Blood

Definition

Blood is a vital fluid in the human body, primarily responsible for transporting oxygen and nutrients to cells and removing waste products. It plays a key role in the immune system, helping to fight infections and maintain homeostasis by regulating temperature and pH levels. Blood's composition includes red blood cells, white blood cells, platelets, and plasma, each contributing to its overall function and significance within major organ systems.

5 Must Know Facts For Your Next Test

1. Blood makes up about 7-8% of an individual's total body weight, with an average adult having around 5-6 liters of blood.
2. The primary function of blood includes transportation of oxygen, carbon dioxide, nutrients, hormones, and waste products.
3. Blood contains two main components: formed elements (cells) and plasma; red blood cells are responsible for oxygen transport while white blood cells are key players in the immune response.
4. The body constantly regulates blood volume and pressure through various mechanisms, including hormonal control and adjustments in heart rate.
5. Different blood types (A, B, AB, O) result from the presence or absence of specific antigens on red blood cells, which is crucial for safe blood transfusions.

Review Questions

• How does blood contribute to maintaining homeostasis within the body?
  • Blood maintains homeostasis by regulating temperature and pH levels as well as ensuring adequate delivery of oxygen and nutrients to tissues. For example, when body temperature rises, blood vessels dilate to increase heat loss through the skin. Additionally, the bicarbonate buffer system in blood helps to maintain a stable pH by neutralizing excess acids or bases that may disrupt the body's balance.
• Discuss the different components of blood and their individual roles in overall health.
  • Blood consists of several key components: red blood cells transport oxygen throughout the body; white blood cells defend against infections and foreign invaders; platelets are essential for clotting to prevent excessive bleeding; and plasma serves as the liquid medium that carries these cells along with hormones, nutrients, and waste products. Each component plays a unique role in maintaining health and supporting bodily functions.
• Evaluate the impact of improper blood transfusion practices on patient outcomes and how blood type compatibility is determined.
  • Improper blood transfusion can lead to severe complications such as hemolytic reactions, where the recipient's immune system attacks transfused red blood cells. This underscores the importance of determining blood type compatibility through testing for specific antigens on red blood cells before transfusion. Ensuring compatibility minimizes risks associated with transfusions and significantly improves patient outcomes by preventing adverse reactions.

Related terms

Hemoglobin: A protein found in red blood cells that binds to oxygen and carries it from the lungs to the rest of the body.

Platelets: Small cell fragments in the blood that are crucial for clotting and preventing excessive bleeding.

Plasma: The liquid component of blood that carries cells, hormones, nutrients, and waste products throughout the body.