List the three primary plasma proteins and describe their functions and relative quantities.

Here are the three primary plasma proteins, from largest to smallest quantity, and their functions:

1. Albumin:

   • Quantity: Most abundant plasma protein.
   • Function: Primarily responsible for maintaining the osmotic pressure of plasma, which helps regulate fluid balance between blood and tissues. It also acts as a transport protein for fatty acids, thyroid hormones, and some steroid hormones.

2. Globulins:

   • Quantity: Second most abundant.
   • Function: This is a diverse group. Immunoglobulins (antibodies) are a type of globulin crucial for the immune system, defending against pathogens. Other globulins act as transport proteins for lipids, fat-soluble vitamins, and metal ions.

3. Fibrinogen:

   • Quantity: Least abundant of the three primary proteins.
   • Function: Essential for blood clotting. When activated, fibrinogen is converted into fibrin, which forms the meshwork of a blood clot.