Objectives of the BlockBy the end of the course, students should be able to:• Understand the relationship between the structure of the

different components of the renal system and their functions.

• Discuss the biochemistry, pathology, microbiology, pathogenesis and factors contributing to the development of

most common diseases affecting renal system.• Use basic science to explain patient’s sign and symptoms;

– interpret investigation results, and

– provide justification for their views.

• Develop communication skills and explore psychosocial and ethical issues in their assessment.

• Use clinical cases to apply knowledge learnt, generate hypotheses, build an enquiry plan, and use evidence to refine their hypothesis, justify their views.

• Design a brief management plan, and understand the pharmacological basis of drugs used in the management of common diseases affecting the renal system.

• Enhance their communication skills, and practice with the help of simulation patients to improve their communication in relation to renal case scenarios.

Teaching and Learning Modes:

Learning strategies include: Small group discussion Lectures Student-led seminars Practical classes. Clinical skills Independent learning Writing an essay or mini thesis.

Assessment of Studentsin the Block

In order to pass the block, you must obtain a minimum final block grade of D calculated as:

• Continuous Assessment – Tutor Assessment and Attendance 15%

• Written Examinations (MCQ) 55%

– Mid-Block Exam 25%

– Final Block Exam 30%

• OSPE 30 %

• TOTAL : 100 %

• Attendance

– 75% attendance in all educational activities of the block.

• Tutor Assessment in Large and Small groups (Continuous Assessment):

– Preparation

– Participation

• Written Examination

– Mid-block Exam

– Final Written Exam

• Objective Structured Practical Examination (OSPE ):

– Practical examination at the end of the block

– Contains 30% of the marks

Learning Resources

• Please see Renal Block guide.

Anatomy of The Anatomy of The KidneyKidney

By the end of the lecture, the student should be able By the end of the lecture, the student should be able to describe the:to describe the:

Anatomical features of the kidneys: position, Anatomical features of the kidneys: position, extent, relations, hilum, peritoneal coveringsextent, relations, hilum, peritoneal coverings

Internal structure of the kidneys: Cortex, medulla Internal structure of the kidneys: Cortex, medulla and renal sinusand renal sinus

The vascular segments of the kidneysThe vascular segments of the kidneys The blood supply and lymphatics of the kidneys.The blood supply and lymphatics of the kidneys.

ObjectivesObjectives

• The The kidneys kidneys are are retroperitoneal retroperitoneal paired organspaired organs

• Each kidney lies Each kidney lies lateral to the lateral to the vertebral columnvertebral column, , on the posterior on the posterior abdominal abdominal wall largely wall largely under cover under cover of the costal marginof the costal margin

• In the supine position, the kidneys In the supine position, the kidneys extend from approximately extend from approximately T12 T12 vertebra superiorly to L3 vertebra vertebra superiorly to L3 vertebra inferiorlyinferiorly

• The The right kidney lies slightly lower right kidney lies slightly lower than the left kidney than the left kidney because of the because of the large size of the right lobe of the large size of the right lobe of the liver.liver.

• With contraction of the diaphragm With contraction of the diaphragm during respiration, both kidneys during respiration, both kidneys move downward in a vertical move downward in a vertical direction by as much as 1 in. (2.5 cm)direction by as much as 1 in. (2.5 cm)

Location & Position of the kidneysLocation & Position of the kidneys

• The Kidneys are reddish brown bean-The Kidneys are reddish brown bean-shaped organs with the dimensions of shaped organs with the dimensions of 12 x 6 x 3cm12 x 6 x 3cm

• Although they are similar in size and Although they are similar in size and shape, the shape, the left kidney is a longer and left kidney is a longer and more slender more slender organ than the right organ than the right kidney, and kidney, and nearer to the midlinenearer to the midline..

• Each kidneys has:Each kidneys has: Convex upper & lower endsConvex upper & lower ends A convex lateral borderA convex lateral border A medial border that has a vertical A medial border that has a vertical

slit called the slit called the hilumhilum• Internally the hilum extends into a Internally the hilum extends into a

large cavity called the large cavity called the renal sinus. renal sinus.

Color, Shape & Dimensions of the kidneysColor, Shape & Dimensions of the kidneys

• The hilum transmits, from The hilum transmits, from the front backward, the the front backward, the renal vein, renal artery & renal vein, renal artery & the ureter (the ureter (VAUVAU) )

• Lymph vessels and Lymph vessels and sympathetic fibers also sympathetic fibers also pass through the hilum.pass through the hilum.

• The renal sinus contains The renal sinus contains the upper expanded part the upper expanded part of the ureter called the of the ureter called the Renal pelvisRenal pelvis

• Perirenal fat continues into Perirenal fat continues into the hilum and sinus and the hilum and sinus and surrounds all structures.surrounds all structures.

Renal Hilum & Renal sinusRenal Hilum & Renal sinus

1.1. Fibrous capsule: Fibrous capsule: Surrounds the Surrounds the kidney and is closely applied to the kidney and is closely applied to the outer surface.outer surface.

2.2. Perirenal fatPerirenal fat: Covers the fibrous : Covers the fibrous capsulecapsule

3.3. Renal (Perirenal) fasciaRenal (Perirenal) fascia: : Condensation of connective tissue Condensation of connective tissue that lies outside the perirenal fat that lies outside the perirenal fat and encloses the kidney and the and encloses the kidney and the suprarenal glandsuprarenal gland

4.4. Pararenal fatPararenal fat: Lies external to the : Lies external to the renal fascia, is part of the renal fascia, is part of the retroperitoneal fat retroperitoneal fat

Structures 2,3 & 4 support the Structures 2,3 & 4 support the kidneys and hold them in position kidneys and hold them in position on the posterior abdominal wall. on the posterior abdominal wall.

CoveringsCoverings

RelationsRelations

The The anterior surface anterior surface of of the both kidneys are the both kidneys are related to numerous related to numerous structures, that are structures, that are different on both sides. different on both sides. some of these structures some of these structures have an have an intervening layer intervening layer of peritoneumof peritoneum and some and some lie lie directlydirectly against the against the surface of the kidneysurface of the kidney.

The The posterior surface posterior surface of the right and left kidneys are of the right and left kidneys are related to similar structures. related to similar structures.

Left kidneyLeft kidney• a small part of the a small part of the superior polesuperior pole, on , on

its medial side, is covered by the its medial side, is covered by the left left suprarenal glandsuprarenal gland

• the rest of the superior pole is the rest of the superior pole is covered by the covered by the stomach and spleen stomach and spleen

• moving inferiorly, the moving inferiorly, the retroperitoneal pancreas retroperitoneal pancreas covers the covers the middle part of the kidney; middle part of the kidney;

• on its lateral side, the lower half of on its lateral side, the lower half of the kidney is covered by the the kidney is covered by the left left colic flexure colic flexure and the beginning of and the beginning of the descending colon, and,the descending colon, and,

• on its medial side, by the parts of on its medial side, by the parts of the the small intestine. small intestine.

Relations:Relations: AnteriorAnterior

Note that peritoneum intervenes between the kidney and the

stomach, spleen and small intestine.

Right kidneyRight kidney• a small part of the a small part of the superior polesuperior pole is is

covered by the covered by the right suprarenal right suprarenal gland gland

• moving inferiorly, a large part of the moving inferiorly, a large part of the rest of the upper part of the rest of the upper part of the anterior surfaceanterior surface is against the is against the liverliver

• medially, the medially, the descending part of descending part of the duodenum the duodenum is retroperitoneal is retroperitoneal and contacts the kidney; and contacts the kidney;

• the the inferior poleinferior pole of the kidney, on of the kidney, on its lateral side, is directly associated its lateral side, is directly associated with the with the right colic flexure right colic flexure and, on and, on its medial side, is covered by a its medial side, is covered by a segment of the segment of the small intestine. small intestine.

Relations: AnteriorRelations: Anterior

Note that peritoneum intervenes between the kidney and the liver

and small intestine

• As the left kidney lies at higher As the left kidney lies at higher level than the right, it is related level than the right, it is related to to 1111thth & 12th ribs & 12th ribs and the and the last last intercostal space.intercostal space.The right The right kidney is related to kidney is related to 1212thth rib rib and and the the last intercostal space.last intercostal space.

• The diaphragm & the The diaphragm & the costodiaphragmatic recess costodiaphragmatic recess intervene between the thoracic intervene between the thoracic wall & the kidneywall & the kidney

• Psoas, quadratus lumborum, Psoas, quadratus lumborum, transversus abdominis muscles transversus abdominis muscles (from medial to lateral)(from medial to lateral)

• Subcostal (T12), ilio-hypogastric Subcostal (T12), ilio-hypogastric & ilio-inguinal nerves & ilio-inguinal nerves

Relations:Relations: PosteriorPosterior

Vertebrocostal & Renal AnglesVertebrocostal & Renal Angles

• Renal angleRenal angle: : The angle The angle between the between the last rib last rib and the and the lateral border of lateral border of erector erector spinae muscle, spinae muscle, is occupied is occupied by kidneyby kidney

• Vertebrocostal angleVertebrocostal angle:: The The angle between the angle between the last riblast rib and the lateral border of and the lateral border of vertebral column , is vertebral column , is occupied by lower part of occupied by lower part of the pleural sac.the pleural sac.

Erector spinae

Renal angleVertebrocostal angle

• Each kidney consists of an outer Each kidney consists of an outer renal cortexrenal cortex and an inner and an inner renal renal medulla. medulla.

• The renal cortex is a continuous The renal cortex is a continuous band of pale tissue that band of pale tissue that completely surrounds the renal completely surrounds the renal medulla. medulla.

• Extensions of the renal cortex, Extensions of the renal cortex, the the renal columnsrenal columns project into project into the inner aspect of the kidney, the inner aspect of the kidney, dividing the renal medulla into dividing the renal medulla into discontinuous aggregations of discontinuous aggregations of triangular-shaped tissue, the triangular-shaped tissue, the renal pyramidsrenal pyramids..

Internal structureInternal structure

• The The basesbases of the renal of the renal pyramids are directed pyramids are directed outward, toward the renal outward, toward the renal cortex, while the cortex, while the apex apex (called (called the the Renal papilla) Renal papilla) of each renal of each renal pyramid projects inward, pyramid projects inward, toward the toward the renal sinusrenal sinus. .

• The The renal papillarenal papilla is surrounded is surrounded by a cup shaped by a cup shaped minor calyx minor calyx

• In the renal sinus, several In the renal sinus, several minor calices unite to form a minor calices unite to form a major calyxmajor calyx, and two or three , and two or three major calices unite to form the major calices unite to form the renal pelvisrenal pelvis, which is the , which is the funnel-shaped superior end of funnel-shaped superior end of the ureters. the ureters.

Base Apex

• The The renal artery renal artery arises from the arises from the aortaaorta at the level of the at the level of the second second lumbar vertebra. lumbar vertebra.

• Each renal artery divides into Each renal artery divides into 5 5 segmental arteriessegmental arteries that enter the that enter the hilum of the kidney, 4 in front of hilum of the kidney, 4 in front of and one behind the renal pelvis. and one behind the renal pelvis. They are distributed toThey are distributed to t the he different different segments of the kidneysegments of the kidney..

• Each segmental artery gives rise to Each segmental artery gives rise to number of number of lobar arterieslobar arteries, each , each supplies a renal pyramid.supplies a renal pyramid.

• Before entering the renal Before entering the renal substance, each lobar artery gives substance, each lobar artery gives off two or three interlobar arteriesoff two or three interlobar arteries

Arterial SupplyArterial Supply

Interlobar arteries

Segmental arteries

Lobararteries

• The interlobar arteries run toward the cortex on each side of the renal pyramid.

• At the junction of the cortex and the medulla, the interlobar arteries give off the arcuate arteries, which arch over the bases of the pyramids.

• The arcuate arteries give off several interlobular arteries that ascend in the cortex and give off the afferent afferent glomerular arteriolesglomerular arterioles.

Arcuate arteries

Interlobular arteries

Interlobar arteries

• Each kidney has 5 segmental branches and thus is divided into 5 vascular segments named as:

1. Apical2. Caudal3. Anterior Superior4. Anterior Inferior5. Posterior

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Segmental branches & Segmental branches & vascular segments of vascular segments of

kidneyskidneys

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Glomerulus

Blood SupplyBlood Supply

The left renal vein: The left renal vein: • Is three times Is three times longerlonger than the right (7.5 cm and than the right (7.5 cm and

2.5 cm). 2.5 cm). So,So, for this reason the left kidney is the for this reason the left kidney is the preferred side for live donor preferred side for live donor nephrectomynephrectomy. .

• Course: Course: RunsRuns from its origin in the renal hilum:from its origin in the renal hilum:• Posterior to the splenic vein and the body Posterior to the splenic vein and the body

of pancreas, andof pancreas, and• Then across the anterior aspect of the Then across the anterior aspect of the

aorta, just below the origin of the superior aorta, just below the origin of the superior mesenteric artery. mesenteric artery.

• Tributaries:Tributaries: • Left gonadal vein enters it from belowLeft gonadal vein enters it from below• Left suprarenal vein, usually receiving one Left suprarenal vein, usually receiving one

of the left inferior phrenic veins, enters it of the left inferior phrenic veins, enters it aboveabove

Venous DrainageVenous Drainage

The right renal vein:The right renal vein:• Lies behind the 2Lies behind the 2ndnd part of part of

the duodenum and the duodenum and sometimes the lateral part of sometimes the lateral part of the head of the pancreasthe head of the pancreas

Both renal veins drain to the inferior vena cava. The left renal vein enters the inferior vena cava a little above the right vein.

Lymphatic DrainageLymphatic DrainageThe lymph vessels follow The lymph vessels follow

the arteries. Lymph drains the arteries. Lymph drains to the to the lateral aortic lateral aortic

lymph nodes lymph nodes around the around the origin of the renal artery.origin of the renal artery.

Nerve SupplyNerve SupplyThe nerve supply is the The nerve supply is the renal sympathetic plexusrenal sympathetic plexus. The afferent fibers . The afferent fibers

that travel through the renal plexus enter the spinal cord in the T10-12 that travel through the renal plexus enter the spinal cord in the T10-12 nerves.nerves.

Lymphatic Drainage & Nerve SupplyLymphatic Drainage & Nerve Supply