The Lymphatic System

Lymphatic Vessels

An intricate system of drainage vessels that collect excess interstitial fluid and return it to the bloodstream.

Lymph Capillaries

Permeable vessels with flaplike minivalves and collagen filaments that allow fluid uptake.

Lymphedema

Localized swelling due to compromised lymphatic system, caused by node removal or blockage.

Lymph Transport

From lymphatic capillaries to collecting vessels to trunks to lymph ducts.

Lymphatic Collecting Vessels

Thinner-walled vessels with valves that anastomose and resemble veins.

Lymph Trunks

Major trunks like lumbar, bronchomediastinal, subclavian, jugular, and intestinal.

Right Lymphatic Duct

Drains lymph from the right upper arm, head, and chest.

Thoracic Duct

Larger duct receiving lymph from the rest of the body, starting as the cysterna chyli.

Lymphangitis

Inflammation of lymphatic vessels causing visible red, tender areas on the skin.

Lymphatic System Function

No pump; relies on skeletal muscle action, thoracic pressure changes, and valves for fluid movement.

What do lymph nodes do?

Where is the thymus located?

The thymus is located in the upper part of the chest, behind the breastbone and between the lungs.

How does the size of the thymus change with age?

Thymus decreases in size and activity with age, leading to a decline in immune function and T cell production.

Describe the structure of the thymus.

Located in the chest, above the heart. Divided into lobes with a cortex containing T cells and a medulla with Hassall's corpuscles.

What does the cortex of the thymus contain?

Cortex of the thymus contains developing T cells, epithelial cells, and dendritic cells.

What does the medulla of the thymus contain?

The medulla of the thymus contains mature T cells, dendritic cells, and epithelial cells.

What does the thymus secrete?

Thymus secretes thymosin hormones that help in the maturation of T-lymphocytes, a type of white blood cell crucial for the immune system.

What does thymosin do?

A hormone that regulates the immune response and aids in the maturation of T cells.

What is pure red cell aplasia?

Condition characterized by the failure of bone marrow to produce red blood cells, leading to severe anemia.

What is hypogammaglobulinemia?

Hypogammaglobulinemia is a condition characterized by low levels of gamma globulins in the blood, leading to weakened immune function and increased susceptibility to infections.