What is Plasma in Human Blood?

• Human blood plasma is the liquid component of blood, constituting about 55% of its total volume.
• It is a pale yellowish fluid that carries various substances throughout the body, including nutrients, hormones, electrolytes, antibodies, and waste products.
• Plasma plays a crucial role in maintaining homeostasis and transporting essential components to tissues and organs.

Composition:

• Water: Approximately 90% of plasma consists of water, making it the primary solvent for carrying dissolved substances.
• Proteins: Plasma contains a variety of proteins, including albumin, globulins, and fibrinogen. These proteins perform functions such as maintaining osmotic pressure, transporting lipids and hormones, and aiding in blood clotting.
• Electrolytes: Plasma contains ions such as sodium, potassium, chloride, calcium, and bicarbonate, which help regulate fluid balance, pH, and nerve function.
• Nutrients: Glucose, amino acids, lipids, and vitamins are transported in plasma and provide energy and building blocks for cells.
• Waste Products: Metabolic waste products, such as urea, creatinine, and bilirubin, are transported in plasma to be eliminated from the body.
• Hormones: Hormones produced by endocrine glands are carried in plasma to target tissues, where they regulate various physiological processes.
• Gases: Oxygen and carbon dioxide are transported in plasma, primarily bound to hemoglobin in red blood cells.

Functions:

• Plasma carries nutrients, gases, hormones, and waste products to and from cells throughout the body.
• Plasma helps regulate fluid balance, electrolyte concentrations, pH, and temperature.
• Antibodies and immune cells in plasma help defend against pathogens and foreign substances, contributing to the body’s immune response.
• Plasma proteins such as fibrinogen play a crucial role in blood clotting, helping to stop bleeding and repair damaged blood vessels.
• Plasma buffers changes in pH by absorbing or releasing hydrogen ions, helping maintain the body’s acid-base balance.

PYQ:

[2011] A married couple adopted a male child. A few years later, twin boys were born to them. The blood group of the couple is AB positive and 0 negative. The blood group of the three sons is A positive, B positive, and O positive. The blood group of the adopted son is-

(a) O positive

(b) A positive

(c) B positive

(d) Cannot be determined based on the given data