Name: Excretion in Human Beings
Uploaded: 2019-07-19
Duration: 2 min 52 s
Description: Kidneys eliminate the toxic nitrogenous wastes generated in the body as a result of metabolism. The liver, too, plays a crucial role in this. Take a sneak peek.

Question

Discuss the labelled diagram of the internal structure of the kidney which is observed by longitudinal section.

Accepted Answer

The longitudinal section through the kidney can be described as follows:
Each kidney is composed of a large cavity called the renal sinus, which contains the renal pelvis. Around the renal pelvis, the medulla and the cortex (superficially) are present. The renal pelvis breaks up into 2 or 3 main divisions known as major calyces (singular- Calyx). Each major calyx further breaks up into eight cup-shaped minor calyces, which terminate into renal papillae.

In the kidney, the reddish-brown cortex occupies the peripheral region around the medulla. It is about 4 mm thick. The medulla is formed by a number of striated conical structures called renal pyramids. The wide bases of the pyramids face the surface of the kidney, and the apices face the sinus. Two or more apices join to form rounded structures termed renal papillae. There are about 12 papillae on average. Each papilla has a small opening called foramina through which urine is transferred into calyces. The cortical parts penetrating between the pyramids are known as renal columns. The pyramids appear striated because the renal tubules and the blood vessels are arranged within them in a straight manner. Each kidney is made up of about one million excretory units called nephrons that remain scattered within the cortex and medulla.

Discuss the labelled diagram of the internal structure of the kidney which is observed by longitudinal section.

Important Questions on Excretory Products and their Elimination

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