Renal Anatomy for 3 Levels PDF

Renal anatomy (Kidney) Dr.Mohammed Alshamiri Senior Specialist of Urology Fellowship of Genitourinar reconstructive surgery-  Talk about Overview of renal system Function of kidney General urinary system Number, site, size, part of kidney...

Renal anatomy (Kidney) Dr.Mohammed Alshamiri Senior Specialist of Urology Fellowship of Genitourinar reconstructive surgery-  Talk about Overview of renal system Function of kidney General urinary system Number, site, size, part of kidney surface anatomy ant, post Relation, ant. Post, Hilum of kidney‫ و‬Identification the side Renal fascia, renal segment Strictur of kidney,general and microscopic Blood supply, artery, vein, nerve, lymphatic  Functions of kidney The kidneys serve important functions, including filtration and excretion of metabolic waste products (urea and ammonium); regulation of necessary electrolytes, fluid, and acid-base balance; and stimulation of red blood cell production. They also serve to regulate blood pressure via the renin-angiotensin-aldosterone system, controlling reabsorption of water and maintaining intravascular volume. The kidneys also reabsorb glucose and amino acids and have hormonal functions via erythropoietin, calcitriol, and vitamin D activation Kidney functions  Peritoneal Covering The kidney is a retroperitoneal structure (means that its posterior surface is not covered by peritoneum)  Number and Size Typical kidney (Weighs about 150 gm it is one on each side (12 x 6 x 3 cm).  Site situated on the posterior abdominal wall, extending from upper border of TI 2 to L3 vertebra, Parts of the kidney Hilum of the kidney  Hilum of the kidney The hilum is the point of entry of the renal vessels. it contains the following 1. Renal vein (anterior). 2. Renal artery (intermediate). 3. Pelvis of the ureter (posterior + downwards). Identification of the Side 1. The hilum is directed medially. 2. The renal vessels are anterior to the urete 3. The ureter is directed downwards. Surface anatomy Surface anatomy  Surface anatomy Anterior S.A. 1. Upper end. At the lower border of the 11the rib ( Lt.. side) or (Rt. side level of T12). 2. Lower end. At the level of the subcostal plane level of L3). 3. Hilum at the level of L1  Surface Anatomy Posterior S. A(morries rectangule) 1-Upper horizontal line at the level of the spineT11 2-lower horizontal line of the level of the spine of L3 3-medial vertical line 1 inch(2.5cm) lateral to the median plane 4- lateral vertical line 3.5 inches(9cm) lateral to the median plane  Relations anterior relation Ant. relation Relations Posterior relation  Posterior relation Four muscles 1-Diaphragm (behind tbe upper pole and separates tbe kidney from the pleura). - On Rf. side, it separates tbe kidney from the last rib and last intercostal (Rt kldney) is lower than the left kidney)' because the right kidney is pushed downwards by tliver). - On lt. side, it separates the kidney from the last rlb, last intercostal space and 11 rlb. b. Psoas major (behind tbe medial part C. Quadratus lamborum(behind the intermediate part) d. Transversus abdomisis muscle (behind thc lateral part Four small stricture They lie between the posterior surface of tge kidney and. quadratus lumborum 1-subcostal veseles 2.subcostal nerve 3-illiohypogastric nerve 4-ilioinjuinal nerve  Q. ? The anterior surface is totally covered by peritoneum EXCEPT for: Areas related ta suprarenal glands and large intestine (both sides) Area related to the duodenum (right kidney) Area related to pancreas and splenic artery (left kidney). Posterior relation Renal fascia  Renal fascia Kidneys are protected and stabilized by 4 layers 1. Fibrous capsule A layer of collagen fibers. Covers outer surface of entire organ 2. Perinephric fat. A thick layer of adipose tissue. Surrounds fibrous capsule 3. Renal fascia. A dense fibrous outer layer. Anchors kidney to surrounding structures  Clinical important of renal fascia. 1-Sudden loss of weight may cause descent (ptosis) of the kidney due to diminished amount of the perinephric fat. 2. Pus around the kidney spreads downwards as is filled with loose areolar connective tissue. Renal Segments  Renal segments According to the vascular pattern, each kidney subdivided to 1-apical segment(appears on the ant. and post surface 2-inferior segment (appears on the ant. and post surface 3-superior segment(appears only on the ant. 4-middle segment (appears only on the ant. Stricture of the kidney Outer Cortex Inner medulla Renal segments vascular supply  Blood supply to the kidney The kidneys receive approximately 20% of the cardiac output. The blood supply to the kidneys arises from the paired renal arteries at the level of L2. They enter into the renal hilum, the passageway into the kidney, with the renal vein anteriorly; the renal artery; and the renal pelvis posteriorly.  Renal artery The first branch off of the renal artery is the inferior suprarenal artery. The renal artery then branches off into 5 segmental branches. The posterior segmental artery supplies most of the posterior kidney, with the exception of the lower pole. The anterior branches are the superior segmental artery, anterior superior segmental artery,  Renal artery They then radiate into interlobular arteries, which extend into the cortex of the kidney to finally become afferent arterioles, then peritubular capillaries to efferent arterioles. Some of the terminal branches of the interlobular arteries become perforating radiate arteries, which supply the renal capsule. Renal pelvic and superior ureteric branches  Renal veins The renal veins drain the kidneys in a similar distribution, and the renal vein is generally anterior to the renal artery at the hilum. The left renal vein is longer than the right as it crosses the midline to reach the inferior vena cava (IVC). Generally, the left gonadal vein drains into the left renal vein inferiorly, while the left suprarenal vein drains into the  Renal lymphatic The lymphatic drainage parallels the venous drainage system. After leaving the renal hilum, the left primary lymphatic drainage is into the left lateral aortic lymph nodes, including nodes anterior and posterior to the aorta between the inferior mesenteric artery and the diaphragm. On the right, it drains into the right lateral caval lymph  Nephron Nephrons Microscopic functional units of kidneys Each consists of renal corpuscle and renal tubule Each renal tubule empties into collecting system Renal corpuscle - Spherical structure consisting of Glomerular ( Bowman's) capsule. Glomerulus (capillary network)  Glomerular capsule Forms outer wall of renal corpuscle Encapsulates glomerular capillaries Continuous with initial segment of renal tubule.Glomerulus Consists of about 50 intertwined capillaries Blood is delivered by afferent arteriole Blood, leaves through efferent arteriole  Renal tubule Renal tubule - Two convoluted segments. Proximal convoluted tumult (PCT). Distal convoluted tubule (DCT) Segments are separated by nephron loop (loop of Henle). U-shaped tube. Extends at least partially into medulla - Proximal convoluted tubule (PCT) - First segment of renal tubule - Simple cuboidal epithelium. Microvilli on apical surfaces - Primary function is reabsorption of ions  Nephron loop Descending limb. Fluid flows toward renal pelvis ,Ascending limb. Fluid flows toward renal cortex Segments of limbs have thick or thin epithelia. Descending thin limb (DTL). Ascending thin limb (ATL). Thick ascending limb (TAL)  Distal convoluted tubule (DCT) Third segment of renal tubule Smaller luminal diameter than PCT Epithelial cells lack microvilli Primary function is to reabsorb water and selected ions. Actively secretes undesirable substances  Juxtaglomerular complex (JGC) Helps regulate blood pressure and nitrate formation Consists of. Macula densa. Juxtaglomerular cells. Extraglomerular mesangial ce  Juxtaglomerular complex 1-Macula densa ' Epithelial cells of DCT, near renal corpuscle. Function as chemoreceptors or baroreceptors 2-Juxtaglomerular cells. Smooth muscle cells in wall of afferent arteriole. Function as baroreceptors and secrete renin 3-Extraglomerular mesangial cells. Located between aafferent and  Collecting system Collecting system A series of tubes that carries tubular fluid away from nephrons -Collecting ducts. Receive fluid from many nephrons Each collecting duct Begins in cortex Descends into medulla. Carries fluid to papillary duct, which drains into a minor calyx  Renal cortex Renal cortex Superficial region of kidney in contact with fibrous capsule Reddish-brown and granular - Renal pyramids - 6 to 18 triangular structures in renal medulla. Base of each pyramid abuts cortex Tip (renal papilla) projects into renal sinus  Renal columns Renal columns - Bands of cortical tissue that separate adjacent renal pyramid-Extend into medulla - Ducts within each renal papilla - Discharge urine into a minor calyx, a cup- shaped drain  Major calyx - Formed by four or lve minor calyces - Renal pelvis Large, funnel-shaped chamber Formed by two or three major calyces Connected to ureter, which drains kidney -