Q.Describe the structure of a human kidney with the help of a labelled diagram.

The human kidney can be described part by part, as it would appear in a labelled diagram.

• Overall shape and position: reddish-brown, bean-shaped, lying against the back inner wall of the abdominal cavity, about 10-12 cm long, 5-7 cm wide and 2-3 cm thick.
• Hilum: a notch on the inner concave surface where the ureter leaves and blood vessels and nerves enter.
• Renal pelvis and calyces: a funnel-shaped chamber just inside the hilum, with finger-like extensions called calyces. …

Since this cannot be drawn here, the kidney's structure can instead be described feature by feature, exactly as it would appear labelled in a diagram.

• Shape and position: the kidneys are reddish-brown, bean-shaped organs lying against the back inner wall of the abdominal cavity, roughly between the last thoracic vertebra and the third lumbar vertebra. In an adult, each is about 10 to 12 centimetres long, 5 to 7 centimetres wide and 2 to 3 centimetres thick, weighing on average 120 to 170 grams.
• Hilum: a notch on the inner, concave surface of the kidney, through which the ureter leaves and blood vessels and nerves enter.
• Renal pelvis and calyces: just inside the hilum lies a broad, funnel-shaped chamber called the renal pelvis, whose finger-like extensions are called calyces; these collect urine draining from the medullary pyramids.
• Capsule: a tough outer covering wrapping the whole kidney.
• Cortex and medulla: beneath the capsule, the tissue is organised into an outer cortex and an inner medulla. The medulla is broken into several cone-shaped medullary pyramids, whose tips project into the calyces. …

Method: Macro-to-Micro Organ Description

Use this method for any "describe the structure of [organ]" question — build the description in layers, from what you'd see from the outside first, down to the microscopic functional units, rather than listing features in random order.

Steps

Step 1: Describe external shape, size and position first

Begin with what is visible before any dissection: overall shape (bean-shaped), approximate size, colour, and where in the body it sits (against the back wall of the abdominal cavity, one on either side of the spine). This orients the reader before any internal detail is introduced.

Step 2: Describe the single distinguishing external landmark

Name the one feature that connects the organ to the rest of the system — for the kidney, the hilum, the notch on the inner concave surface where the renal artery enters, the renal vein leaves, and the ureter exits. This landmark is usually where a question expects you to explain how the organ connects to its blood supply and drainage.

Step 3: Cut inward and describe the internal zones, outer to inner …