[Music] anatomy of the kidney introduction kidneys are major excretory organs which lie on posterior abdominal wall one on each side of the vertebral column behind the Peroni location kidneys extend from upper border of T12 vertebrae to center of body of L3 vertebrae right kidney is slightly lower than the left kidney due to the presence of liver upper ends or poles of two kidneys are nearer to each other than lower poles as long ax are slightly oblique being directed downward and laterally upper poles are 2.5 cm away from the midline hilum is 5 cm away from midline and lower poles are 7.5 cm away from the midline transpyloric plane passes through upper part of hilum of right kidney and through lower part ofum of left kidney shape is being shape measurements length is 11 cm width is 6 cm thickness 3 cm weight 150 g in Mees and 135 G in females external features each kidney has two poles Superior and inferior two surfaces anterior and posterior two borders medial and lateral and AUM poles Superior pole is thick round and closer to the median plane and is related to the suprarenal gland inferior pole is thin pointed lies 2.5 cm above the iliac crest coming to the surfaces anterior surface is convex and faces anterior laterally posterior surface is flat and faces posterior medially it is difficult to recognize anterior and posterior surfaces borders lateral border is convex medial border is convex above and below near the poles and concave in the middle and slopes downward and laterally with vertical fissure in the middle part known as the hilum hilum it is the medial border or the central part of the kidney with deep vertical slit it transmits the following structures from anterior to posterior renal vein renal artery renal pelvis subsidiary branch of renal artery in addition to the above hilum also transmits lymphatics and nerves sympathetic relations of kidney anterior relations anterior relations of two kidneys are different anterior relation of the right kidney are as follows right suprarenal gland right lobe of liver second part of deinum hepatic flexure of colon judum liver and judum are separated from Kid by Peroni anterior relations of left kidney left suprarenal gland spleen stomach pancreas splenic vessels splenic flexure of colon judum stomach spleen judum is separated from kidney by Peroni posterior relations posterior relations of two kidneys are the same except in relation to ribs it is different for muscles which include the diaphragm quadratus lumborum soas major and transverses abdominis three nerves sub Coastal T12 iloh hypogastric L1 ilioinguinal L1 Ribs Right kidney is related to 12th rib whereas left kidney is related to the 11th and 12th ribs capsules of kidney from inside to outwards the kidney is surrounded by four capsules or coverings fibers capsule which is the true capsule peral or perinephric fat renal fascia pararenal or paranephric fat fibbr capsule it is also known as the true capsule it is formed by condensation of fi stroma in the peripheral part of kidney it is a thin membrane which closely covers the entire kidney it then passes through the hilum and lines renal sinus and is continuous with a wall of calluses it can be easily stripped off from surface of normal kidney but if kidney is inflamed it cannot be stripped off as it is firmly attached to the kidney perirenal or perinephric fat it is a layer of adapost tissue between fibrous capsule and renal fascia it is thickest at the borders of kidney and is prolonged through hilum and fills up the extra space in the renal sinus in chronic debilitating diseases kinking of ureter is seen due to depletion of perinephric fat which causes downward displacement of kidney and compresses the urer renal fascia it is also known as false capsule or fascia of geroda it is a fibro aralar sheath surrounding kidney and perirenal fat it has two layers fascia of TLT IL defined anterior layer fascia of Zucker candle well-defined posterior layer superiorly two layers fuse at the upper end of kidney and resplit to enclose suprarenal gland in separate compartment and then fuse with each other and continue with diaphragmatic fascia inferiorly two layers remain separate and enclose your rer anterior layer is gradually lost in extra peronal tissue of iliac fosa while posterior layer merges with fascia ilaka laterally two layers unite firmly and become continuous with fascia transversalis medially anterior layer passes in front of kidney and renal vessels and blends with connective tissue surrounding the iorta posterior layer runs behind the kidney and is attached to Seas fascia and quadratus lumborum fascia pararenal or par anric fat it lies between renal fascia and anterior layer of thoracal Lumbar fascia and contains fat with more abundant posteriorly and towards the lower pole of kidney it acts like a cushion for the kidney macroscopic structure kidney contains outer cortex and inner Medela cortex it is located below renal capsule and is granular in appearance it is divided into renal columns and cortical arches cortical arches extend as caps between bases of the pyramids and surface of kidney renal columns extend to renal sinus between adjacent pyramids Medela it contains 5 to 11 striad dark and conical masses known as renal pyramids each Pyramid has a base directed to Cortex and Apex which projects into minor calluses as renal papula each pyramid along with overlying cortical Arch forms lobe of kidney renal sinus it is a cavity within the kidney and communicates outside the medial border through hilum it contains renal vessels lymphatics and nerves perinephric fat renal pelvis major and minor calluses renal pelvis within the sinus is divided into two or three large branches known as major calluses which further divides to form 5 to 11 shorter branches known as minor calluses minor calluses have cup shaped depression at outer ends to receive renal papilla microscopic structure each kidney consists of 1 to 3 million urine Aeris tubules the functional unit of the kidney is the nephron each kidney contains approximately 1 million nephrons each with a renal Corpus CLE and a renal tubule the renal Corpus CLE is composed of a TFT of capillaries called the glomus surrounded by the Bowman's capsule the renal tubule is divided into several segments in the following order from proximal to distal proximal convoluted to bule proximal straight to bule thin descending limb of loop of Henley thin ascending limb of loop of Henley thick ascending limb of the loop of Henley distal convoluted tubule cortical collecting duct medular collecting duct there are two types of nephrons cortical and juxa medular coral nephrons approximately 85% are located close to the outer part of the renal cortex short Loop of Henley mainly Regulatory and excretory functions jua medular nephrons approximately 15% glomus near the junction of the renal cortex and Medela long Loop of Henley major function is concentration or dilution of urine points to ponder are as follows renal blood flow is normally about 25% of cardiac output renal cortex receives about 90 to 95% of Total Renal blood flow the renal Medela receives 5 to 10% of the Total Renal blood flow arterial Supply arterial Supply to kidney is from renal artery renal arter Aries arise as direct branches of abdominal aorta between L1 and L2 vertebra just below the origin of superior mesentric artery accessory renal arteries are present in 30% of individuals they also Branch laterally from the iorta and enter at the hilum the renal arteries gives off branches to the adrenal gland inferior suprarenal artery and urer left renal artery runs behind the left renal vein whereas the right renal artery runs behind inferior vena and right renal vein each renal artery divides into anterior and posterior divisions at or near the hilum of kidney anterior division supplies a picle upper middle and lower segments and posterior division supplies posterior segment via segmental arteries each segmental artery divides into lowbar branches after supplying renal sinus lowbar arteries further divide into two or three interlobar arteries which pass between pyramids each interlobar artery divides dichotomously into arcuate artery as they reach the base of associated pyramid and run parallel to the surface of kidney between pyramids and overlying CeX each arcuate artery gives many interlobular arteries which pass radially toward the surface of kidney interlobular arteries give efferent arterials which pass to the capillaries of glomi and then reunite to form eant arterial eant arterials divide to form peritubular capillary plexus around convoluted tubules renal blood flow renal artery anterior and posterior branches segmental arteries lowbar arteries inter lowbar arteries two arcuate arteries interlobular arteries efferent arterial glomus ENT arterial vasera to the Venus system coming to the Venus drainage Venus blood from kidney is drained by renal veins a single vein exits each kidney at the hilum anterior to the renal artery and drains into the inferior vinaa the left renal vein is longer than the right because it run runs longer course to the inferior vena which is situated on the right side of the body left renal vein crosses the midline between the iorta and the superior mesentric artery left suprarenal and gonadal veins drain into the left renal vein whereas on the right they drain into the venina ca lymphatic drainage lymphatics from kidney drain into paraortic lymph nodes at the level of the origin of renal arteries nerve Supply nerve Supply to kidney is from renal plexus which contains both sympathetic and parasympathetic fibers renal plexus reach kidney along renal artery sympathetic fibers are derived from T10 to L1 spinal segments and parasympathetic fibers are derived from the Vagas nerves