Question

Effective net filtration pressure in the glomerulus in kidney of man is about
A. +75 mm Hg
B. +80 mm Hg
C. +20 to 25 mm Hg
D. +50 mm Hg

Answer 1

Hint: Nephron is a tiny functional and structural unit of kidney.
There are 1 million nephrons per kidney
It is 3 cm in size
It consists of:
1. Renal tubules.
2. Glomerulus.

Complete answer:
In order to solve this question, we need to know more about nephrons and kidneys.
Nephrons are complex structures in the kidney.
Structure of nephron includes:
- Renal corpuscle
- Proximal convoluted tubule
- Loop of henle
- Distal convoluted tubule
Their main function is excretion and urine formation.
Urine formation is a complex mechanism.

It involves three processes:
- Ultra filtration or glomerular filtration
- Tubular or selective resorption
- Selective secretion or augmentation.

Excretion = ultra filtration – reabsorption + secretion.
Ultra filtration is a passive process occurring through a filtration membrane.
Effective filtration pressure is the final force of water and solute across the membrane of glomerulus.

Effective filtration pressure which causes ultrafiltration is determined by three pressures i.e.:
- Glomerular blood hydrostatic pressure: It is due to difference in diameters of afferent and efferent arterioles (GHP) = 60mm of Hg.
- Blood colloid osmotic pressure: It is due to plasma protein albumin which resist further filtration (BCOP) = 30 mm of Hg.
- Capsular hydrostatic pressure: It is the pressure exerted by the wall of the capsule to resist further filtration (CHP) = 20mm of Hg.
Effective of net filtration pressure
$\left ( \dfrac{EFP}{NFP} \right )= GHP-\left ( BCOP+CHP \right )$
                                               = 60-(30+20)
                                               = 60-50
                                               = 10mm Hg
Effective filtration pressure can be 25 because in the previous record GHP = 75 and BCOP = 20 so, if 10 is not an option choose 25mmHg.

So, the correct option is C. 20 to 25 mm of Hg.

Note: Kidney is an important organ in the human body which helps in excretion of waste products out from the body.
If any sort of problem occurs in the kidney it leads to many kidney related diseases.
Type of kidney diseases is:
- Acute Glomerulonephritis
- Nephrotic syndrome
- Acute renal failure
- Chronic renal failure