Exam 4 Renal Phys Flashcards
(33 cards)
What is the kidneys function as an excretory organ
Excretes harmful substances and things that are in excess
How does the kidney function as a regulatory organ
Maintains constant volume, composition and regulate pH
How does the kidney act as an endocrine organ
Synthesizes and secretes at least 3 major hormones (renin, erythropoietin, 1,25 dihydroxycholecalciferol)
What is the function of renin secreted by the kidney
Stimulates angiotensin II formation and aldosterone secretion
What is the function of erythropoietin released by the kidneys
Stimulates red blood cell production
What is the function of 1,25 dihydroxycholecalciferol
Widespread effects including Ca++ absorption from the GI tract
How does the kidney function in electrolyte balance
Water intake =output, sodium intake = output, sodium/potassium balance
What are the 3 main renal functions
Electrolyte balance, concentrating urine, dilute urine
Aside from calcium uptake what are other roles of 1,25 dihydroxycholecalciferol
Enhance immune function (preventing atopic disorders) aka vitamin D3/calcitriol
How much glucose does the kidneys reabsorb per day
180 g of D-glucose/day
When is gluconeogenesis more active within the renal functions
During periods of prolonged fasting
Where is glucose filtered
Reabsorption of virtually all filtered glucose in the PCT
Where are the kidneys located
L1-L4 retroperitoneal
Where does the kidney receive pregang symp fibers from
T10 -L2
What is the role of postgang symp fibers on the kidney
Project via renal plexus around renal artery
What happens when postgang symp fibers project to individual nephrons
Stimulation resulting in signal to constrict arterioles decreasing filtration and output, also signal for increase in Na reabsorption/renin release
What is the blood supply from cardiac output to the kidneys
22% of CO under resting condtion
Why does renal blood supply have a unique blood flow
2 sets of capillary beds and 2 sets of arterioles in series
What gives rise to glomerular capillaries
Afferent arterioles
What do efferent arterioles do and what do they give rise to
They drain the glomerular capillaries and give rise to peritubular capillaries
Where does all filtration take place
Glomerular capillaries
Where does all reabsorption take place
Peritubular capillaries
What keeps glomerular capillary filtration pressure constant
Efferent arteriole
What type of pressure is in the glomerular capillaries
High hydrostatic pressure (45mmHg) kept constant by efferent arteriole
