Anatomy of the Kidney Quiz

Kidney Surfaces

• The kidneys have an anterior and posterior surface, as well as a medial and lateral border.
• The hilum is the indented area on the medial border, serving as a passageway for the renal artery, renal vein, and ureter.
• The upper pole and lower pole are located at the top and bottom, respectively, of each kidney.

Kidney Location

• Kidneys are located retroperitoneally, situated between the vertebral bodies of T12 and L3.
• The left kidney is generally positioned slightly higher than the right kidney.
• The kidneys lie on the posterior abdominal wall, next to the vertebral column.

Renal Sinus & Hilum

• The renal sinus is a large cavity within the kidney containing the renal pelvis, calyces, and major blood vessels.
• The hilum is the entry/exit point for structures to the kidney, including nerves, vessels, and lymphatic vessels.
• The renal pelvis, calyces, renal veins, and renal arteries are inside the renal sinus.

Renal Cortex & Medulla

• The kidney's outer layer is the cortex.
• The inner layer is the medulla, which contains renal pyramids.
• Blood filtration occurs in the renal cortex.
• Urine formation takes place within the renal pyramids located in the renal medulla.

Blood Supply & Lymph Drainage

• The renal artery supplies blood to the kidney.
• Segmental and interlobar arteries branch from the renal artery to distribute oxygenated blood.
• Lymph vessels follow the arterial vessels.
• Lateral aortic lymph nodes receive the drainage from the kidney.

Anterior Relation of Kidneys

• The right kidney is associated with the right lobe of the liver, the duodenum, the right colic flexure, and the small intestine.
• The left kidney is associated with the spleen, stomach, pancreas, and the left colic flexure.

Posterior Relation of Kidneys

• The right kidney is related to the 12th rib.
• The left kidney is related to the 11th and 12th ribs.
• Structures like the diaphragm, psoas muscles, quadratus lumborum muscles, and the subcostal nerve surround both kidneys.

Renal Fascia & Fat

• Each kidney sits inside a connective tissue layer called renal fascia
• Adipose tissue surrounds the kidney, termed perirenal fat - for protection
• Pararenal fat is another layer of adipose tissue situated further outward.

Kidney Functions

• The renal fascia (Gerota's fascia) secures the kidneys and protects them from trauma.
• The renal fascia positions the kidney relative to other abdominal organs.
• A fibrous capsule encloses the kidney and helps support the kidney mass.
• Perirenal fat protects the kidneys and renal blood vessels.

Adrenal Glands

• Adrenal glands, also called suprarenal glands, are situated atop the kidneys.
• The right adrenal gland is pyramidal-shaped.
• The left adrenal gland is crescent-shaped, which is slightly larger.

Adrenal Gland Location

• Adrenal glands are located on top of each kidney, within the retroperitoneum.
• The right adrenal gland is positioned slightly medial to the kidneys.
• The left adrenal gland is positioned slightly medial to the kidneys.

Adrenal Blood Supply

• Each adrenal gland has connections to three-main arteries.
• The three main arteries are the inferior phrenic, renal, and testicular/ovarian arteries.
• A single vein exits the hilum of each gland to drain into the inferior vena cava (on the right) and the renal vein, (on the left).

Development of Kidneys

• The pronephros is the first kidney to develop and appears in the cervical region.
• The mesonephros is the second kidney and is located in the thoracolumbar region.
• The metanephros is the last to develop and is located in the sacral region.

Kidney Development

• During weeks 5-6, the kidney ascends and rotates. The kidney's final position is in the abdominal area.

Ureter

• The ureter is a muscular tube that carries urine from the kidneys to the urinary bladder.
• The ureter is made up of an abdominal part and a pelvic part.
• Ureteral constrictions are at important sites for potential stone entrapment.

Ureteral Relations

• The ureter passes lateral to the pelvic wall related to the psoas major muscle.
• It is located medial to the pelvic brim, with common iliac vessels.
• In females, the ureter lies in relation to the pelvic wall, near the ovarian fossa. The ureter passes under the uterine artery.

Ureter Blood Supply

• The ureter receives blood supply from branches of the aorta, renal arteries, internal iliac arteries, superior and inferior vesical arteries, and uterine arteries .

Urinary Bladder

• The urinary bladder is a hollow, muscular organ located in the pelvis.
• When empty, the bladder is located in the lesser pelvis.
• when full, the bladder extends into the abdominal cavity.
• The urinary bladder can hold up to 500 milliliters of urine.

Bladder Relations

• The bladder rests anterior to the pelvic diaphragm in females.
• Structures like the vagina and rectum form the posterior boundary.

Bladder Blood Supply

• The bladder is supplied with blood from the superior and inferior vesical arteries, and from the inferior gluteal and obturator arteries.
• The venous return from the bladder occurs through a venous plexus. Veins from this plexus drain into internal iliac veins.

Bladder Nerve Supply

• The bladder receives parasympathetic innervation via the nervi erigentes (S2-S4).
• The bladder has sympathetic innervation.
• Motor control of the external sphincter is by pudendal nerves .

Urethra

• The urethra is the tube that carries urine from the bladder out of the body.
• The urethra has different sections in males and females.
• The male urethra passes through the prostate, membranous, and spongy sections, with various functions throughout.
• The female urethra is much shorter and directly leads from the bladder to the vulva.

Kidney Anomalies

• Kidney anomalies can be categorized by structure, location, number, and blood vessel anomalies.
• Abnormal blood supply, shape defects, or missing kidneys may develop.
• Cysts on the kidneys might form due to genetic conditions.

Urachal Anomalies

• A patent urachus is the most common type of urachal anomaly.
• This is where the urachus, the tube from bladder to umbilicus, doesn't close at birth.
• Cysts and sinuses can also form where the urachus is present.

Bladder Anomalies

• Exstrophy of the bladder, often seen at birth, is a condition where the bladder wall folds outward and is visible externally.
• Duplication of the bladder may occur, resulting from incomplete development.

Urethral Anomalies

• Hypospadias is a common condition where the urethral opening is located on the underside of the penis.
• Epispadias is an uncommon condition presenting as the urethral opening located on the upper surface of the penis.

Ureter Constrictions :

• The ureter has three natural constrictions crucial for preventing urine flow blockage.
• Their locations influence risk zones for ureteric stone entrapment.

Development of Urinary Bladder

• In early weeks, the urorectal septum divides the cloaca into the urogenital sinus (anterior) and anorectal canal (posterior).
• The urogenital sinus gradually develops into the urinary bladder.

Trigone Development

• The mesonephric duct gets absorbed, contributing to the trigone formation of the urinary bladder.

Development of Male Urethra

• Parts of the primitive urogenital sinus develop in specific ways to form the structures of the male urethra.

###Development of Female Urethra

• The female urethra develops from the lower part of the vesico-urethral sinus.

Ureter Surface Marks

• Anatomical locations of ureter surface marks to aid visualization and identification in relation to bony landmarks.

Test your knowledge on the anatomy of the kidneys and their surrounding structures with this comprehensive quiz. From the renal capsule to perirenal fat, gauge your understanding of kidney functions and locations. Perfect for students studying human anatomy.