What is the effect of angiotensin II in the CNS as it relates to urinary sys.
Triggers release of ADH stimulating reabsorption of H2O & Na ions causing sensation of thirst
What is the effect of angiotensin II @ the adrenal gland?
Stimulates secretion of aldosterone by adrenal cortex & epi/norepi by adrenal medullae causing increase in systemic BP
At the kidney aldosterone stimulates . . . . .
Na reabsorption along DCT & collecting sys
What does renin do?
Part of the renin- angiotensin sys
Converts inactive angiotensinogen to angiotensin I which a converting enzyme activates angiotensin II
What is the renin-angiotensin system?
Causes release of renin by juxtaglomerular apparatus in response to low glomerular pressures due to decrease in blood volume, fall in systemic pressures or blockage of renal artery or its tributaries
What is secretion?
Transport of solutes out of peritubular capillaries, across tubular epithelium & into filtrate
Can further lower plasma concentration of undesirable materials
Why is secretion necessary?
B/c filtration does not force all dissolved materials out of blood
What is reabsorption?
Removal of water & solute molecules fr filtrate & their reentry into circulation @ peritubular capillaries
Occurs aft filtrate enters renal tubule
Describe process of reabsorption.
A selective process that involves simple diffusion or the activity of carrier proteins in the tubular epithelium
H2O reabsorption occurs passively thru osmosis
What is the primary purpose of urine production?
Maintain homeostasis by regulating vol & composition of blood
What 3 dissolved solutes are excreted with urine?
Urea
Creatinine
Uric Acid
What is Urea?
Organic waste created during breakdown of amino acids
What is creatinine?
Metabolic waste created in skeletal muscle thru breakdown of creatine phosphate
What is Uric Acid?
Metabolic waste created during breakdown & recycling of RNA
What is filtration pressure?
Around 10 mmHg
What is the Glomerular Filtration Rate?
Amt of filtrate produced in kidneys each minute
About 125mL/min
What is a minor calyx?
Cup shaped drain that ducts within the renal papilla discharge urine into
What makes up a major calyx?
4 or 5 minor calyces merged together
2 major calyces merge to form funnel shaped chamber or renal pelvis
What is the renal pelvis?
funnel shaped chamber made up of both major calyces
Connected to ureter thru which urine drains out of kidney
What is the hilum the site of?
Exit of ureter fr kidney
Place where renal artery & renal nerve enter kidney
Renal vein exits kidney
Where does the renal artery originate & go?
Starts @ abd aorta
Enters renal sinus & divides branches that supply interlobular arteries
The renal vein receives blood fr where?
Interlobular veins -> arcuate -> interlobar -> renal veins & out of the kidney
What are peritubular capillaries?
Network of capillaries that surround proximal & distal convoluted tubules
Provide route for p/u or delivery of substances reabsorbed or secreted by this portion of the nephron
What is the vasa recta?
Long, straight capillaries that parallel loop of henle deep into the medulla
What is the difference between juxtamedullary & cortical nephrons?
Juxtamedullary nephron structure is located mostly within the medulla where as a cortical is located within the cortex