Histology of the Kidney Flashcards
List the sequence of arteries from the renal artery to the efferent arteriole
- Renal artery
- Interlobar arteries
- Arcuate arteries
- Interlobular arteries
- Afferent arterioles
- Efferent arterioles
**Veins have the same naming system
Describe the path of urine once it enters into the collecting duct
- Collecting duct
- (Papilla) = opening of pyramid
- Minor calyx
- Major calyx
- Renal Pelvis
- Hilum/ ureter
Which arteries run parallel to the outer capsule at the medullary-cortical junctions?
Arcuate Arteries
What is the difference between the efferent arterioles of the outer cortex vs. the efferent arterioles of the juxtamedullary region?
Outer cortex:
- E.A. form a capillary plexus (vasa recta) that initially surround the tubules then can enter into medulla as a capillary plexus
Near Medulla:
- E.A. directly enter into medulla (no vasa recta)
List the path of filtrate from the afferent arteriole to the collecting duct
- AA
- Glomerulus
- Bowman’s space
- Proximal convuluted tubules
- Thin descending limb of loop of Henle
- Thin ascending limb of loop of Henle
- Thick ascending limb of loop of Henle
- Distal convuluted tubule
- Collecting tubule
- Collecting duct
What section of the kidney is this?
Cortex
The tubules of the loop of Henle usually extend down into the medulla. How are tubules of the juxtamedullary nephrons different?
=These extend into the deepest part of the medulla
- Additional function of establishing medullary salt gradient
What is the purpose of the renal corpuscle and what is it composed of?
=Where filtration occurs
Composed of:
- glomerulus (capillary network)
- Bowman’s capsule
- Podocytes
- Mesangium (CT in interior of capillary bed)
- Basal lamina (between cap. endothelium + podocytes)
Which of the above listed components is considered the filtration barrier?
Basal lamina
- His notes contradict and also say the the fenestrated endothelium + podocyte slits/ membrane compose part of the filtration barrier
- But basal lamina is most important
- Fenestrated endoth. tries to block out RBC’s, platelets, etc. but all components of blood can come into contact with basal lamina
What are pedicells?
The “fingers” coming off of podocytes
- T/F: podocytes are the visceral epithelial layer of Bowman’s capsule?
- T/F: The parietal and visceral layer of Bowman’s capsule are a continuous squamous epithelium?
- T/F: the bowman’s space is separated from the proximal conv. tubues by the parietal epithelium?
- TRUE:
- FALSE: The two layers are continuous at the base of the glomerulus, but only the parietal is simple squamous (podocytes are different)
- FALSE: Bowman’s space is continuous with the lumen that will eventually drain into a minor calyx (see image below showing “urinary pole”- or beginning of PCT)
What’s the function of the mesangial cells?
- CT to support glomerular structure
- Secrete matrix that is continuous with basal lamina
- Phagocytic and might play a role in maintenance of lamina
- Contraction (though not clear)
Roughly 75 - 85% of filtrate is absorbed in the proximal tubule. Describe the following characteristics of these cells:
- What cell type (squamous, cuboidal, stratified..)
- What’s unique to apical side?
- What’s unique to basolateral side?
- What organelle is prevalent?
- Cuboidal
- Extensive microvilli (brush border), cells are connected near surface w/ tight junctions (4)
- infolds rich in Na/K ATPase (gradient for facilitated diffusion) (12)
- mitochondria (6)
How are the cell types/ functions different between the thin (descending/ascending) and thick portions of the loop of Henle?
Thin: Simple squamous
- Thin descending: absorb H2O (passive)
- Thn ascending: absorb Na (passive)
Thick: Cuboidal (also- active transporters of Na)
What are the cell types in the DCT, collecting tubules, the collecting duct, and the bladder?
DCT: cuboidal (similar to PCT, just shorter microvilli)
Collecting tubule: cuboidal transitioning to columnar
Collecting duct: columnar
Bladder: Transitional epithelium (unique lamina propria with elastic CT to stretch)
- SEE BELOW IMAGE
I don’t think he talked about this much, but the collecting tubule has two cells:
Principal & intercalated cells.
What is their function?
Principal: active transporters of Na uptake (Potassium regulation)
- Other cells below
Intercalated: regulate acid/ base (secrete H, reabsorb bicarb)
- Cell with asterisk below
What is the macula densa? Where is it located?
=Specialized cells of the thick ascending limb/ DCT that sense afferent arteriole Cl-
- Located in the juxtaglomerular complex
What section of the nephron is shown?
Proximal Convuluted tubule- notice the tall microvilli
What region is being shown?
How can you distinguish between collecting duct/ PCT/DVT/ loop of henle/ blood vessels?
Medullary region
- Collecting duct: large vessel seen in middle
- PCT/DCT: smaller vessels with thicker cuboidal walls
- loop of henle: see the transition from thin squamous cell walls to thick ascending limb
- blood vessels: see RBCs in them
It tells you what the cells are, but how could you tell the difference?
Ascending thick limb: mitochondria
Collecting tubule: less mitochondria but thick
Descending thin limb: thinner
Vasa recta: Very thin with fenestrations
***PROBABLY WON’T HAVE TO DISTINGUISH BUT FOR YOUR REFERENCE
What are the following cells (1, 5, 2)?
1 = thin limb of loop of Henle: squamous, no RBCs
5 = Vasa recta: blood cells
2 = thick ascending limb
