loop
descending and amending limbs
Descending limbs
H2O can leave, solutes cannot
Ascending limb
H2O cannot leave, solutes can
Distal convoluted tubule and collecting duct
reabsorption is hormonally regulated in these areas
Aldosterone
targets collecting ducts and distal DCT
-promotes Na+ reabsorption
Atrial natriuretic peptide
reduces blood Na+ leads in decreased blood pressure
Chemicals that enhance urinary output
ADH inhibitors, such as alcohol
Layers of bladder wall
mucosa, muscular layer, fibrous adventitia
