Question

Match each description with a component of blood in the key. Answers can be used more than once. a. red blood cells b. white blood cells c. red and white blood cells and platelets d. plasma Formed elements

Short answer

The components of blood were matched to their descriptions as follows: Description 1: a - Red blood cells Description 2: b - White blood cells Description 3: c - Red and white blood cells and platelets Description 4: d - Plasma

Step-by-step solution

Description 1: Red blood cells

Red blood cells (also known as erythrocytes) are primarily responsible for the transport of oxygen and carbon dioxide to and from the cells of the body. The answer for this description is a - 'red blood cells'.

Description 2: White blood cells

White blood cells (also known as leukocytes) are responsible for the immune response and defense against bacteria, viruses, and other infections in the body. The answer for this description is b - 'white blood cells'.

Description 3: Red and white blood cells and platelets

Red blood cells, white blood cells, and platelets are all considered complete blood cells, as they each serve a unique function within the body. Platelets are responsible for blood clotting and wound healing. The answer for this description is c - 'red and white blood cells and platelets'.

Description 4: Plasma

Plasma is the liquid part of the blood composed mostly of water, but also containing proteins, electrolytes, nutrients, and waste products. Plasma acts as a carrier for various substances in the body, including hormones, gases, nutrients, and waste products. The answer for this description is d - 'plasma'.

Summary

In this exercise, the components of blood were matched to their descriptions as follows: Description 1: a - Red blood cells Description 2: b - White blood cells Description 3: c - Red and white blood cells and platelets Description 4: d - Plasma

Key concepts

Red Blood Cells

Red blood cells, also known as erythrocytes, are a vital component of blood. They play a key role in transporting oxygen from the lungs to the rest of the body and returning carbon dioxide from the body back to the lungs for exhalation. This oxygen transport is possible due to a protein called hemoglobin, which is rich in iron and binds oxygen molecules.
Red blood cells have a unique disc-like shape that increases their surface area, enhancing their ability to exchange gases efficiently. They are produced in the bone marrow and have a lifespan of about 120 days before they are recycled by the body.

• Function: Oxygen and carbon dioxide transport
• Shape: Disc-like for efficient gas exchange
• Production: Occurs in the bone marrow
• Lifespan: Approximately 120 days

Understanding the role of red blood cells is crucial in appreciating how oxygen travels throughout our body, fueling every cell and supporting vital functions.

White Blood Cells

White blood cells, or leukocytes, are the defenders of our body. They are a crucial part of the immune system, responsible for protecting the body against infections and diseases. Unlike red blood cells, white blood cells are not limited to the bloodstream; they can move through vessel walls to reach affected areas.
There are several types of white blood cells, each with a unique function:

• Lymphocytes: Include B-cells and T-cells which are essential for adaptive immunity.
• Neutrophils: Act as first responders to infections by engulfing pathogens.
• Monocytes: Transform into macrophages to digest dead cells and bacteria.
• Eosinophils and Basophils: Involved in combating allergies and parasitic infections.

The diverse functions of white blood cells highlight their importance in maintaining health and defending against infections.

Plasma

Plasma is the liquid component of blood, making up about 55% of its overall content. It serves as a crucial transport system within the body, carrying nutrients, hormones, and waste products to where they need to go. Composed mostly of water, plasma also contains proteins, electrolytes, and other essential substances.
Plasma proteins fulfill various roles:

• Albumin: Helps maintain the body's osmotic balance.
• Globulins: Involved in immune responses.
• Fibrinogen: Plays a key role in blood clotting.

Plasma is instrumental in keeping blood pressure stable and ensuring that cells receive the nutrients they require.
Furthermore, by carrying carbon dioxide and waste products, it supports the body in maintaining homeostasis. Plasma's ability to transport diverse substances underlies many physiological functions.

Platelets

Platelets, or thrombocytes, are small cell fragments crucial for blood clotting. When bleeding occurs due to a cut or injury, platelets rush to the site and form a clot to prevent excessive blood loss. This process is known as coagulation.
Functioning alongside clotting factors in plasma, platelets adhere to the walls of the blood vessels, activating more platelets to form a solid blockage in the wound. This leads to cessation of bleeding and starts the process of wound healing.

• Primary role: Blood clotting and prevention of blood loss
• Process: Adhering to injured vessel walls to form clots
• Collaboration: Works with plasma clotting factors

The aggressive response of platelets to injury is vital for maintaining the integrity of the circulatory system and ensures that injuries do not result in critical blood loss.