1 Renal Anatomy & Histology Flashcards
1
Q
General functions of the kidney
- Most important
- Excretion
- Responsibilities
- Filtration
- Reabsorption
- Secretion
- Endocrine
- Metabolic
A
- Most important
- Maintain salt & water balance (aqueous homeostasis)
- Excretion
- Responsibilities
- Form urine
- Remove metabolic wastes
- Balance internal ion concentrations
- Eliminate exogenous substances (drugs, pesticides, & other chemicals)
- Filtration
- Passive process based on size & charge of plasma components
- Removal of breakdown products of protein metabolism
- Occurs in glomeruli
- Reabsorption
- Retention of essential substances (water, glucose, amino acids, sodium, bicarbonate) from the filtrate back into the blood
- Occurs in the tubules
- Secretion
- Cellular transport into the tubular lumen of substances/drugs too large or charged to enter the filtrate of the glomerulus
- Ex. penicillin, contrast dyes
- ATP binding cassette (ABC) trasnporters shuttle lipophilic substances across tubular membranes
- Cellular transport into the tubular lumen of substances/drugs too large or charged to enter the filtrate of the glomerulus
- Responsibilities
- Endocrine
- Kidney releases secretions into circulation
- –> systemic effects
- Renin –> retain Na & water
- Erythropoietin –> RBC maturation
- –> local effects
- Prostaglandins & kinins affect local blood flow through the kidney
- Metabolic
- Peptide hormone degradation (PTH, insulin)
- Vitamin D –> 1,25 dihydroxyvitamin D3 (active form)
- Hypoglycemia –> gluconeogenesis
- Citrulline –> arginine as urea cycle processes NH4
- All components of the uric cycle except the last step (arginase enzyme) so citriulline –> arginine
- Severe kidney disease: arginine –> essential amino acid
2
Q
Light microscopy
- H&E
- PAS
- Mallory’s trichrome stain
- Silver stain
A
- H&E
- Highlights overall kidney morphology (rare)
- PAS
- Highlights thickness of basement membrane & ECM
- Bright pink = proteoglycans / carbohydrates
- Mallory’s trichrome stain
- Highlights degree of collagen deposits in interstitial matrix
- Blue = collagen I (& II & III)
- Silver stain
- Highlights fine collagen III in the matrix
- Black = collagen III (reticulin fibers)
3
Q
Electron & immunofluorescence microscopy
A
- EM
- Ultrasound that looks at the glomerular filtration membrane
- For diagnosis (esp glomerular disorders)
- IM
- Antibodies labeled w/ fluorescein bind to immunoglobulins (ex. IgG, IgA), C3, or C4 which may accumulate in certain renal pathologies
- IM visualizes the locaiton of these molecules
4
Q
Renal biopsy
A
- 4 phsycial elements / histological areas examined for involvement in disease processes
- GLomeruli
- Tubules
- Interstitium
- Blood vessels
- Visible interstitium –> too much (normally souldn’t see)
- Enlarged blood vessels –> renal vascular disease
5
Q
Gross histology (A-Q)
A
- A: Capsule
- Thick, strong, w/ capsular veins
- B: Hilus
- Blood vessel entrance/exit
- Ureter exit
- C: Renal artery & vein
- D: Cortex (outer)
- W/ glomeruli & tubules
- Darker reddish brown due to richer blood supply
- E: Medulla (inner)
- W/ straight tubules
- Shaded zones due to thickness of tubules
- F: Medullary rays
- Bundles of straight tubules in cortex which travel to & from the medulla (not part of the medulla)
- G: Medullary pyramids
- Conical shaped w/ their apex toward the renal hilus
- Lighter & striated appearance
- H: Renal papilla
- Apex of the renal pyramid
- I: Renal lobes
- Medullary pyramid + cap of cortex (8-14 in humans)
- Interlobar arteries
- J: Renal lobules
- Medullary ray + associated nephrons
- Interolobular arteries
- K: Minor calyx (8-14)
- Receives tips of each medullary lobe
- L: Major calyx (3-4)
- Receives tips of minor calyces
- Empties into the renal pelvis
- M: Renal pelvis
- Continuous w/ ureter
- Once urine gets here, we lose the capacity to make alterations to the urine
- N: Nephron
- O: Interlobular artery
- P: Arcuate artery
- Q: Ureter
6
Q
Nephron
- Bowman’s capsule
- Proximal tubule
- Thin limbs of the loop of henle (descending & ascending)
- Thick ascending limb of the loop of henle
- Distal convoluted tubule
- Collecting duct
- Number of nephrons
- Classification
A
- Bowman’s capsule
- Associated w/ the glomerulus (a tuft of capillaries) –> filtration
- Proximal tubule
- Integrated w/ peritubular capillaries –> reabsorption & secretion
- Thin descending, thin ascending & thick ascending limbs of the loop of henle
- Interaction w/ surrounding vasa recta –> hypertonic interstitium for altering the tonicity of excreted urine
- Distal convoluted tubule
- Integrated w/ peritubular capillaries for reabsorption & secretion
- Collecting duct
- Close association w/ the vasa recta –> final assimilation of water & ions from the urine back to the blood
- Number of nephrons
- ~1 million per kidney
- Classification
- Based on the location of the glomerulus (filtration unit)
- Superficial: outside
- Juxtamedullary: inside (near the medulla)
- Midcortical: in between
- Based on the length of the loop of henle
- Short loop: superficial
- Long loop: juxtamedullary
- Based on the location of the glomerulus (filtration unit)
7
Q
Glomerulus
- Function
- Location
- Components
- Vascular pole
- Urinary pole
- CO, filtrate, & excreted urine
A
- Function
- Filtration unit of the kidney
- aka renal corpuscle
- Location
- Cortex
- Surrounded by coiled tubules
- B/n medullary rays
- Components
- Blood vessels (glomerular capillaries)
- Epithelium of the nephron tube (bowman’s capsule)
- Intervening basement membrane b/n the endothelial layer of capillary & bowman’s capsule
- Stalk of intraglomerular support cells (mesangial cells)
- Vascular pole
- Entering afferent arteirole & exiting efferent arteriole cluster here
- Urinary pole
- Continuation of the nephron tubule exits the glomerulus here
- CO, filtrate, & excreted urine
- ~20% of blood volume leaving the heart (CO) is filtered through the kidney (1 L/min of the total CO of 5 L/min)
- Kidneys produce 180 L of filtrate / day but only excrete 1-2 L urine / day
8
Q
Glomerulus: blood vessels
- Afferent arteriole
- Capillary endothelium
- Efferent arteriole
- Both arterioles
- Portal system
A
- Afferent arteriole
- Incoming, larger
- Branches to form a tuft of glomerular capillaries where filtration ocurs
- Capillary endothelium
- Fenestrated w/ no diaphragms spanning the pores
- Capillaries are riddled w/ holes in endothelial cells
- Gaps keep cellular elements out but can let large proteins in based on damage
- Patent capillary loops: histological landmark where filtration occurs
- Fenestrated w/ no diaphragms spanning the pores
- Efferent arteriole
- Outgoing, smaller
- Formed from merged glomerular capillaries
- Both arterioles
- Surrounded by smooth muscle that contracts & relaxes to affect filtration pressure in the glomerular capillaries
- Portal system
- 2 capillary beds + 1 loop of circulation
- Occurs in the liver, kidney, & pituitary
9
Q
Glomerulus: bowman’s capsule
- General
- Parietal epithelium
- Visceral epithelium
- Vascular pole
- Urinary pole
A
- General
- Blind beginning of tne nephron tube
- Bulbous expansion
- Parietal epithelium (outermost)
- Simple squamous epithelium
- Forms the outer wall of the urinray space
- Where provisional urine accumulates
- Visceral epithelium (innermost)
- Reflects over the glomerular tuft of capillaries
- Coats capillaries
- Vascular pole
- Parietal epithelium is continuous w/ the visceral epithelium
- Where incoming afferent arterioles, capillaries, & efferent arterioles exist
- Urinary pole
- Parietal epithelium is continuous w/ the proximal tubule
- Where extra filtrate exits
10
Q
Glomerulus: podocytes
- General
- Foot processes (pedicels)
- Filtration slit diaphragm
- Nephrin
- Intracellular linkage molecules
- Minimal change disease
A
- General
- Specialized cells that form the visceral epithelium of bowman’s capsule that covers glomerular capillaries
- 2 podocyte cells coat capillaries
- Foot processes (pedicels)
- Formed by podocyte processes or trabeculae interdigitating w/ processes from neighboring podocytes
- Coated w/ podocalyxin (a glycoprotein rich in negatively charged sialic acid)
- Provides repulsion b/n adjacent podocytes
- Spacing is essential for proper glomreular filtration
- Fusion of adjacent pedicles only occurs in pathologcial states
- Filtration slit diaphragm
- Specialized juncitonal complex that spans spaces b/n foot processes
- Nehprin
- Transmembrane protein of the immunoglobulin superfamily (ex. cadherins)
- Forms homodimers to link neighboring foot processes
- Maintains podocyte integrity to regulate filtration
- Ca depending binding
- Actin: fibers that nephrins connect to
- Intracellular linkage molecules
- Interface b/n nephrin & actin cytoskeleton
- Ex. ZO-1, alpha-actinin4, podocin
- Minimal change disease
- 3 hallmarks: diffuse loss podocyte foot processes, vacuoles, microvilli
- Foot process fusion
11
Q
Glomerulus: basement membrane
- General
- 3 layers
- Interna & externa
- Diabetes
A
- General
- 320-33 nm thick
- Lies b/n the glomerular capillary endothelium & the podocyte foot processes
- 3 layers
- Lamina rara externa: contacts glomerular podocytes
- Lamina densa: central dense layer
- Collagen IV limits porosity of the BM to small substances
- Some albumin can get through (anything smaller: yes, anything larger: no)
- Lamina rara interna: contacts capillayr endothelium
- Interna & externa
- Contain anchoring proteins laminin & fibronectin + heparan sulfate-rich anionic proteoglycans
- Laminin: linker molecule b/n collagen, proteoglycans, & integrins found in all layers except right underneath filtration slit membranes
- Repel negativley charged plasma proteins (anions)
- Allow positivley charged proteins (cations) to pass through more easily
- Contain anchoring proteins laminin & fibronectin + heparan sulfate-rich anionic proteoglycans
- Diabetes
- Decrease in BM heparan –> proteinuria
12
Q
Glomerulus: filtration barrier
- 3 layers that comprise the glomerular filtration barrier
- Factors that determine glomerular filtration rate (GFR) through these layers
- Histological structures that fine tune GFR
A
- 3 layers that comprise the glomerular filtration barrier
- Fenestrated endothelium
- Glomerular basement membrane
- Foot processes w/ filtration-slit diaphragm
- Factors that determine glomerular filtration rate (GFR) through these layers
- Hydrostatic pressure: BP within the glomerular capillaries
- Oncotic pressure: created by plasma proteins
- Histological structures that fine tune GFR
- Smooth muscle in the media of afferent & efferent arterioles
- Contractile intraglomerular mesangial cells
13
Q
Glomerulus: intraglomerular mesangial cells
- General
- Smooth muscle-like mesangial cells
- Bone marrow-derived macrophages
- Glomerular sclerosis
A
- General
- Connective tissue cells that support the tuft of capillaries
- Smooth muscle-like mesangial cells
- Contractile (express alpha-actin) –> decreaes surface area for filtration
- Sensitive to AII –> constrict cells –> limit area for filtration
- Synthesize & degrade extracellular matrix components
- Collagen: mainly IV & V, more I & III when activated by cytokines
- Fibrinonectin, thrombospondin, laminin, vitronectin, proteoglycans
- Synthesize enzymes for turnover of ECM
- Metalloproteinases, serine-proteinases
- Secrete prostaglandins –> vasodilate glomerular arterioles –> counteract AII
- Secrete & sensitive to hormones, cytokines, growth factors, & paracrine agents
- Bone marrow-derived macrophages
- Phagocytose apoptotic cells in the basement membrane
- Utilize C3b or Fc receptors to bind opsonized particles
- Express MHC class II antigens –> act as antigen presenting cells
- Phagocytose apoptotic cells in the basement membrane
- Glomerular sclerosis
- Normal glomeruli: minimal intraglomerular mesangial CT
- Glomerular sclerosis: increased mesangial expansion at the expsne of open capillary loops
14
Q
Proximal tubule
- General
- Osmoticity of absorption
- Physiological segments
- Anatomical segments
A
- General
- First portion after leaving bowman’s capsule
- Reabsorptive workhorse
- Reabsorbs…
- All gluocse, amino acids, citrate, & small peptides
- Most water, Na, K, bicarbonate, Ca, & PO4
- Osmoticity of absorption
- Isomotic: absorptoin of solutes is proportional to that of water
- For any solute that is reclaimed, water can come w/ it
- Physiological segments
- Based on the distribution of transporters: S1, S2, & S3
- Anatomical segments
- Proximal convoluted tubules: coil & occupy most of hte cortex around glomeruli
- Proximal straight tubules
- In the cortex: in a medullary ray
- In the medulla: by itself
15
Q
Proximal tubule: histology
- Lining
- Lumen
- Peritubular capillaries
A
- Lining
- Simple cuboidal epithelium w/ a large, central, prominent nucleus
- Lumen
- Collapsed & star-shaped w/ fuzzy edges
- Peritubular capillaries
- Carmmed into spaces b/n tubules
16
Q
Proximal tubule: apical plasma membrane
- Brush border
- Apical tight junctions & desmosomes
- Junctional complexes
- Claudins
- Aquaporins
- Megalin
A
- Brush border
- Tall, regular microvili that increase surface area
- Carriers are inserted for secondary active transport of reabsorbed amino acids, glucose, citrate, & bicarbonate
- Molecules are coupled w/ Na in positively charged carrier complexes
- Apical tight junctions & desmosomes
- Tight junctions aka zonula occludens
- Less frequent & thinner than in other tissues
- Junctional complexes
- Provide large pores for water to go through freely
- Claudins
- Create leaky epithelium in tight junctions to permit paracellular movement of water & Ca from the lumen to the interstitial space below the epithelium
- Aquaporins
- Water channels for water to move through the apical membrane
- Megalin
- Wedge of small vesicles w/ different shapes & sizes
- Clathrin-mediated receptor anaglogous to the LDL receptor
- Binds to amino acids & small peptides to clear small peptides
17
Q
Proximal tubule: apical cytoplasm
- Endocytic apparatus
- Megalin
- Inhibition
A
- Endocytic apparatus
- Consists of vesicular invaginations b/n the bases of microvilli, clathrin coated vesicles, large vacuoles, lysosomes, & condensing vacuoles
- Here, peptides from teh filtrate are endocytosed & degraded before release outside the basolateral aspect of the cells
- Megalin
- Specific endocytosis receptor for albumin & small proteins recovered in the proximal tubule
- Clathrin-mediated receptor analogous to the LDL receptor
- Wedge of small vesicles w/ different shapes & sizes
- Binds to amino acids & small peptides to clear small peptides
- Specific endocytosis receptor for albumin & small proteins recovered in the proximal tubule
- Inhibition
- TGF-beta downregulates meglain during inflammatory conditions contributing to proteinuria
- Inhibitors of 3-hydroxy-3 methylglutary-CoA (statins) also inhibit this & endocytosis & can contribue to proteinuria
18
Q
Proximal tubule: basolateral plasma membrane
- Na/K ATPase
- Mitochrondia
A
- Na/K ATPase
- Extensive folding provides surface area for Na/K ATPase transporters
- Na/K ATPase pumps Na out of the cell & into the basolateral extracellular space
- Na electrochemical gradient powers secondary active transport at the apical border
- Cytoplasmic mitochondria
- Occupy folds b/n basolateral invaginations providing ATP for the energy demands of active transport
19
Q
Loop of henle
- 4 portions
- Length
- Interstitium tonicity
A
- 4 portions
- Thin descending limb
- Thin ascending limb
- Medullary thick ascending limb
- Cortical thick ascending limb
- Length
- Varies w/ location
- Short loops: superficial glomeruli
- Long loops: juxtamedullary glomeruli
- Extend to the tips of the medullary papillae
- Interstitium tonicity
- long LOHs establish a hypertonic interstitium in the medulla to produce hypertonic urine
- Countercurrent exchange b/n the tubules & vasa recta establishes & maintains the hypertonic interstitium
- 13% of nephrons contain long LOHs to produce hypertonic urine
20
Q
Loop of henle: thin descending limb
- General
- Permeability
- Water movement
- Tubular fluid
A
- General
- Simple squamous epithelium
- Variations in the # of interdigitations & mitochondria
- Permeability
- Permeable to water & urea (passive process)
- Impermeable to Na & Cl
- Water movement
- Water & urea passively move from the tubular fluid into the interstitium as the thin limb descends into the hypertonic interstitium of the medulla
- Water moves paracellular through shallow tight junctions & intracellularly through aquaporin channels
- Tubular fluid
- In equilibrium w/ interstitial mileu throughout its descent
21
Q
Loop of henle: thin ascending limb
- Main function
- Permeability
- Salt movement
- Water movement
- Active transport of Na or Cl
A
- Main function
- maintain & stabilize the hyperotnic gradient of the medullary interstitium
- Permeability
- Permeable to Na & Cl (passive process)
- Impermeable to water
- Salt movement
- Salt exits the tubule as flow ascends into less hypertonic regions of the medulla
- Water movement
- Water movement is prevented by more extensive tight junctions w/ claudins that seal & the lack of aquaporins
- Active transport of Na or Cl
- No active transport of Na or Cl anywhere laong the thin limb of the LOH
22
Q
Loop of henle: thick ascending loop (TAL)
- Location
- Tonicity
- Basolateral plasma membrane
- Mitochondria
- Apical plasma membrane
- Net result
- Inhibition
A
- Location
- Near the hairpin turn in short looped nephrons
- At the transition from the outer to inner medullayr zones in long looped nephrons
- Tonicity
- TAL aka diluting segment b/c the lumenal contents are hypotonic when they exit
- Basolateral plasma membrane
- Simple cuboidal epithelium displays numerous invaginations
- Folds extend almost to the apical end of TAL cells
- Site of Na/K ATPase active transport pumps
- Mitochondria
- Contained within cytoplasm b/n the folds
- More round than the elongated ones of the proximal tubule
- Apical plasma membrane
- Slightly irregular
- Contains a Na/K/2Cl symporter
- Extensive tight junctions block the paracellular movement of water
- No aquaporin channels –> impermeable to water
- Claudins permid passage of Mg, Ca, & Na
- Net result
- Movement of Na & Cl from the lumen into the interstitium
- Ion pumping produces the hypertonic medulary interstitium & delivers hypotonic, dilute tubular fluid to the distal convoluted tubule
- Inhibition
- Loop diuretics (ex. furosemide) inhibit the apical co-transporter
23
Q
Loop of henle: macula densa
A
- Last segment of the cortical TAL
- Each macula densa returns to its glomerulus of origin
- Component of the juxtaglomerular apparatus that’s responsible for renin secretion
24
Q
Distal convoluted tubule
- Location
- Length, lining, coiling, & tight junctions vs. proximal tubules
- Apical surface
- Basolateral surface
- Response to aldosterone & parathyroid hormone (PTH)
A
- Location
- In the cortex intermingled w/ the proximal convoluted tubules
- Length, lining, coiling, & tight junctions vs. proximal tubules
- Length: shorter w/ fewer sections per area
- Lining: lower cuboidal epithelium
- Coiling: not as much b/c doesn’t do as much work
- Tight junctions: broader w/ sealing claudins to prevent paracellular water movement
- Apical surface
- Devoid of microvilli –> smooth lumen
- Basolateral surface
- Highly folded w/ Na/K ATPase pumps & mitochondria
- Pumps drive reabsorption of Na & Cl
- Response to aldosterone & parathyroid hormone (PTH)
- Aldosterone: reabsorb Na
- PTH: reabsorb Ca
25
Q
Collecting duct
- 3 segments
- Function
- Under the control of…
- Lining
- Principal (light) cells
- Intercalated (dark) cells
A
- 3 segments
- Connecting segment
- Cortical collecting duct
- Medullary collecting duct
- Function
- Final adjustments to volume & tonicity of excreted urine
- Under the control of…
- Vasopressin (antidiuretic hormone, ADH)
- Aldosterone
- Lining
- Initially: simple cuboidal epithelium
- Toward the medullary papilla: tall, columnar, & pseudostratified at the exiting papillary ducts
- Full length: distinct lateral cell borders
- Principal (light) cells
- Pale cytoplasm, small random mitochondria, few basal infoldings, few microvilli, & a single cilium
- Cilium: flow sensor linked to a Ca channel
- Response to aldosterone: reabsorb Na & secrete K
- Response to ADH: increase luminal permeability to wtaer
- Intercalated (dark) cells
- More electron dense
- Secrete H for acid/base balance & urine acidification
26
Q
Juxtaglomerular apparatus
- Where it fits in w/ the other parts of the nephron
- Function
- Structures
- Sensors
A
- Where it fits in w/ the other parts of the nephron
- Proximally: reabsorb filtrate
- Distally: fine-tuning
- In b/n: juxtaglomerular apparatus provides feedback about what the nephron is doing
- Function
- Control GFR to not flood out the capacity of the distal nephron
- Prevents excessive salt & water loss
- Adjusts renal hemodynamics during increased or decreased perfusion
- Activates renin, AII, & aldosterone
- Structures
- Afferent arteriole
- Efferent arteriole
- Macula densa
- Extraglomerular mesangial cells
- Sensors
- Afferent arteriole stretch receptors
- Macula densa Cl/osmolality receptors
27
Q
Juxtaglomerular apparatus: juxtaglomerular (JG) cells in the afferent arteriole
A
- Specialized cells that comprise smooth muscle in the media
- Contain intracellular actin, myosin, dense bodies, RER, golgi, & secretory vesicles
- Decrease BP –> decrease arteriorlar stretch –> JG cells secrete renin
- Increase BP –> JG cells vasoconstrict the AffA
28
Q
Juxtaglomerular apparatus: macula densa
- Location
- Base
- Nuclei
- Response to flow related alterations in levels of Cl (osmolality) in the fluid being delivered from the thick ascending limb
A
- Location
- Where the cortical thick ascending limb returns to its glomerulus of origin
- Base
- Interdigitate w/ underlying extraglomerular mesangial cells & JG cells
- Nuclei
- Forced apically toward the luemn
- Response to flow related alterations in levels of Cl (osmolality) in the fluid being delivered from the thick ascending limb
- High Cl flow rates –> high glomerular perfusion rate –> macula densa releases adenosine & NO (directly) & AII & thromboxane (indirectly) –> blocks JG cell renin release
30
Q
Juxtaglomerular apparatus: efferent arteriole
A
- EffA smooth muscle contraction increases hydrostatic pressure within the glomerulus
- Low pressure/flow: AII–> EffA constriction –> preserve GFR
- High pressure/flow: local synthesis of prostaglandins –> EffA vasodilation –> preserve blood flow to medulla
31
Q
Renal interstitium
- General
- Cortex
- Medulla
- Type I
- Type II
- Type III
A
- General
- Minor component of connective tissue cells b/n tubular & vascular elements of the kidney
- Cortex
- Fibroblast-like interstitial cells
- Secrete ECM & contain contractile filaments
- May secrete erythropoietin
- Phagocytic interstitial cells
- Derived from monocytes
- Fibroblast-like interstitial cells
- Medulla
- Type I interstitial cells
- Fbroblast-like w/ lipid droplets, SER, & mitochondria w/ vesicular cristae
- Site of prostaglandin synthesis to maintain blood flow in the medulla
- Type II interstitial cells
- Rounded cells w/ free ribosomes & lysosomes but no lipid droplets
- Type III interstitial cells
- Similar to pericytes, found in the BM of the vasa recta
- Source of regenerative cells to support the wall when secreting new endothelial cells
- Type I interstitial cells
33
Q
Renal circulation pathway
A
- Renal artery
- Interlobar artery
- Located b/n renal lobes
- Branch from renal arteries at the base of the medullary pyramids
- Penetrate the medulla b/n renal lobes
- Arcuate arteries
- Flow along the junction b/n cortex & medulla
- Don’t anastomose (each is responsible for supplying a specific portion of cortex)
- Interlobular arteries
- Located b/n lobules
- Arise from the arcuate & penetrate the cortex b/n medullary rays
- Give rise to AffAs directly or to short intralobular arteries first
- Intralobular arteries (sometimes)
- Afferent arterioles
- Come off intralobulra arteries & go to glomeruli
- Glomerular capillaries (capillary tufts)
- Superficial glomeruli –> peritubular capillary plexus to assimilate reabsorbed materials
- Juxtamedullary glomeruli –> vasa recta –> medulla to accompany LOH to the papillary tips
- Efferent arterioles
- 2nd capillary bed
- Follows its nephron of origin
- Superficial nephron –> short LOH –> peritubular capillaries
- Juxtamedullary nephron –> long LOH –> vasa recta
- Arcuate veins
- Interlobar veins (sometimes)
- Renal vein
- Exits renal pelvis
34
Q
Summary
- Bowman’s capsule
- Proximal tubule
- LOH
- Distal convoluted tubule
- Collecting duct
- Internal regulation/feedback
A
- Bowman’s capsule
- Glomerular capillaries
- Proximal tubule
- Peritubular capillaries b/n proximal tubules
- LOH
- Vasa recta
- Distal convoluted tubule
- Peritubular capillaries
- Collecting duct
- Vasa recta in the inner medulla
- Internal regulation/feedback
- Afferent arteriole
- Macula densa
