Kidney Anatomy

imissyou419's version from 2017-03-29 13:16


Question Answer
Kidney functionsRegulation of ionic composition of blood,
regulation of blood pH,
regulation of blood volume,
regulation of BP,
maintenance of blood osmolarity,
production of hormones (Erythropoietin/EPO, activation of vitamin D called Calcitrol - steroid hormone receptor involved in changing gene expression),
regulation of blood glucose levels (kidney do gluconeogenesis),
excretion of wastes and foreign substances [urea (breakdown of a.a), uric acid (breakdown of nucleic acid), creatinine (breakdown of creatine energy carrier in skeletal muscle), urobilin (breakdown of RBC)]
One of the function of kidney is the production of ADHFalse, kidney does not produce ADH but respond to it (hypothalamus-posterior pituitary releases it)
One of the function of kidney is production of reninTrue, but renin is an enzyme NOT a hormone (produced by juxtaglomerular cells in response to low Na+ levels, renin cleaves angiotensinogen to ANG I then ACE cleaves ANG I to ANG II)
Renal pelvishollow section in every section of kidney, where urine collects (Calyces join to become this)
Calycesfunnels that collect from cortex and medulla, at bottom of medulla
Renal arteryblood supply to kidney tissue + processing
Renal veinblood exit after processing
Ureterurine travel to bladder
Which 2 organs get the most blood flow in ml/min?liver (filter, metabolize substances i.e. vitamin D) and kidney [gets more blood than all other tissue based on its size]
Nephronfilter, processing so urine put into renal pelvis is right solution
Afferent arteriole1 afferent arteriole supply each nephron, brings blood into renal corpuscle; can constrict/dilate to finely control blood flow
Renal corpusclehollow cavity filled with capillary bed (glomerulus) -> filtering component, receives blood via afferent arteriole, filtered blood is called filtrate; filtrate gets processed by rest of nephron
Common collecting ductwhere collecting ducts of other nephrons join
Efferent arterioleblood not filtered leave renal corpuscle; can constrict/dilate to finely control blood flow
Glomerulusfenestrated capillary bed made up of 1 layer of endothelial cells inside corpuscle allowing movement of blood into Bowman's space
What is the vasculature like in the kidney?renal artery -> afferent arteriole -> capillary bed (glomerulus) -> efferent arteriole -> capillary bed (peritubular capillary) -> renal vein
Peritubular capillariescapillary bed outside tubule, reabsorption
Cortical nephronsPredominant in humans, corpuscle sits further to surface of cortex, short LoH, peritubular capillary more twisted
Juxtamedullary nephronsLess common in humans, corpuscle sits "next to" medulla but still in cortex, long LoH, vasa recta capillary more parallel)
CortexGranulated (has corpuscles so give appearance of spots)
MedullaStriated (has LoH)
Bowman's capsucle cell typeoutside of renal corpuscle, made up of 1 layer of epithelial cells (simple squamous)
Bowman's space/Capsular spaceinside of renal corpuscle, blood filtered into this space
Podocytesspecialized epithelial cells wrap around glomerulus and has finger-like projections to prevent some fluid from filtering out, continous with Bowman's capuscle for "vacuum seal"
Juxtaglomerular apparatusascending limb of LoH wraps back and pass in between afferent and efferent arteriole (this apparatus is called juxtaglomerular apparatus and composes of tube, macula densa cells, juxtaglomerular cells, afferent & efferent arteriole)
Mascula densa cells
how does it detect flow?
cells within ascending limb of LoH that function like the rest of the tube, chemoreceptors that detect FILTRATE Na+ and Cl- with NKCC transporter, detect fluid flow with primary cilia that bend, release paracrine factors i.e. NO, ATP (cleaved to adenosine), prostagladins
Juxtaglomerular (granular) cellscells part of afferent arteriole, respond to signals from Macula densa cells to constrict/dilate afferent arteriole?
How does fluid pass through the 3 barriers of filtration?Fluid pass in between fenestrated (pores) endothelial cells of glomerulus, pass through basal lamina (adheres glomerulus to podocytes, mesh work of collagen/negatively charged glycoproteins), pass between podocytes
What in the blood can make it into Bowman's space?ions (both + and -),
hydrophilic metabolites,
glucose (small),
a.a (small)
What in the blood cannot make it into Bowman's space?proteins (too large and negatively charged so inhibited mostly by basal lamina),
RBC and WBC (too large)
- if these in urine, problem with barriers of filtration
Proximal tubule cell typecolumnar - microvilli (increase SA to maximize reabsorption), many mitochondria (metabolically active)
Descending limb of LoH cell typesimple squamous - less mitochondria (less metabolically active b/c reabsorb fewer substances from filtrate)
Collecting duct cells typecuboidal - mixed population of epithelial cells; principal predominant (responds to hormones that change how collecting duct functions), intercalated less (responds for balancing acid and bases, has microvilli to maximize SA)
Filtrationonly occurs in renal corpuscle
REabsorptionmoves item from filtrate back into body through tubule cells into surrounding vascular
Secretionitems that did not get a chance to be filtered secreted from peritubular capillary (through efferent arteriole route) into lumen of tubule i.e. get rid of drugs faster than just filtering it
Excretionfiltrate that gets collected in renal pelvis is now called urine (not secretion - secreted into lumen)


Question Answer
LeukocytesNo, WBC indicate infection
NitriteNo, metabolized by bacteria so indicate bacteria infection
UrobilinogenYes, metabolite/breakdown from hemoglobin
ProteinNo, should be repelled by basal lamina
pHshould be slightly acidic
HaemoglobinNo, indicate RBC is breaking down faster than it should
Specific gravityratio density of solute / water, gives you hydration level (if hydrated - low level, if dehydrated - high level)
KetoneNo, ketone acidosis indicate uncontrolled diabetes mellitus
BilirubinNo, should be excreted through bile duct system/intestines (from breakdown of RBC)
GlucoseNo, glucose reabsorbed
UreaYes, breakdown of a.a.
Uric acidYes, breakdown of nucleic acid
CreatinineYes, breakdown of creatinine energy carrier in skeletal muscle

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