• Share
  • Email
  • Embed
  • Like
  • Save
  • Private Content
Renal Histo-Pathology (I) - Normal Kidney Light Microscopy
 

Renal Histo-Pathology (I) - Normal Kidney Light Microscopy

on

  • 7,872 views

by dr Mohammed Abel Gawad (drgawad@gmail.com): Nephrology Specialist at Kidney & Urology Center - Alexandria - Egypt. website: www.nephrotube.blogspot.com

by dr Mohammed Abel Gawad (drgawad@gmail.com): Nephrology Specialist at Kidney & Urology Center - Alexandria - Egypt. website: www.nephrotube.blogspot.com

Statistics

Views

Total Views
7,872
Views on SlideShare
7,871
Embed Views
1

Actions

Likes
5
Downloads
236
Comments
1

1 Embed 1

http://www.linkedin.com 1

Accessibility

Categories

Upload Details

Uploaded via as Microsoft PowerPoint

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel

11 of 1 previous next

  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

    Renal Histo-Pathology (I) - Normal Kidney Light Microscopy Renal Histo-Pathology (I) - Normal Kidney Light Microscopy Presentation Transcript

    • RENAL HISTO-PATHOLOGY (I) m NORMAL KIDNEY LIGHT MICROSCOPY Mohammed Abdel Gawad
    • Lecture References  Text Books:2  Fundamental of Renal Pathology  Handbook of Renal Biopsy Pathology  Comprehensive Clinical Nephrology  Websites: (Links are available on www.nephrotube.blogspot.com):  Histology at SIU SOM  WebPath  Kidney pathology.com  Virtual Slide  Blue Histology  HistoWeb.  Visual Histology  Zoomified Histology  Renal Pathology Tutorial  Medical histology
    • OBJECTIVES3  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • OBJECTIVES4  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • 5 In order to understand better kidney histology we must have in mind that kidney is three-dimensional structure, non bi-dimensional as we see it at microscope
    • Gross Picture6
    • Gross Picture7
    • Gross Picture8
    • Gross Picture On the cut surface, the cortex is the pale outer 9 region, approximately 1.5 cm in thickness, which has a granular appearance because of the presence of glomeruli and convoluted tubules. the medulla, a series of pyramidal structures with apical papillae, and have a striped or striated appearance because of the parallel arrangement of the tubular structures. Cortical parenchyma extends into spaces between adjacent pyramids; this portion of the cortex is known as the columns of Bertin. medullary pyramid with surrounding cortical parenchyma, which includes both columns of Bertin as well as the subcapsular cortex, constitutes a renal lobe. A renal lobule is is a part of a renal lobe. It consists of the nephrons grouped around a single medullary ray, and draining into a single collecting duct.
    • Renal Lobe10 Medullary pyramid with surrounding cortical parenchyma, which includes both columns of Bertin as well as the subcapsular cortex, constitutes a renal lobe.
    • Renal Lobule11 • A renal lobule is a part of a renal lobe. It consists of the nephrons grouped around a single medullary ray, and draining into a single collecting duct. • Lobules are centered on medullary rays (see later)
    • OBJECTIVES12  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Specimen Sections13 Very thin sections (2-3µm or less) are much better (for the definition of glomerular pathology, especially regarding cellularity, is dependent on sections of this thickness. The ability to detect subtle pathologic abnormalities is enhanced with thinner sections). Electron microscopy is essential for demonstrating functional details like capillary fenestrations and podocyte filtration slits
    • Stains14 PAS Trichrome H&E Silver
    • Stains  Silver stain accentuates (BLACK) collagenous structures,15 e.g., in the glomerulus, the mesangial matrix, the glomerular basement membrane & tubular basement membrane.  PAS stain also accentuates (RED) matrix and basement membrane constituents.  Trichrome also accentuates (BLUE) matrix and basement membrane constituents.  In certain circumstances the trichrome stain demonstrates granular immune (not linear) deposits as bright fuchsinophilic (orange, red-orange) smooth homogeneous structures.  Congo red, elastic tissue, and other stains are employed when indicated.
    • Stains16
    • OBJECTIVES17  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Where am I ?18 Cortex or Medulla !!
    • Where am I ?19 Outer or Inner Medulla !!
    • Renal Cortex20  The cortex of the kidney is distinguished by characteristic renal corpuscles, each of which consists of a glomerulus surrounded by Bowmans capsule.  Convoluted tubules comprise the bulk of the cortex. Proximal and distal tubules cannot be readily distinguished at this magnification.  Little interstitial tissue in comparison to medulla  Dense fibrous connective tissue forms a tough capsule around the kidney.
    • Renal Cortex21
    • Renal Medulla22  Note these features of the renal medulla, in contrast with the renal cortex:  No renal corpuscles are present.  All tubules are approximately parallel
    • Renal Medulla23
    • Renal Medulla24
    • Medullary Rays  Lobules are centered on "medullary rays", bundles of25 straight tubules (collecting ducts and loops of Henle) which resemble the substance of the medulla but extend into the cortex.
    • Medullary Rays26
    • Medullary Rays27
    • Medullary Rays28
    • Medullary Rays29
    • 30 Are Medullary rays in the cortex or medulla ??
    • OBJECTIVES31  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Renal Malpighian Corpuscle32 ( connective tissue matrix) (pedicles) lacis cells or cells of Goormaghtigh
    • Renal Malpighian Corpuscle33
    • Renal Malpighian Corpuscle Test Yourself34
    • Renal Corpuscle, H&E35  Renal corpuscles, each of which consists of an outer envelope of simple squamous epithelium (Bowmans capsule) surrounding a fluid-filled space (Bowmans space) within which is suspended a glomerulus.  Individual identities as endothelial cells, podocytes, or mesangial cells are difficult to determine reliably on relatively thick-sectioned specimens such as this.
    • Renal Corpuscle, H&E36
    • Renal Corpuscle, H&E37
    • Renal Corpuscle, H&E38
    • Renal Corpuscle, thin section  This 1µm section provides higher resolution.39  Podocyte cell bodies nuclei are relatively large and euchromatic.  Mesangial cell nuclei are relatively small, irregular in shape, and heterochromatic
    • OBJECTIVES40  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Glomerular Filtration Membrane & Mesangium41 ( connective tissue matrix) (pedicles) lacis cells or cells of Goormaghtigh
    • Glomerular Filtration Membrane & Mesangium42
    • Glomerular Filtration Membrane & Mesangium43
    • Glomerular Filtration Membrane & Mesangium44 (pedicles) ( connective tissue matrix)
    • Glomerular Filtration Membrane & Mesangium45
    • Glomerular Filtration Membrane46
    • 47 In order to understand better kidney histology we must have in mind that kidney is three-dimensional structure, non bi-dimensional as we see it at microscope
    • Glomerular Filtration Membrane48
    • Glomerular Filtration Membrane49
    • Stains50  Silver stain accentuates (BLACK) collagenous structures, e.g., in the glomerulus, the mesangial matrix, the glomerular basement membrane & tubular basement membrane.  PAS stain also accentuates (RED) matrix and basement membrane constituents.  Trichrome also accentuates (BLUE) matrix and basement membrane constituents.
    • Stains for Membranes & Mesangium51  The filtration membrane is not apparent on H&E stained histological specimens but may be demonstrated with PAS, trichrome or silver stain. Electron microscopy is the best way to visualize the filtration membrane.  The mesangial matrix is not apparent on H&E stained histological specimens, but (like the filtration membrane) it may be visualized with PAS, trichrome or silver stain.  It is very important to recognize the mesangial areas to determine when there is or non mesangial cell hypercellularity: cluster of three or more nuclei per mesangial area in thin 2 to 3 micron sections away from the vascular pole.  Podocyte cell bodies nuclei are relatively large and euchromatic.  Mesangial cell nuclei are relatively small, irregular in shape, and heterochromatic
    • Renal Corpuscle, PAS Stain52
    • Renal Corpuscle, PAS Stain53
    • Renal Corpuscle, PAS Stain54
    • Renal Corpuscle, PAS Stain55
    • Renal Corpuscle, PAS Stain56
    • Renal Corpuscle, Silver Stain57
    • Renal Corpuscle, Silver Stain58 GBM is thin and smooth (green arrows). The blue arrows indicate nuclei of podocytes, the cytoplasm is flat and it does not allow to delimit itself clearly with the optical microscopy. The red arrows mark some mesangial areas and nuclei of mesangial cells
    • Renal Corpuscle, Silver Stain59 The GBM is seen perfectly smooth, without perpendicular irregularities nor projections (red arrows). The flat cytoplasm of the visceral epithelial cell can be seen; and in some points, it is possible also to see the cytoplasm of the endothelial cells. The nucleus of a podocyte appears pointed with the green arrow. The nuclei of the endothelial cells usually are found towards the mesangial portion of the capillary (blue arrow)
    • Renal Corpuscle, Silver Stain60
    • Renal Corpuscle, Silver Stain61
    • Renal Corpuscle, Trichrome Stain62
    • Renal Corpuscle, Trichrome Stain63 the red arrows indicate several mesangial areas in which there are 1 or 2 nuclei. The green arrows indicate nuclei of endothelial cells
    • Renal Corpuscle, Trichrome Stain64 In this image the capillary walls, the podocytes (green arrows), nuclei of endothelial cells (blue arrows), mesangial cells (yellow arrows), and parietal epithelial cells (red arrows) are well evidenced
    • OBJECTIVES65  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Renal Tubules, PCT vs DCT66
    • Renal Tubules, PCT vs DCT67 PCT DCT simple cuboidal epithelium PCTs have nuclei spaced some what DCTs have nuclei less spaced than farther apart than those of DCTs those of PCTs more intensely eosinophilic than those less intensely eosinophilic than those comprising distal tubules comprising proximal tubules brush border of microvilli not have a brush border, although (apical ends less distinct than those of there may be scattered microvilli DCT). (apical ends more distinct than those of PCT). may be occluded lumen clearer lumen Cells are extensively interdigitated → boundaries between adjacent cells are inconspicuous (i.e., in section the epithelium looks like a continuous band of cytoplasm with nuclei appearing at irregular intervals). Because the proximal convoluted tubule is considerably longer than the distal convoluted tubule, a typical section of the renal cortex includes many more profiles of proximal tubules than of distal tubules
    • Renal Tubules, PCT68  More  Darker  More villi, less Nuclei
    • Renal Tubules, PCT vs DCT (Silver)69
    • Renal Tubules, PCT vs DCT (PAS)70 Brush border of the proximal tubules has affinity by the reagents used in the periodic acid of Schiff coloration (arrows). DCT (asterisks)
    • Renal Tubules, PCT vs DCT (PAS)71 Brush border of the proximal tubules has affinity by the reagents used in the periodic acid of Schiff coloration (arrows). DCT (asterisks)
    • Renal Tubules, PCT, H&E72
    • Renal Tubules, PCT, H&E73 abundant, eosinophilic cytoplasm and a brush border easy to identify. The cytoplasmic size, the tall cells and the brush border (arrows) are more prominent in the proximal convoluted portion
    • Renal Tubules, PCT vs DCT (H&E)74 The tall cells of the S1 segment are seen almost occluding the tubular lumen in many of the histologic sections. This microphotography shows this portion of proximal tubule (from upper left corner to bottom right corner) surrounded by distal tubules
    • Renal Tubules, PCT vs DCT (H&E)75
    • Renal Tubules, PCT vs DCT (H&E)76
    • Renal Tubules, PCT vs DCT (H&E)77
    • Renal Tubules, PCT, Trichrome78 In the proximal tubules is not unusual to find its cytoplasm occupied by droplets of protein resorption, they are shown here like small green spheres in a tubule.
    • OBJECTIVES79  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Juxtaglomerular Apparatus80
    • Juxtaglomerular Apparatus81 ( connective tissue matrix) (pedicles) lacis cells or cells of Goormaghtigh
    • Juxtaglomerular Apparatus82
    • 83 Juxtaglomerular Apparatus, Vascular Pole, H&E
    • 84 Juxtaglomerular Apparatus, Vascular Pole, H&E
    • 85 Juxtaglomerular Apparatus, Vascular Pole, H&E •The yellow arrows indicate the macula densa, see the apical nuclei. •Almost in contact with macula densa cells is the extraglomerular mesangium with the Lacis or Goormaghtigh cells, indicated with the black arrows. •The green arrow marks the efferent arteriole and the blue arrow the afferent arteriole. •The Peripolar cells (cells located just at the transition of the parietal to the visceral epithelium) are located exactly in the angle in which parietal epithelium contacts visceral epithelium
    • 86 Juxtaglomerular Apparatus, Vascular Pole, Trichrome Other image of the juxtaglomerular apparatus let us see the Lacis cells (black arrows), the macula densa (yellow arrows), and two nuclei of peripolar cells, in both angles of the vascular pole.
    • Macula Densa, Vascular Pole87  The macula densa may be seen at the vascular pole of the corpuscle, displaying its characteristic appearance of several distal tubule nuclei crowded densely together.
    • Afferent Arteriole, Vascular Pole88
    • Afferent Arteriole, Vascular Pole89
    • Afferent Arteriole, Vascular Pole90
    • Afferent Arteriole, Vascular Pole91
    • Macula Densa, Afferent Arteriole92 Conspicuous left of center is the macula densa of a distal tubule, presumably close to a renal corpuscle that is not visible in this plane of section. Beside the macula densa is a small afferent arteriole, probably originating from the interlobular artery at lower left and presumably leading to the glomerulus that is associated with this juxtaglomerular apparatus.
    • Macula Densa, Afferent Arteriole93 Conspicuous left of center is the macula densa of a distal tubule, presumably close to a renal corpuscle that is not visible in this plane of section. Beside the macula densa is a small afferent arteriole, probably originating from the interlobular artery at lower left and presumably leading to the glomerulus that is associated with this juxtaglomerular apparatus. At the left side of the image is another small arteriole, probably afferent to another corpuscle, cut in longitudinal section.
    • Juxtaglomerular Cells, Vascular Pole94  This image from a thin (1µm) section shows sufficient detail to resolve secretory granules within juxtaglomerular cells, found in the wall of an afferent arteriole.
    • OBJECTIVES95  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Renal Tubules, Loop of Henle & Collecting Ducts96
    • Where am I ?97 Cortex or Medulla !!
    • Where am I ?98 Outer or Inner Medulla !!
    • Where am I ?99 Outer or Inner Medulla !!
    • Renal Medulla100  Note these features of the renal medulla, in contrast with the renal cortex:  No renal corpuscles are present.  All tubules are approximately parallel
    • Renal Medulla101
    • Renal Medulla102
    • Renal Medulla,Loop of Henle vs Collecting Duct (H&E)  thin segment of the loop of Henle:103  lined by squamous epithelial cells.  thick segment of the loop of Henle (same as DCT):  lined by cuboidal epithelial cells.  having eosinophilic cytoplasm.  no apparent cell boundaries.  collecting duct: (less specialized than PCT & DCT):  lined by cuboidal epithelial cells.  having relatively clear cytoplasm.  distinct cell boundaries.
    • Renal Medulla,Loop of Henle vs Collecting Duct (H&E)104
    • Renal Medulla,Loop of Henle vs Collecting Duct (H&E)105
    • Renal Medulla,Loop of Henle vs Collecting Duct (H&E)106
    • Renal Medulla,Loop of Henle vs Collecting Duct (H&E)107
    • Renal Medulla, Vessels vs Thin Loop of Henle (H&E)108 In this image we can see distal tubules at both sides of a thin portion of the thin limb of Henle with a hyaline cast (arrow). In many cases it is very difficult, with light microscopy, to differentiate if small spaces in the medulla, like this here observed, are peritubular capillaries or thin portion of the limb of Henle.
    • Renal Medulla, Vessels vs Thin Loop of Henle (H&E)109 Because both are lined by simple squamous epithelium, vessels and loops can be difficult to distinguish. Epithelial cells lining loops are often conspicuously rounded in the vicinity of the nucleus, not as flat as vascular endothelium. Medullary blood vessels may sometimes be distinguished by the presence red blood cells as well as by a an endothelial lining which may be lower (flatter) than the tubular epithelium.
    • Renal Medulla, Loop of Henle (H&E)110  Note that epithelial cells lining thin segment are distinctly thinner than epithelial cells lining thick segments of loops of Henle.
    • Renal Medulla,Loop of Henle vs Collecting Duct (H&E)111  Note that epithelial cells lining collecting ducts have more distinct cell boundaries and clearer cytoplasm than epithelial cells lining thick segments of loops of Henle.
    • Renal Medulla, Collecting Ducts (H&E)112  This image shows two collecting ducts merging into a larger duct, deep in the medulla.  The surrounding tissue consists of medullary blood vessels and thin segments of loops of Henle. (Because both are lined by simple squamous epithelium, vessels and loops can be difficult to distinguish, except when blood is present in the vessels).
    • Renal Medulla, Collecting Ducts (H&E)113
    • Renal Medulla, Collecting Ducts (H&E)114
    • DCT vs Collecting Duct (H&E)115 Where am I ? Cortex or Medulla !!  Distal tubule and collecting duct cells have less eosinophilic cytoplasm than proximal tubule cells. See a clear halo surrounding the nucleus in many cells.
    • DCT vs Collecting Duct (H&E)116 Where am I ? Cortex or Medulla !!  In this image we see collecting duct cells. Distal tubule cells gradually change to collecting duct cells and the histologic aspect, in many cases, do not permit differentiate between cells of this portions of the nephron with light microscopy.
    • DCT vs Collecting Duct (Silver)117 Where am I ? Cortex or Medulla !!
    • Renal Medulla – Which level ?118 Outer or Inner Medulla ?  Note these features of the renal medulla, in contrast with the renal cortex:  No renal corpuscles are present.  All tubules are approximately parallel
    • Renal Medulla – Which level ?119 Outer or Inner Medulla ? •The larger tubules in this image are collecting ducts. •The smaller tubules are ascending thick segments of loops of Henle. •Descending thin segments are present but not conspicuous at this magnification.
    • Renal Medulla – Which level ?120 Outer or Inner Medulla ?  This image shows collecting ducts deep in the medulla.  The surrounding tissue consists of medullary blood vessels and thin segments of loops of Henle. (Because both are lined by simple squamous epithelium, vessels and loops can be difficult to distinguish, except when blood is present in the vessels).
    • Renal Medulla Ducts of Bellini121
    • Renal Pelvis122  The transitional epithelium of the renal pelvis is continuous with that of the ureters and bladder
    • OBJECTIVES123  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • Renal vasculature124
    • Renal Vasculature, Angiogram125
    • Renal Vasculature, Vascular dye injection126
    • Renal Vasculature, Vascular dye injection127
    • Renal Vasculature, Vascular dye injection128
    • 129  The renal arteries and arterioles have the same histologic structure that arteries or arterioles elsewhere in the body. They are formed by endothelium, subendothelial connective tissue or intima, internal elastic lamella (difficult to identify in the small arteries), muscular media, and adventitia that fuses with the interstitial tissue.
    • Arcuate Artery (H&E)130
    • Interlobular Arteriole (PAS)131  Low magnification of cortex with portions of two glomeruli, tubules, and interstitium and interlobular artery with arteriolar branch
    • Interlobular Arteriole (Silver)132  Low magnification of cortex. An arcuate artery (AA), interlobular artery (IA), and afferent arteriole (aa) are in continuity
    • Interlobular Arteriole (Trichrome)133  Interlobular artery (IA) with afferent arteriole (aa) extending into glomerulus
    • Interlobular Arteriole (H&E)134
    • Interlobular Arteriole (H&E)135
    • Renal Medulla, Vasa Recta (H&E)136  Vasa recta appear as tightly packed bundles of vessels.  In this specimen, most tubules are cut lengthwise, indicating that the plane of section is perpendicular to the cortex.
    • Renal Medulla, Vasa Recta (H&E)137  Vasa recta appear as tightly packed bundles of vessels.  In this specimen, most tubules are cut lengthwise, indicating that the plane of section is perpendicular to the cortex.
    • Renal Medulla, Vessels vs Thin Loop of Henle138 Because both are lined by simple squamous epithelium, vessels and loops can be difficult to distinguish. pithelial cells lining loops are often conspicuously rounded in the vicinity of the nucleus, not as flat as vascular endothelium. Medullary blood vessels may sometimes be distinguished by the presence red blood cells as well as by a an endothelial lining which may be lower (flatter) than the tubular epithelium.
    • OBJECTIVES139  Gross Picture  Specimen Sectioning & Stains  Where am I ?  Renal Malipighian Corpuscle (Bowman’s space)  Renal Malipighian Corpuscle (GBM & Mesangium)  Renal Tubules (PCT vs DCT)  Juxtaglomerular Apparatus  Renal Tubules (Loop of Henle & Collecting Ducts)  Renal Vasculature  Self Assessment Quiz
    • 140
    • 141
    • 142  Papilla (right) projecting into calyx (left) lined with transitional epithelium.
    • 143
    • 144 Cortex of kidney: alternating straight medullary rays and convoluted portions (with glomeruli). One longitudinally cut interlobular artery (pale pink contents) can be seen near the extreme left border of the picture, running up the middle of a convoluted portion, among glomeruli.
    • 145
    • 146  Renal corpuscle with connection to proximal tubule at lower border. This, then, would be a cut through the urinary pole of the corpuscle.
    • 147
    • 148  Detail of renal corpuscle. Dark pink epithelium = proximal tubule. Lighter pink (as at upper top left) = distal tubule.
    • 149
    • 150  Dark pink = proximal tubule. Lighter, low cuboidal epithelium (as at top left) = distal tubule.
    • 151
    • 152  Thin segment of Loop of Henle (in the middle), with a simple squamous lining. Collecting ducts are present.
    • 153
    • 154
    • 155  Medullary region. There are some longitudinal cuts of pale collecting tubules (at left center) and several blood vessels filled with pale pink fluid (to the right). Epithelium of collecting tubules is regular, block-like, simple cuboidal, with unusually clear cell walls. Other tubules in the field are thick and thin limbs of loops of Henle
    • 156
    • 157
    • 158  Cross cuts in medulla. Collecting tubules. Simple squamous lining indicates thin loops of Henle. Compare these with blood vessels, which contain r.b.c.s. (Look for vessels up near top center and to right; also in lower left quadrant of field).
    • 159
    • 160  Large pale tubules are collecting tubules, with clear epithelial cell boundaries. Brighter pink tubules are thick portions of loops of Henle; these are basically like distal convoluted tubules in their histology, so would be ascending limbs.
    • 161
    • 162  Renal corpuscle in trichome stain to show bright orange r.b.c.s in both the glomerular capillaries and the peritubular capillaries (among the convoluted tubules). Notice also the clear simple squamous epithelium of the parietal layer of Bowmans capsule outlining the whole renal corpuscle.
    • 163
    • 164  Long thin artery leading to glomerulus (look in lower mid-picture). (Note long, thin endothelial nuclei lining the lumen. Circular muscle fibers have been cross-cut and look almost like a simple cuboidal epithelium outside the endothelium.)
    • 165
    • 166  Detail of wall of renal corpuscle. The space is the lumen of Bowmans capsule that receives glomerular filtrate from the capillary loops. Left wall is simple squamous parietal lining. The visceral lining of podocytes on the right wall of the space is too irregular to be seen clearly in light microscopy because it is following the curves of the individual capillaries.
    • 167
    • 168  At lower right pole of glomerulus, note a triangular wedge of Polkissen cells (JG cells) just to the left of the straight row of macula densa cells. The latter are part of the epithelial wall of the distal tubule.
    • 169
    • 170  This one shows the vascular pole of a renal corpuscle. The blood vessel is presumably an efferent arteriole because no "cuboidal" J-G cells are seen in its wall. (Note the biconcave shape of the rbcs in the vessel.) Notice also the clear parietal layer of Bowmans capsule. Surrounding the renal corpuscle are several cuts of the proximal tubule, with clear brush borders. There is one small distal tubule at bottom center of the field, slightly to the left.
    • 171
    • 172  This renal corpuscle has been sectioned through the urinary pole where the proximal tubule is continuous with the urinary space containing the urinary filtrate.
    • 173
    • 174
    • 175  A field of convoluted tubules, some with striated (brush) borders and some without. Notice also the small peritubular lying between the proximal and distal tubules
    • 176
    • 177  glomerulus, juxtaglomerular apparatus (macula densa)
    • 178
    • 179  proximal tubule, distal tubule
    • 180
    • 181  distal tubule and collecting duct
    • 182
    • 183  Thick & Thin Limbs Loop of Henle
    • 184 Follow On www.nephrotube.blogspot.com & Facebook Group NephroTube
    • 185 Gawad