Kidney Micro anatomy

Question 1

1. What general region of the kidney is indicated in this slide?
2. What is structure A?
3. What are the structures labeled B?
4. What are the structures labeled C?

Answer 1

1. Cortex - note the renal corpuscles (the medulla does not have them)
2. Outer Capsule
3. Glomeruli of renal corpuscles
4. Blood vessels

Question 2

1. The space labeled A is (multiple choice)
   
   • A glomerulus
   • An arcuate vessel
   • A collecting duct
   • Bowman’s capsule
   • An afferent arteriole

Answer 2

1. Arcuate Vessel
   
   • First determine what region the sldie is in - notice the medulle at the bottom but also the glomeruli. So this indicates the slide is taken from the juxtomedullary nephrons
     
     • Juxta = near, so juxtamedullary =near the medulla

Question 3

1. The region encircled in yellow (multiple choice)
   
   • Is the renal papilla region of the kidney
   • Is in the outer cortex region of the kidney
   • Is in the medular region of the kidney
   • Is part of the renal calyx
   • Is a juxtamedullary region

Answer 3

1. Juxtamedullary region

Question 4

Name the region encircled in blue

Answer 4

Medulary region

• Note the parallel lines that the cells make and abscence of glomeruli, this is characteristic of the medula

Question 5

1. For the region encircled in black, name the specific structure according to what is is a part of and the relationship it has in this unique location of the tisssue

*May be hard to see the black line but it is the structure just under “A”*

Answer 5

1. Renal corpuscle of a juxtomedullary nephron
   
   • They are important b/c they go deepest into the medullary region and are important for generating hypertonic urine (concentrated urine)

Question 6

1. The structures labeled A may be part of a ______or a _____ or a ____ (cell types)?
2. The structures labeled B form the _____ epithlium of ____
3. The structures labeled C form part of the _______

Answer 6

1. Podocytes or Capillary Endothelial Cells or Mesangial Cells
2. Parietal Epithilium of Bowman’s Capsule (podocytes are the visceral epithelium)
3. Macula Densa

Question 7

1. What is normally contained in the region labeled A?

Answer 7

• Arteriole

Question 8

1. What is normally contained in the region B? (Mult choice)

• Urine
• Lymph
• RBC
• Plasma Filtrate
• Cells that secrete renin

Answer 8

• Plasma Filtrate

Question 9

1. C is in the lumen of what structure?

• Thin loop of Henle
• Renal corpuscle
• Collecting duct
• Distal convoluted tubule
• Proximal convoluted tubule?

Answer 9

• Proximal Convoluted Tubule

Question 10

1. Name 1 specific function of cell labeled E?

Answer 10

1. Synthesize, store, secrete renin
   
   • These are Juxtoglomerular (JG) cells

Question 11

1. In proceeding from the tail of the arrow to the head, what three layers are observed, and what is unique about each of them
2. Collectively what are they named?

Answer 11

1. 1. Fenestrated endothelial cell - maintanence of the basal lamina
   2. Basal Lamina - true molecular filtration barrier
   3. Podocyte layer - maintenence of the basal lamina
2. Filtration Barrier
   
   • Important to know exactly how it functions

Question 12

1. Would you exect a net flow of liquid from A to B in this structure? Or B to A? OR neither, they’re balanced in net flow?

Answer 12

1. A to B

Question 13

1. The number 1 is in the lumen of which structure? (multiple choice)
   
   • The ureter
   • The urinary space of the renal corpuscle
   • A capillary
   • A proximal convoluted tubule
   • The bladder

Answer 13

1. A capillaru
   
   • Notice the podocytes and the fenestrated endothelium this lets you know you are looking at a capillary

Question 14

1. The tips of the arrows that are shown point to what? (multiple choice)
   
   • Microvilli
   • An endothelial cell
   • Pedicels
   • A squamous cell of the parietal epithelium of Bowman’s capsule
   • Lacis cells

Answer 14

1. Endothelial cell
   
   • Recall that the 3 layers of this membrane are called the filtration barrier (that is what label #4 - reference only))
   • Label 2 is the nucleus of an endothelial cell (reference only)
   • Label 6 is the nuceleus of a mesangial cell (reference only)

Question 15

1. What is A in the lumen of? (multiple choice)
   
   • A collecting duct
   • The vasa recta
   • An ascending thick loop of Henle
   • The thin loop of Henle
   • The proximal convoluted tubule
2. What is the main role of the epithelium of this structure?

Answer 15

1. Collecting duct
   
   • The membrane is fairly thick with columnar cells
2. Responds to ADH inserts aquapores that allows you to reclaim more water - hormonally controlled

*Note* you should recognize that we are in the medulla by the parallel nature of the structures

Question 16

1. What is B in the lumen of (multiple options)?

Answer 16

1. Could be part of an ascending/descending thick limb, or could be part of a collecting tubule
   
   • *Do not need to differentiate between these under a light microscope

Question 17

1. C is in the lumen of what? (multiple choice)
   
   • A collecting duct
   • The vasa recta
   • The thin loop of Henle
   • Bowman’s Capsule
   • The proximal convoluted tubule

Answer 17

• Vasa Recta - note the RBC’s

Question 18

What main route would a 10,000MW molecule of dextran or inulin take within this tissue? (inulin/dextrose are not reclaimed, they get excreted)

• A to B
• B to C
• C to B
• B to A
• A to C
• C to A

Answer 18

• A to B: A is a collecting duct, we would not expect this route.
• B to C: C is vasa recta, you would not expect a return to the blood
• C to B: not expect anything to go from a BV in the medullary region to go to a tubule
• B to A: YES - Goes through a tubule and ends up in the collecting duct.
• A to C: No, only reclamation of water
• C to A: Plain no.

*THIS IS LIKELY A TEST QUESTION*

Question 19

• Name the structures labeled A
• Name the structures labeled B

Answer 19

• A: Ducts of Bellini (collecting ducts)
• B: Either portions of juctomedullary nephron or vasa recta

You should recognize that we are in the renal papilla

Question 20

1. T/F: The epithlelial layer labeled A is continnuous, with modifications in structure, with the parietal layer of Bowman’s capsule
2. Name the region labeled B
3. Name the region labeled C
   
   • Part of a podocyte
   • Part of a ureter
   • Lumen of a collecting tubule
   • Lumen of a collecting duct

Answer 20

1. True - we have a continuous epithelium going all the way up to Bowman’s capsule
2. B = space w/in a Minor Calyx
3. C = lumen of collecting duct (duct of bellini)

Question 21

1. What type of epithelium is spanned by the yellow line?
2. What unique property is conferred by the tissue spanned by the green line?
   
   • What specific types of fibers are located here?

Answer 21

1. Transitional epithelium
2. Green line is the lamina propria of the transitional epithelium
   
   1. Has highly stretchy elastic fibers