Download Free Medical STRUCTURE OF THE KIDNEY PowerPoint Presentation

STRUCTURE OF THE KIDNEY PowerPoint Presentation

DOWNLOAD MEDICAL POWERPOINT PRESENTATION

About This Presentation

Description : anatomy,STRUCTURE OF THE KIDNEY

Tags : STRUCTURE OF THE KIDNEY,KIDNEY

Published on : Aug 05, 2021 | Views : 1991 | Downloads : 15

Shareable Url :

Embed Code :

Comment

Transcript

Slide 1-

STRUCTURE OF THE KIDNEY DR SANTOSH SUBEDI RESIDENT DM NEPHROLOGY 2020
Slide 2-

TOPICS FOR DISCUSSION GROSS ANATOMY CUT SECTION MICROSCOPY/HISTOLOGY REFERENCES
Slide 3-

KIDNEYS Paired Bean-shaped, in retroperitoneal space, either side of spine. Each weighs about 125 to 170 gram Upper pole : T12 and Lower pole : L3 Right kidney is slightly lower than left Size : 11-12 cm x 5-7.5 cm x 2.5-3 cm Hilum : slit, renal artery and vein, renal pelvis, nerves, lymphatics Capsule : Thin, tough, fibrous tissue surrounding each kidneys.
Slide 4-

Blood supply Kidneys receive around 20 % Cardiac Output. A pair of renal artery and their tributaries Branch of abdominal aorta at level L1/L2 Supplies the kidney as well as carries blood for filtration After entering through hilum it divides in to anterior and posterior division Anterior to posterior : VEIN, ARTERY, PELVIS.
Slide 5-

SEGMENTS
Slide 6-

ppt slide no 6 content not found
Slide 7-

INTERLOBULAR INTERLOBULAR
Slide 8-

Cut surface OUTER PALE : CORTEX INNER DARK : MEDULLA 8 to 18 : Pyramids : Base : CMJ : Apex : PAPILLA EACH PAPILAE HAS 10 -25 OPENING OF THE COLLECTING DUCT : DUCTS OF BELLINI
Slide 9-

ppt slide no 9 content not found
Slide 10-

Renal lobus : pyramid with associated cortex.
Slide 11-

Renal lobe : Pyramid with associated with cortex Renal lobule : Collection of nephrons draining to common collecting duct Functional unit
Slide 12-

Pelvocalyceal system Collecting system Lined by transitional epithelium 2-3 major calyces Many minor calyces : extend to papillae : drain urine. Ureters : pelvis to fundus of bladder : 28 to 35 cm
Slide 13-

Kidney : histology 1. Nephrons 3. Collecting ducts 4. Microvasculature 2. Supporting cells Interstitium
Slide 14-

NEPHRONS The functional unit of the kidney Approximately 1 million nephrons in each kidney The number of nephron is already established during prenatal period After birth, new nephrons cannot be developed, and a lost nephron cannot be replaced
Slide 15-

Types of Nephron
Slide 16-

Parts of nephron Each nephron consists of Renal corpuscle /Glomerulus Long tubule segmented into Proximal tubule Loop of Henle Distal tubule
Slide 17-

Renal corpuscle/glomerulus Glomerular Capillaries lined by endothelium GBM Podocytes and foot process. Mesangium : supporting cells Bowman’s capsule : a pouch to capture and direct the filtrate to PCT
Slide 18-

Endothelium Highly fenestrated round to oval pores : 50 to 100 nm Luminal membrane is negatively charged due to presence of several polyanionic glycoproteins, including podocalyxin.
Slide 19-

Glomerular Basement Membrane Skeleton of the glomerular tuft. The outer aspect is covered with podocytes. The inner aspect filled with the capillary endothelium and mesangium The major components of the GBM include Type IV collagen, Laminin 11, Heparan sulfate proteoglycans (-VE charge) Type IV collagen is the antigenic target in Goodpasture’s disease Mutations in the genes of type IV collagen : Alport’s syndrome
Slide 20-

Glomerular Filtration Barrier Urine formation begins at the glomerular filtration barrier The ultrafiltrate has to pass three layers: the fenestrated endothelium the intervening glomerular basement membrane. Podocyte with slit diaphragm
Slide 21-

Podocytes Have large cell body and extensive array of foot processes Foot processes interdigitate with slit diaphragm The luminal membrane : Thick surface coat rich in sialoglycoproteins ( podocalyxin/podoendin) Responsible for the high negative surface charge The abluminal membrane : Two transmembrane proteins : α3β1 integrin, β-α- dystroglycans Connect the cytoskeleton to GBM.
Slide 22-

PODOCIN & NEPHRIN Constituent protein of slit pore diaphragm Inactivating mutation leads to severe proteiuria
Slide 23-

Mesangium Mesangial cells and mesangial matrix Mesangial cells: Irregular, many processes extending to GBM Dense assembly of microfilament : actin, myosin and alfa actinin Mesangial Matrix : Fills irregular spaces between mesangial cells & perimesangial GBM Contains collagen, microfibrillar proteins, glycopprotein and proteoglycans
Slide 24-

THE TUBULE Single-layer flat/cuboidal epithelium anchored to a basement membrane Parts
Slide 25-

The proximal tubule The PCT has prominent brush border, and extensive interdigitated basolateral infoldings. Approximately 14 mm long, diameter 40 uM Large prominent mitochondria Subdivided into three segments S1 & S2 : PARS CONVOLUTA S3 : PARS RECTA
Slide 26-

ppt slide no 26 content not found
Slide 27-

Loop Of Henle Comprises of Terminal Straight Portion PCT : water permeable Thin Ascending Limb : water impermeable : osmotic medullary gradient Thick Ascending Limb : Diluting segment Na K 2Cl cotransporter : acted upon by loop diuretics Tamm Horsefell Protein : cast and crystal formation Macula densa
Slide 28-

Distal tubule Extensive basolateral interdigitation Abundant mitochondria Luminal micro villi. Luminal NaCl cotransporter : THIAZIDES
Slide 29-

COLLECTING DUCT SYSTEM Comprises Connecting tubule Cortical collecting duct Medullary collecting duct : outer/inner Connecting tubule : CNT cells & Intercalated cells Collecting tubule : CD (Principal) cells & Intercalated cells CNT cells are only ADH responsive CD cells are both ADH & mineralocorticoid responsive
Slide 30-

CD/Principal cells Polygonal Luminal Aquaporin 2 : ADH sensitive. Luminal Amiloride sensitive Na Channel : Aldosterone responsive. Urea Transporter UTB1 : ADH responsive urea recycle. Intercalated cells Both in CNT, CDT Type A : Luminal H+ATPase : secrete proton Type B : Basolateral H+ATPase : secrete HCO3, : reabsorb proton
Slide 31-

JUXTAGLOMERULAR APPARATUS Macula Densa Extraglomerular mesangium Terminal affrent arteriole with granular JG cells : Renin Beginning of efferent arteriole MACULA DENSA (tightly packed cells with large nucleus) Specialized cells in Thick ascending limb where the limb attaches to EGM of parent glomerulus Regulates the tone of afferent arteriole and thereby glomerular blood flow and GFR: TUBULOGLOMERULAR FEEDBACK
Slide 32-

Juxtaglomerular cells Located in the granules of terminal afferent arteriole Secrete and store RENIN
Slide 33-

RENAL INTERSTITIUM Comparatively sparse, 5 -7% of cortex, 3-30% of medulla Comprises of resident fibroblast and migrating cells from the immune system the dendritic cells The space between the cells is filled with extracellular matrix (proteoglycans, glycoproteins), fibrils, and interstitial fluid. Maintain scaffold frame for glomerulus, tubules & blood vessels.
Slide 34-

References Brenner and Rectors THE KIDNEY 9th ed Comprehensive Clinical Nephrology 4th ed Greenberg primer on Kidney Disease 5th ed.
Slide 35-

Thank you
Slide 36-

DEVELOPMENT OF KIDNEYS
Slide 37-

TOPICS INTRODUCTION STAGES OF KIDNEY DEVELOPMENT NEPHROGENESIS BRANCHING MORPHOGENESIS NEPHRON ENDOWMENT REFERENCES
Slide 38-

Kidney development : NEPHROGENESIS Begins at 28th day after fertilization Completes at 8 months of gestation.
Slide 39-

Vertebrate kidneys arises from the intermediate mesoderm of the urogenital ridge which is present along posterior wall of abdomen in developing fetus. Developmentally three pair of kidneys arise sequentially in mammalian embryo namely the pronephros, mesonephros and the metanephros .
Slide 40-

ppt slide no 40 content not found
Slide 41-

Mesoderm : paraxial/intermediate/splanchnic
Slide 42-

Urogenital ridge
Slide 43-

The pronephros and mesonephros are transient structures which are reabsorbed during early fetal life. The metanephros develops into the adult kidneys.
Slide 44-

ppt slide no 44 content not found
Slide 45-

The pronephros The nephric duct originates in the thoracic region, along with pronephric tubule at around 22 days The nephric duct with its tubule at this stage is known as PRONEPHROS It also known as the precursor to the wolffian duct/Mesonephros It is functional in larval stage of fish and amphibians.
Slide 46-

ppt slide no 46 content not found
Slide 47-

The mesonephros The mesonephros develops caudal to the pronephric tubules in the midsection of the urogenital ridge. The Ureteric bud (UB) is first visible as an outgrowth at the distal end of the wolffian duct at 4th week of gestation . The mesonephros becomes the functional excretory apparatus in lower vertebrates (adult fish and amphibians).
Slide 48-

In humans the mesonephros The mesonephros in male gives rise reproductive organs : Rete Testes, Efferent Ducts, Epididymis, Vas Deferens, Seminal Vesicle and Prostate. In female the mesonephros degenerates .
Slide 49-

ppt slide no 49 content not found
Slide 50-

The metanephros Metanephros appears at around 32 days It develops from the Ureteric bud epithelium (UB) and clusture of cells known as metanephric mesenchyme (MM) Metanephros : future the adult kidney
Slide 51-

ppt slide no 51 content not found
Slide 52-

RECIPROCAL INDUCTION BETWEEN URETETIC BUD AND METANEPHRIC MESENCHYME NEPHROGENESIS glomerulus & tubules BRANCHING MORPHOGENESIS CD, Pelvocalyceal system
Slide 53-

Reciprocate inductive interaction MM cause the UB to branch into a T-tubule which then to undergo iterative branching, giving rise to the urinary collecting system and all of the collecting ducts UB sends reciprocal signals to the MM, to condense along the surface of the bud. Following condensation, a subset of MM cells aggregates known as pretubular aggregates, undergo mesenchymal-to-epithelial conversion to become the renal vesicle and nephron
Slide 54-

Ingrowth of the epithelial ureteric bud (b) into the metanephric mesenchyme (m).
Slide 55-

Cells adjacent to invading UB are induced to undergo mesenchymal to epithelial transformation. Initially the mesenchyme aggregate to form 4-5 thick cell layers called the CAP CONDENSATE around the advancing UB. Near the interface of ampulla and its adjacent ureteric branch a clusture of cells separate to form an oval mass called the PRETUBULAR AGGREGATE.
Slide 56-

ppt slide no 56 content not found
Slide 57-

ppt slide no 57 content not found
Slide 58-

An internal cavity forms within the pretubular aggregate to form the RENAL VESICLE Multiptential precursors in renal vesicle gives rise to all epithelial cell types of nephron. Nephron segmentation into glomerular and tubular domain is initiated by the sequential formation of two clefts in the renal vesicle. Creation of lower cleft (Vascular cleft) leads formation of comma shaped body.
Slide 59-

ppt slide no 59 content not found
Slide 60-

Generation of upper cleft in in the comma shaped body lead to formation of S shaped body with 3 segments : First segment – Glomerulus Second segment – Proximal tubule Third segment - Loop of Henle and DCT.
Slide 61-

Formation of glomerulus begins as the vascular cleft broadens and as lower limb of S shaped body forms cup shaped unit. Epithelial cells lining inner wall of cup comprise visceral or podocyte layer. Cells lining the outer wall of the cup forms the parietal cell layer that lines the Bowmen’s Capsule. Glomerular capillary tuft is formed by recruitment and proliferation of angioblast and mesangial precursor cells.
Slide 62-

ppt slide no 62 content not found
Slide 63-

The visceral epithelial cells and the endothelium make up the Glomerular Basement Membrane. Podocyte layer revert to mesenchymal type phenotype, flatten and spread out to cover increased surface area of growing capillary bed. Mesangial cells populate the core of the tuft and provides structural support .
Slide 64-

Branching morphogenesis The collecting system and all collecting ducts are the product of branching morphogenesis from the Ureteric Bud. Considerable remodeling occurs in the ureteric bud in the formation of collecting duct and the process is not fully understood The branching is highly patterned earlier symmetric and asymmetric in the later stages. Leading to formation of papilla and calyx. Human kidney has 8 to 10 papillae, each draining into a minor calyx, with several minor calyces draining into a smaller number of major calyces.
Slide 65-

The number of ureteric bud branches is the major determinant of final nephron number as the UB tip induces discrete subset of metanephric mesenchyme to undergo nephrogenesis. Repetitive branching events result in formation of 15 branch generations. Nephrogenesis is completed by 32nd to 34th weeks of gestation.
Slide 66-

ppt slide no 66 content not found
Slide 67-

Nephron Endowment It is the total number of functional nephron present at birth The number of nephron reaches maximum at 34th weeks of gestation At birth, total average number of nephron is 1 million in each kidney. There is no formation of new nephrons after birth rather the number only decreases through natural ageing, disease or surgical ablation.
Slide 68-

Females have fewer nephrons than males Infants born before 32nd weeks of gestation have relative nephron deficits. Individuals at lower end of nephron endowment have increased incidence of hypertension, cardiovascular disease, diabetes and ESKD
Slide 69-

BRENNER, 1988, congenital (programmed) reduction in number of nephrons predisposes to hypertension and renal injury
Slide 70-

Surrogates of adverse intrauterine environment and low renal number
Slide 71-

REFERENCES PRIMER ON KIDNEY DISEASE 7TH ED BRENNER AND RECTORS THE KIDNEY 9TH ED OXFORD TEXTBOOK OF CLINICAL NEPHROLOGY 4TH ED
Slide 72-

ppt slide no 72 content not found
Slide 73-

Renal Malformation Congenital anomalies of kidneys and urinary tract (CAKUT) malformation of