U R I N A R Y Flashcards
list pathway from collecting duct until leaving kidney
- collecting duct
- papillary duct
- renal pyramid
- minor calyx
- major calyx
- renal pelvis
- ureter
- urinary bladder
- urethra
structure and function of glomerulus
blood-filtering structure of the kidney, passive, glomerular mesengial cells
parietal & visceral layers
glomerulus parietal layer
outer structural layer, simple squamous
glomerulus visceral layer
podocytes (foot processes), capsular space; capillary endothelium, basement membrane, foot processes of glomerular capsule
which structures bring blood to and from the glomerulus and why is this particular blood vessel type good for the job?
afferent and efferent arterioles
protect glomerulus from fluctuation in BP, reinforce glomerular BP, decrease hydrostatic pressure of peritubular capillaries, high resistance to blood flow
describe the structure, location, and function of the macula densa
structure: tall, columnar, closely-packed cells
location: DCT
function: act as chemoreceptors that sense NaCl content of filtrate
trace blood flow through kidney beginning at renal artery
(aorta) 1. renal artery 2. segmental artery 3. interlobar artery 4. arcuate artery 5. cortical radiate artery 6. afferent arteriole 7. glomerulus (capillaries) 8. efferent arteriole 9. peritubular capillaries or vasa recta 10. cortical radiate vein 11. arcuate vein 12. interlobar vein 13. renal vein (inferior vena cava)
trace filtrate through nephron, starting with glomerular capsule
- glomerular capsule
- PCT
- descending thin limb
- thin ascending limb
- thick ascending limb
- DCT
- CD
- papillary duct
- minor calyx
- major calyx
- renal pelvis
hydrostatic pressure
push due to high BP
osmotic pressure
pull due to presence of plasma proteins
how does the kidney use renin to raise BP?
converted to angiotensin 2
- constricts arteriolar smooth muscle, causing MAP to rise
- stimulates the reabsorption of Na+
- acts directly on renal tubules and triggers adrenal cortex to release aldosterone (target at principle cells to reabsorb Na+) - stimulates hypothalamus to release ADH and activates the thirst center
- constricts efferent arterioles, decreasing peritubular capillary hydrostatic pressure and increasing fluid reabsorption
what 2 parts of the nephron are responsible for concentrating urine and how is this accomplished?
- collecting duct
- DCT
presence or absence of ADH & aquaporins
where to ADH and aldosterone act to affect urine concentration?
DCT & CD of kidney tubule cells (principle cells)
- facultative water reabsorption
how does aldosterone affect urine concentration?
- increases reabsorption of Na+
2. targets principle cells to insert Na+/K+ channels and pump (increases BP and decreases K+)
how does ADH affect urine concentration?
cause principle cells to insert aquaporins for increased water reabsorption
what substance is rarely found in filtrate in the renal tubules under normal conditions?
plasma proteins
would plasma proteins affect glomerular hydrostatic pressure most or osmotic pressure most?
osmotic pressure
ureter function
paired tubes that transport urine from the kidneys to the urinary bladder
urinary bladder function
temporary storage for urine
urethra function
tube that carries urine from urinary bladder to body exterior
major functions of the kidneys
regulate body’s total water volume (ADH) & total concentration of solutes in that water ( Aldosterone)
- regulate ion concentration in ECF
- long term acid/base balance (lungs)
- excrete metabolic wastes and foreign substances
- produce erythropoietin and renin
- convert vitamin D to its active form
- carry out gluconeogenesis during prolonged fasting
transport maximum (Tm)
for every reabsorbed substance, number carriers in renal tubules available for facilitated diffusion or cotransport mechanisms
- carriers saturated > excess excreted in urine (hyperglycemia)
- glucose in urine: glycosuria
excess glucose in urine holds water and more urine is excreted with glucose
- glucose in urine: glycosuria
renal threshold
the concentration of a substance dissolved in the blood above which the kidneys begin to remove it into the urine
GFR
vol of filtrate formed per minute by both kidneys
(normal: 120-125 ml/min)
GFR is directly proportional to:
- NFP
- total surface area available for filtration
- filtration membrane permeability
High BP = high GFR