Anatomy/Lymphatic System

The lymphatic system is a focus topic of the event Anatomy and Physiology. It is expected to rotate in for the 2019 season.

Overview
The lymphatic system is a network of vessels and nodes that transport lymph throughout the body. It is closely connected with immunity, as lymph contains white blood cells and helps the body fight off infection. Lymph is stored in clumps of tissue called lymph nodes. The lymphatic system consists of primary lymph organs where lymphocytes mature, as well as secondary or peripheral lymph organs that maintain mature naive lymphocytes and facilitate adaptive immunity.

Functions
The lymphatic system functions to:
 * return tissue fluid to the bloodstream
 * transport fats from the digestive system to the bloodstream
 * provide surveillance and defense against disease

Lymphatic Tissue
The three types of lymphatic tissue are:
 * diffuse lymphatic tissue
 * lymphatic nodules
 * lymphatic organs

Relation to Cardiovascular System
Unlike the cardiovascular system, the lymphatic system is a one-way system. The lymph vessels do not form a complete circuit between the lymph organs, and lymph is not "pumped" like blood. The lymphatic system also lacks arteries. However, lymphatic and blood vessels both have the same three tunicas, and valves to prevent backflow. Lymph is moved by contractions of skeletal muscle and other body movements, and leakage from lymphatic vessels enters cardiac vessels to increase blood volume. Likewise, lymph vessels act as a reservoir for cells and fluid that escape the cardiovascular system.

Resources
Lymphatic System on Khan Academy