Describe the internal structure of a nephron.

(N/A) Each nephron consists of two major parts:
$(1)$ Malpighian body (Renal corpuscle) and $(2)$ Renal tubule.
$(1)$ Malpighian body: It is a complex structure formed by the glomerulus and Bowman's capsule.
$(i)$ Glomerulus: It is a tuft of capillaries formed by the afferent arteriole,which is a fine branch of the renal artery. Blood from the glomerulus is carried away by an efferent arteriole. The diameter of the efferent arteriole is smaller than that of the afferent arteriole,which helps in creating the pressure required for filtration.
$(ii)$ Bowman's capsule: It is a cup-shaped,double-walled sac that encloses the glomerulus. The outer wall is formed of squamous epithelium,while the inner visceral layer contains specialized cells called podocytes. These cells are arranged in an intricate manner to leave some spaces called filtration slits or slit pores,which allow for the filtration of blood.
$(2)$ Renal tubule: The tubule begins with a proximal convoluted tubule $(PCT)$,followed by the Henle's loop,which is a hairpin-shaped structure with descending and ascending limbs. The ascending limb continues as a highly coiled distal convoluted tubule $(DCT)$.
- The $DCTs$ of many nephrons open into a straight tube called the collecting duct.
- Many collecting ducts converge and open into the renal pelvis through the medullary pyramids in the calyces.
- Urine formation occurs in the nephron,while the collecting duct primarily transports and concentrates the urine before it is eliminated.