- State the components and functions of the lymphatic system
- Trace lymphatic drainage through the major vessels of the lymphatic system.
- Identify the mechanisms that cause movement of lymph through the lymph vessels.
Introduction:
The lymphatic system consists of lymphatic fluid, lymphatic vessels, lymphatic tissue, and lymphatic organs located throughout the tissues of the body. It functions to drain excess interstitial fluid from the tissues, to initiate an immune response against disease by producing and transporting lymphocytes, and to transport dietary lipids absorbed by the gastrointestinal tract into the blood. Lymphatic capillaries extend throughout the tissues of the body among blood capillary beds. Interstitial fluid, similar in composition to blood plasma, leaches from the blood capillaries into the surrounding tissue, bathing the cells and supplying each one with nutrients, oxygen, and water while also removing waste, carbon dioxide, and water. Around 30 liters of fluid enter the arteriolar end of capillaries every day, but only 27 liters return to the venous capillaries. The lymphatic system collects the missing 3 liters from the interstitial space and returns it to the venous system. Let’s explore this system that can be found in so many different places and perform multiple roles!
Assignment
Part 1: Complete the activities on Anatomy.TV for the Lymphatic System and Immunity: Introduction, Vessels and Circulation, Organs and Tissues.
To access Anatomy.TV: Resources tab>Library>Library Resources-Database A-Z>Anatomy.TV>Titles(default tab): Choose Lymphatic system and Immunity>choose assigned sections
You will then work through the material and activities by scrolling down on the right. This will allow you to see and work through all activities for that section.
As you complete the lab activities, have the lab report ready to record data.
Part 2: Complete the lab report.
Lymphatic System Lab Report
- List the 4 components of the lymphatic system described in the introduction. (1 point; 1/4 point each)
- List 3 functions of the lymphatic system. (1.5 points total; 1/2 point each)
Lymphatic System Lab Report
- Components of the lymphatic system: a. Lymphatic fluid: The fluid that circulates throughout the lymphatic system. It is derived from interstitial fluid and contains various substances, including water, proteins, cells, and cellular debris. b. Lymphatic vessels: A network of vessels that transport lymphatic fluid throughout the body. These vessels include lymphatic capillaries, collecting vessels, and lymphatic trunks. c. Lymphatic tissue: Specialized tissues that contain lymphocytes, which are key players in the immune response. Lymphatic tissue includes lymph nodes, tonsils, adenoids, spleen, and mucosa-associated lymphoid tissue (MALT). d. Lymphatic organs: Organs that play a crucial role in immune function. The primary lymphatic organs are the bone marrow and thymus, where lymphocytes are produced and matured. The secondary lymphatic organs include lymph nodes, spleen, and MALT, where lymphocytes gather to initiate immune responses.
- Functions of the lymphatic system: a. Fluid balance: The lymphatic system helps maintain fluid balance in the body by collecting excess interstitial fluid that has leaked out of the blood capillaries and returning it to the bloodstream. This prevents the buildup of fluid in tissues and maintains overall fluid homeostasis. b. Immune response: The lymphatic system is crucial for the body’s immune response. Lymphatic organs and tissues house lymphocytes and other immune cells, which detect and eliminate pathogens, foreign substances, and abnormal cells. Lymphocytes produced in the bone marrow and thymus circulate through the lymphatic vessels, allowing them to encounter antigens and initiate immune responses. c. Absorption of dietary lipids: Specialized lymphatic vessels called lacteals located in the small intestine absorb dietary lipids, particularly fats and fat-soluble vitamins. These lipids are packaged into structures called chylomicrons, which enter the lymphatic circulation. Eventually, these chylomicrons are transported into the bloodstream, where they can be utilized by the body.