Question

Where in the kidney is the renal medulla?

Answer 1

Renal medulla is a light red colored inner side found in the inner side of the cortex next to the renal pelvis. Some parts of the cortex entering the medulla form a type of column known as the renal column or the column of Bertini. Regulation of the concentration of the urine is among the main functions of the renal medulla.

Complete answer:
Kidneys are a pair of organs found in the anterior part of the abdominal cavity below the diaphragm. The main function of the kidney includes the removal of metabolic wastes outside the body. Each kidney is a bean-shaped structure of definite length, width, and thickness. It is covered with the help of connective tissue known as the renal capsule, protecting them from injury. Around the renal capsule, there is a layer of adipose tissue and another fibrous membrane is present on the outside known as the renal fascia. The fascia anchors to the abdominal wall. The inner side of the kidney is a concave type and contains a depression in the middle known as the hilum. From the hilum, the renal arteries come in am=nd the ureter and the renal vein emerges out of the kidney.
Now if we come to the internal structure of the kidney, next to the hilum there is a presence of a central cavity known as the renal sinus. The renal pelvis is the upper expanded funnel-shaped end of the ureter. The renal pelvis is divided into $2 - 3$ large branches known as major calyx which is further divided into smaller calyces known as the minor calyx. Next to this pelvis the kidney can be divided into two parts – the outer part is dark red colored known as the renal cortex and the inner part is the light red region known as the renal medulla.

Note. :
The structural and functional unit of the kidney is a nephron. Millions of nephrons are found in the kidney. Nephrons can be of two types – a. cortical nephron – Their Malpighian corpuscles are located in the outer $2/3$ rd of the cortex and the loop of Henle just hangs in the medulla and b. juxta-medullary nephrons – Malpighian corpuscles are in the inner third of the cortex and the loop of Henle is embedded deep into the renal medulla.