KIDNEY

Kidney

The kidneys are a pair of bean-shaped organs located in the lumbar region of the vertebral column. They are surrounded by the renal fascia, which attaches them to the posterior abdominal wall.

Location

• Situate at the posterior abdominal wall, on either side of the vertebral column.
• Protected by the 11th and 12th ribs.

Structure

• Consist of an outer cortex and an inner medulla.
• The cortex contains the glomeruli and the proximal and distal convoluted tubules.
• The medulla contains the loop of Henle and the collecting ducts.

Function

• Regulates the osmotic pressure of the blood.
• Maintains acid-base balance.
• Removes wastes and excess substances from the blood.
• Regulates the amount of water in the blood.

Blood Supply

• Supplied by the renal arteries, which branch off from the aorta.
• Receive oxygenated blood from the renal arteries.
• Deoxygenated blood is collected by the renal veins and returned to the heart.

Lymph Drainage

• Lymphatic vessels collect lymph from the kidneys and drain it into the lymph nodes.
• The lymph nodes filter the lymph and remove any pathogens or debris.

Development

• The kidneys develop from the intermediate mesoderm.
• The pronephros is the first kidney to form.
• The mesonephros is the second kidney to form.
• The metanephros is the final kidney to form.

Muscle Action Sequence

• The kidneys are innervated by the renal nerves.
• The renal nerves stimulate the smooth muscle in the blood vessels to constrict or dilate.
• This helps to regulate blood flow to the kidneys.

Note

• The kidneys are essential organs that filter the blood and remove waste products.
• Damage to the kidneys can lead to kidney disease or failure. Kidney (MSLV)

The kidney is an essential organ in the urinary system, responsible for filtering waste products and excess fluids from the blood, regulating electrolyte levels, and producing hormones that help control blood pressure.

1. Describe the morphology of the kidney

• The kidney is a bean-shaped organ, approximately 11-12 cm in length and 6-7 cm in width.
• It is divided into an outer cortex and an inner medulla, with the renal pyramids and collecting ducts present in the medulla.
• The renal hilum, where blood vessels and nerves enter and exit, is located on the medial aspect of the kidney.

2. Mention the relations of the kidneys

• The kidneys are located in the retroperitoneal space, between the thoracic vertebrae and the iliac crest.
• They are related to the following structures:
  • Supra: Lower border of the diaphragm
  • Infr: L1-L3 vertebrae
  • Ant: Abdominal aorta
  • Post: Psoas major muscle
  • Med: Aorta and inferior vena cava
  • Lateral: Quadratus lumborum muscle

3. Describe the structure of the kidney in coronal section

• The kidney is divided into three main parts: the renal cortex, the renal medulla, and the renal pelvis.
• The renal cortex contains the renal corpuscles (glomeruli and Bowman's capsule) and the proximal and distal convoluted tubules.
• The renal medulla contains the renal pyramids and collecting ducts.
• The renal pelvis is the funnel-shaped structure that collects urine from the calyces and empties it into the ureter.

4. Describe the blood supply of the kidneys

• The kidneys receive blood supply from the renal arteries, which arise from the abdominal aorta.
• The right renal artery is shorter and arises from the aorta at the level of L1 vertebra.
• The left renal artery is longer and arises from the aorta at the level of L2 vertebra.
• The renal arteries branch into segmental arteries, which further branch into interlobar arteries, then arcuate arteries, and finally, the afferent arterioles.

5. Explain the applied anatomy

• The kidneys are a common site for various pathologies, such as kidney stones, infections, and tumors.
• The renal arteries are a common site for atherosclerotic plaques, which can lead to renal artery stenosis.
• The kidneys are also a common site for biopsy, which can be performed percutaneously or through an open surgical approach.
• Knowledge of the renal anatomy is essential for surgeons performing renal transplantation, nephrectomy, or pyeloplasty.