🥇 Anatomía del RIÑÓN (1/2). ¡Fácil Explicación!

Anatomy of the Kidney: Overview and Structure

Introduction to Kidney Anatomy

• The speaker introduces the topic of kidney anatomy, emphasizing its complexity and the decision to split the discussion into two videos.

• This first video will cover generalities, renal fascia, and key anatomical relationships; deeper structures will be discussed in part two.

Exclusion of Venous Irrigation

• Venous irrigation and drainage are not covered in this series; a separate video titled "Renal Artery and Vein" is dedicated to explaining these topics due to their unique anatomical paths.

Basic Characteristics of Kidneys

• Kidneys are paired organs often referred to as "ren" or "nephro"; while typically two are present, one can survive with just one kidney.

• Their primary function includes ultra plasma filtration, forming urine, which categorizes them within both the excretory and genitourinary systems. They also produce hormones, indicating an endocrine role.

Anatomical Positioning

• Kidneys are retroperitoneal organs located between L1 and L3 vertebrae when standing; however, variations exist based on diaphragm relaxation during cadaver studies.

• The right kidney is generally lower than the left due to pressure from the liver in the upper right abdomen.

Kidney Dimensions and Shape

Size Specifications

• Typical dimensions include a length of 13–14 cm, width of 7–8 cm at its widest point, and anteroposterior depth of 3–4 cm. Weight ranges from 125 to 155 grams.

Structural Features

• The kidneys have a bean-like shape; this description varies by region but commonly refers to their overall form.

Renal Capsule Description

• The outermost layer is known as the renal capsule; it separates easily from healthy kidneys but adheres tightly in pathological conditions.

Orientation and Positioning of Kidneys

Orientation Details

• Kidneys follow an oblique orientation along the psoas major muscle axis. They are positioned medially (internal side facing each other), directed from posterior (back side) to anterior (front side).

Distance Between Poles

Anatomy of the Kidney

Structure and Orientation of the Kidney

• The kidney has two faces: an anterior face that is convex and a posterior face that mirrors this shape.

• It features two edges: a medial edge facing the spine, which is concave with a notch for renal structures, and a longer, convex lateral edge.

• The kidney has two poles: an upper pole in contact with the adrenal gland (endocrine system), resembling a cap, and a lower pole adjacent to psoas major and quadratus lumborum muscles.

Renal Hilum and Sinus

• The medial edge contains the renal hilum, where structures enter and exit; it leads to a fossa known as the renal sinus.

• The renal sinus is crucial for understanding kidney anatomy; further details will be provided in subsequent videos.

Renal Fascia

• Gerota's fascia surrounds the kidney externally. It consists of an anterior leaf that connects across the midline and a non-continuous posterior leaf that transforms into connective tissue near the spine.

• Between the kidney capsule and Gerota's fascia lies perirenal space filled with perinephric fat; outside this fascia is pararenal fat.

Communication Between Renal Spaces

• Most authors agree there is no real communication between left and right renal spaces despite apparent continuity due to connective tissue barriers.

• Infections can spread from one kidney to pelvic regions due to anatomical connections below but are limited above by adrenal gland encapsulation within renal fascia.

Anatomical Relationships

• A sagittal cut shows relationships between kidneys, liver, transverse colon, and surrounding structures. Understanding these relationships aids in comprehending potential infection pathways.

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Renal Anatomy and Relations

Peritoneal Relations of the Kidneys

• The kidneys are retroperitoneal, meaning they lack visceral peritoneum and are only covered by parietal peritoneum on their anterior face.

• The right kidney is in contact with the liver, separated by parietal peritoneum, while its lower portion contacts the small intestine.

• The left kidney has three areas of parietal peritoneum: one in contact with the stomach, another with the spleen, and a third with loops of the small intestine.

• Additional relations include connections to the descending colon and ascending colon through various ligaments and mesocolon structures.

Visceral Relations of the Kidneys

• The upper pole of each kidney is surrounded by adrenal glands; they share a common renal fascia.

• The upper pole of the right kidney relates to the inferior vena cava, although this relationship is not consistently depicted in anatomical atlases.

• The right kidney's anterior face connects to several structures including the liver, duodenum (specifically its descending portion), ascending colon, and loops of small intestine.

• Understanding these relationships requires knowledge of abdominal visceral anatomy as it aids comprehension of renal positioning within larger anatomical contexts.

Posterior Relations

• The left kidney relates to multiple organs including the stomach, pancreas tail, splenic artery/vein, and descending colon.

• A notable image from Netter illustrates posterior relationships: left kidney aligns with ribs 11 and 12 while right kidney aligns only with rib 12.