Oxygen Myoglobin Dissociation Curve
Anatomy of the kidney
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The kidneys are paired, bean-shaped organs that are 
located behind the abdominal peritoneum, along with the posterior body wall.
Due to the size of the liver, the right kidney is somewhat lower than the left kidney.
- Covering the surface of each kidney is a tough, semi-transparent, connective tissue membrane called the renal capsule. This layer also forms a barrier that protects the kidney from infection.
Continue learning about the kidneys with this urinary system revision guide.
- A large renal artery supplies blood to each kidney. These vessels branch from the descending abdominal aorta.
- The renal artery enters the kidney at the hilum (or hilus), an indented region along the medial border.
- Inside the kidney, the renal artery splits into several smaller arteries, which disperse oxygenated blood throughout the organ.
- Also passing through the hilum are the renal vein and ureter. The renal vein transports blood from kidney to the inferior vena cava, and the ureter conducts urine from the tubular system of the kidney to the urinary bladder.
Internal anatomy of the kidney
- If the front half of the kidney is removed, it becomes possible to see that the inside is divided into three major regions or zones.
- The most external region is referred to as the renal cortex. Numerous tubes and blood vessels located in the cortex make it appear light red and somewhat granular.
- Deep to the cortex is the renal medulla..
- This dark red area (Medulla) is filled with 8-12 prominent renal pyramids. As the name implies, each pyramid is a cone-shaped structure. The expanded base of a pyramid lies adjacent to the cortex and the tapered apex or papilla is oriented toward the medial side of the kidney
- Numerous tubules and ducts make up the pyramids, which gives the pyramids a striated appearance, especially when viewed microscopically.
- Next to the medulla is the renal sinus. This medial pocket contains the large blood vessels that pass in and out of the kidney and the tubes that conduct urine to the ureters and bladder.
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