High yield information

What is the function of the lymphatic system?

1. Involved in bringing lipids to the circulation. OK, you may be an uber-nerd and already know this, but it's an amazing and often unexepected factoid. Lipids are collected by lacteals (in the villi of the small intestine) and they feed into the lymphatic circulation, depositing their load in the thoracic duct which leads to the subclavian veins.
2. ÒHighwayÓ for lymphocytes to shuttle between lymph nodes and interstitial fluid (fluid between cells) for controlling infections.
3. Helps regulate body fluid distribution, specifically the interstitial fluid.

What is the ``blood'' of the lymphatic system?

Lymph. A colorless fluid similar to plasma which contains proteins (e.g. albumin) and lymphocytes (a type of white cell).

Where does lymph come from?

Lymph comes from the interstitial fluid. Interstitial fluid in turn comes from the intravascular compartment, i.e. blood, which in this setting is most often in capillaries.

Osmotic pressure drives fluid shifts between the intravascular space (capillaries), extravascular space (interstitial space), and lymphatic system. Key players in controlling osmotic pressure are ions (e.g. Na$^{+}$) and proteins (e.g. albumin). Imbalances in fluid distributions in these compartments can result in dehydration, edema (swelling) or other clinical manifestations.

What is the ultimate destination of lymph?

The main thoracic (lymphatic) duct which drains into the subclavian vein.

What glands connect the vast network of lymph vessels?

Lymph nodes

Think of them as watch towers which house the local militia.When inflammatory signals from the interstitial space travel through the lymphatics and toward the nearest lymph node, they signal for them to come out and fight. Just like when your roommate can't stop hooking up with people and gets mono - feel their neck, the nodes will be swollen. Joking aside, mono or infectious mononucleosis, is caused by the Epstein-Barr virus and is referred to as the kissing sickness because of its apparent transmission mechanism among younger adults through saliva.