1. 33.2 Blood and the Lymphatic System
Lesson Overview
33.2 Blood and the Lymphatic System

2. BlOOD
Plasma
Red Blood Cells
White Blood Cells
Platelets

3. The Lymphatic System
What is the function of the lymphatic system?

4. The Lymphatic System What is the function of the lymphatic system?
The lymphatic system is a network of vessels, nodes, and organs that collects the lymph that leaves capillaries, “screens” it for microorganisms, and returns it to the circulatory system.

5. The Lymphatic System
As blood passes through capillaries, some blood cells and components of plasma move through capillary walls and into the fluid between cells, carrying nutrients, dissolved oxygen, and salts.

6. The Lymphatic System
Most of this fluid, known as lymph, is reabsorbed into capillaries, but not all of it. The rest goes into the lymphatic system, a network of vessels, nodes, and organs that collects the lymph that leaves capillaries, “screens” it for microorganisms, and returns it to the circulatory system.
The lymphatic system is also involved in the absorption of nutrients and in immunity.

7. Role in Immunity
Hundreds of small bean-shaped enlargements—called lymph nodes— are scattered along lymph vessels throughout the body.
Lymph nodes act as filters, trapping microorganisms, stray cancer cells, and debris as lymph flows through them. White blood cells inside lymph nodes engulf or otherwise destroy this cellular “trash.”