Kidneys (1st Lecture) PDF - Spring 2024

URS 301 Academic year: Spring 2024 Presentation title Mirjam Nilsson Dr. Mostafa Mahran Lecturer of Anatomy and Embryology Anatomy department  A picture is worth a thousand words Begin your day with a smile + + ...

URS 301 Academic year: Spring 2024 Presentation title Mirjam Nilsson Dr. Mostafa Mahran Lecturer of Anatomy and Embryology Anatomy department  A picture is worth a thousand words Begin your day with a smile + + + + How to eat the elephant + +  + + Urinary system 301 1st lecture  Intended learning outcomes 01 02 03 Anatomy of Relations of Blood supply of kidneys kidneys kidneys 04 05 06 Renal Embrylogy of Congenital Transplantation Kidneys anomalies of kidneys  Anatomy of the Kidneys The kidney is 3x2x1 inches. lies on the posterior abdominal wall , on each side of the vertebral column, behind the peritoneum (retroperitoneal) The kidney lie opposite the 12th thoracic and upper 3 lumbar vertebrae The left kidney is slightly higher than the right one due to presence of the liver The left kidney reaches the 11th rib ,while the right kidney only to the 11th space  Anatomy of the Kidneys It has medial and lateral borders; anterior and posterior surfaces and upper and lower ends (poles)  Hilum of the Kidney lies at the level of L1 (transpyloric plane) Its hilum lies on the medial border which leads to a space inside the kidney named renal sinus Contents of the hilum: Renal vein anterior Renal artery in the middle Pelvis of the ureter posterior.  Coverings of the kidney from internal to external: 1. The fibrous capsule: In normal kidney can be detached easily from its surface. 2. Perirenal fat 3. Renal fascia which surround the kidney and the suprarenal gland. 4. Pararenal fat which lies behind the kidney. Relations of the kidneys Anterior relations of the kidneys  Posterior relations of the kidneys it is direct relation with the following: Muscles: Diaphragm Psoas major Transversus abdominis Quadratus lumborum Nerves: subcostal and vessels ilio-hypogastric nerve ilio-inguinal nerve  Blood supply of the kidney Renal arteries: They arise from the abdominal aorta at the level of the upper border of the 2nd lumbar vertebra. The right renal artery is longer than the left. The branches of each renal artery are: (1) segmental branches to the kidney (2) branches to renal pelvis and upper part of the ureter (3) inferior suprarenal artery  Blood supply of the kidney Each artery passes behind the following structures:  Blood supply of the kidney, lymph drainage and nerve supply Renal veins: 1. The right renal vein is shorter than the left. It opens into the IVC 2. The left renal vein is longer than the right. It crosses the aorta below the superior mesenteric artery behind the body of the pancreas to open into the IVC. It receives the left suprarenal and the left gonadal(testicular or ovarian) veins. Lymph drainage: Lateral aortic lymph nodes around the origin of the renal artery Nerve supply: renal sympathetic plexus  Structure of coronal section of the kidney Each kidney has: 1. Renal capsule 2. Outer cortex 3. Inner medulla: formed of renal pyramids and renal column 4. Renal pelvis which lies in renal sinus The renal pelvis is divided into about 4 major calyces. Each major calyx divides into 2 minor calyces. Each minor calyx is intended with a renal papilla  Renal Transplantation The iliac fossa on the posterior abdominal wall is the usual site chosen for transplantation of the kidney. The fossa is exposed through an incision in the anterior abdominal wall just above the inguinal ligament. The iliac fossa in front of the iliacus muscle is approached retroperitoneally. The kidney is positioned, and the vascular anastomosis constructed. The renal artery is anastomosed end to end to the internal iliac artery and the renal vein is anastomosed end to side to the external iliac vein Uretero- cystostomy is then performed by opening the bladder and providing a wide entrance of the ureter through the bladder wall.  Embryology of the kidneys Metanephrous( permanent kidney) Source :It consists of 2 types of tubules which are derived from 2 different sources: a) Collecting tubules : derived from ureteric bud b) Excretory tubules: derived from metanephric cap  Embryology of the kidneys Collecting tubules : They are the terminal branches of ureteric bud which arise from terminal part of mesonephric duct The free cranial end of ureteric bud penetrates the metanephric cap and divides there repeatedly to form: 1.Major calyces 2. Minor calyces 3.Collecting tubules of kidney Excretory tubules : Nephrons develop from the metanephric cap which is derived from mesoderm of nephrogenic cord present in pelvis Each metanephric tubule becomes S-shaped , opens by one end into the collecting tubule while the other end is invaginated by tuft of capillaries to form bowman’s capsule Metanephric tubule elongates and becomes convoluted to form a complete nephron which is made of 1) Proximal convoluted tubules 2) Distal convoluted tubule 3) Loop of Henle  Blood supply of kidneys During the ascent it obtains its arteries from the nearby arteries ( median sacral , common iliac , dorsal aorta ) As the kidney moves upward, new renal branches are formed , and if any of these vessels persist will lead to accessory (Abberant) renal artery Aberrant( accessory) renal arteries  Congenital anomalies of the kidneys 1) Renal agenesis : failure of metanephric cap to differentiate into a functioning nephron 2) Congenital cystic kidney : due to failure of metanephric tubules to communicate with collecting tubules 3) Congenital pelvic kidney : due to failure of metanephrous to ascend from pelvis to upper lumbar region 4) Horse-shoe kidney: due to fusion of the lower poles of the 2 kidneys across the midline , as the ascent stops below the origin of inferior mesenteric artery 5) Supernumerary kidney: an extra kidney with its own ureter , due to presence of an extraureteric bud 6) Kidney with an accessory renal artery: ( see previous slide)