Chapter 20: Urinary System Flashcards
vasa recta
important for exchange in nephron
what happens after filtrate leaves the glomerular capsule?
it enters the renal tubule
urine formation (formation steps)
- glomerulus
- glomerular capsule
- proximal tubule
- descending loop
- ascending loop
- distal tubule
- collecting duct
urine formation (excretion)
- minor calyx
- major calyx
- renal pelvis
- ureter
- urinary bladder
urine formation (elimination)
urethra
2 types of nephrons in kidney
- cortical
- juxtamedullary
cortical nephrons
sit high in cortex, with short nephron loops
juxtamedullary nephrons
sit low in cortex, with long nephron loops; important in regulating water & urine concentration
juxtaglomerular apparatus
- regulates secretion of renin
- transportation of ascending limb of nephron loop of each nephron passes between afferent & efferent
- ascending limb comes in contact with afferent to form apparatus
renin
plays role in blood pressure production
RAA system
renin angiotensin aldosterone system
macula densa
tall, closely packed cells of ascending limb
juxtaglomerular cells
large, smooth muscle cells of afferent arteriole
what regulates the renin angiotensin system?
renin secreted by juxtaglomerular apparatus; increases blood pressure
what does urine contain?
- wastes
- excess water
- electrolytes
3 processes of urine filtration
- glomerular filtration
- tubular reabsorption
- tubular secretion
glomerular filtration
- first step
- substances move from blood to glomerulus unto the glomerular capsule
- large molecules remain in the blood due to size
- glomerular capillaries are many times more permeable than other capillaries due to fenestrae
fenestrae
tiny slits or pores in capillaries
glomerular filtrate
similar composition to tissue fluid
causes of protein in urine
- starvation
- kidney failure
- kidney disease
- high protein diet
