Untitled Flashcards Set

Components of the Lymphatic System

1. Lymph - a clear fluid containing white blood cells, which bathes the tissues and drains through the lymphatic system into the bloodstream.

2. Lymphatic Vessels - a network of vessels that transport lymph throughout the body.

3. Lymphoid Organs - include lymph nodes, spleen, thymus, and tonsils, which play a role in immune responses.

Functions of the Lymphatic System

1. Fluid Balance - collects excess interstitial fluid and returns it to the bloodstream.

2. Fat Absorption - absorbs fats and fat-soluble vitamins from the digestive system via lacteals.

3. Immune Response - houses lymphocytes that help the body fight infections.

4. Waste Removal - removes cellular waste and other foreign materials from tissues.

Main Ducts Returning Fluid to Cardiovascular System

• Thoracic Duct: drains lymph from the left side of the head, neck, chest, left arm, and both legs. It is located along the spine and empties into the left subclavian vein.

• Right Lymphatic Duct: drains lymph from the right side of the head, neck, right arm, and part of the chest, located near the right subclavian vein.

Return of Lymph to Cardiovascular System

Lymph is returned to the cardiovascular system without a pumping organ through:

• Muscle Contractions: surrounding skeletal muscles compress lymphatic vessels to push lymph upwards.

• Valves: ensure one-way flow of lymph and prevent backflow.

• Respiratory Movements: changes in thoracic pressure assist with lymph flow.

Mini-Valves and Their Function

Mini-valves are specialized structures in lymphatic capillaries that allow larger particles (like proteins and bacteria) to enter while preventing backflow, ensuring effective drainage and immune function.

Unique Structure of Lymph Node

• A lymph node is characterized by an outer cortex and inner medulla that contains germinal centers, which are areas of active lymphocyte production and proliferation.

Germinal Centers Composition

Germinal centers are comprised of B cells and helper T cells, crucial for the adaptive immune response.

Lymphoid Organs Table