Problem 6 - Anatomy and Physiology of Animals

Question

Which of the following statements about albumin is true? a. It draws water out of the blood vessels and into the body's tissues. b. It is the most abundant plasma protein. c. It is produced by specialized leukocytes called plasma cells. d. All of the above are true.

Step-by-Step Solution

Answer

Option (b) is true: Albumin is the most abundant plasma protein.

Step 1: Eliminate Incorrect Options

First, we need to identify which options are incorrect. Option (a) suggests albumin draws water out of the blood vessels into the tissues, which is incorrect. Albumin actually helps maintain osmotic pressure in the blood, keeping water in the blood vessels. Option (c) states that albumin is produced by plasma cells, but plasma cells produce antibodies, not albumin.

Step 2: Validate Correct Option

Now we verify which statement is true about albumin. Albumin is indeed the most abundant plasma protein, responsible for maintaining osmotic pressure. Thus, option (b) is correct.

Step 3: Check for All Correct Options

Option (d) states that all of the statements are true, which is incorrect as we identified that options (a) and (c) are false. Therefore, option (d) can be eliminated as the correct choice.

Key Concepts

Plasma protein

Albumin is a crucial type of plasma protein, which are proteins present in the plasma portion of the blood. Plasma proteins play several important roles in the body, such as maintaining blood pH, immune functions, and blood clotting. Among these proteins, albumin stands out.

Albumin is the most abundant plasma protein, making up about 60% of the total protein in blood plasma.
Here are a few reasons why albumin is vital:

• It helps transport hormones, vitamins, and drugs throughout the body.
• It serves as a buffer to help maintain pH balance in the blood.
• It is integral in maintaining the osmotic pressure necessary for proper fluid balance in the body.

The primary function of albumin, however, is to maintain the osmotic pressure of blood, keeping fluids where they should be.

Osmotic pressure

Osmotic pressure refers to the force exerted by the solutes in a solution to draw in water across a semipermeable membrane. In the context of blood, plasma proteins like albumin play a crucial role in regulating osmotic pressure.

Here's how it works:

• Albumin molecules are large and retain water molecules in their vicinity.
• This retention creates a pressure that prevents the fluid from leaking out of the blood vessels into surrounding tissues.
• This pressure is crucial in preventing edema, which is swelling caused by fluid accumulation in tissues.

By maintaining osmotic pressure, albumin ensures that water remains in the vascular system, keeping the blood volume and pressure stable.

Blood vessels

Blood vessels are structures that carry blood throughout the body. They include arteries, veins, and capillaries, each serving different functions but contributing to the overall circulation system.

Here’s a closer look at how blood vessels work together:

• Arteries carry oxygenated blood away from the heart to the tissues.
• Veins return deoxygenated blood from the tissues back to the heart.
• Capillaries are tiny vessels that connect arteries and veins, allowing exchange of materials like oxygen and carbon dioxide.

Within blood vessels, albumin plays a key role by exerting the osmotic pressure needed to maintain fluid balance. Without the proper function of albumin, blood vessels would struggle to retain enough water, potentially leading to disorders involving fluid imbalance.