Lymph, Thymus, Spleen, and Lymph Nodes

Name some types and examples of lymph tissue

Diffuse Lymphatic tissue, nodular unencapsulated lymphatic tissue, peyers patches, tonsils

Describe diffuse lymphatic tissue

It is tissue underlying epithelial cells, with loose CT and a lot of lymphocytes

What are examples of nodular unencapsulated tissue

Lymphatic nodules, form peyers patches and tonsils

What are lymphatic nodules

Clusters of lymphocytes (mostly B cells) in loose CT

What are the parts of a lymphatic nodule

germinal center and corona

Describe germinal center and corona

Germinal center is lighter, where B cells divide, and corona is surrounding are where mature B cells live

Describe peyers patches

A little more eosinophilic, 5 nodules in ileum in small intestine

Describe tonsils

clusters of nodules, more eosinophilic

Describe lymph node structure

an encapsulated cluster of lymph nodules cluster, containing a coretex, medulla, corticomedullary junction, trabeculae, and blood vessels

How does lymph travel through the lymph node

Afferent vessel to subcapsular sinus, to trabeucular sinus, to medullary sinus, to efferent vessel

Describe the cortex of the lymph node

The cortex contains many lymph nodules and is directly inside CT capsule

Describe the medulla of the lymph node

This is the material in the center where things drain, more whitish pinkish, where lymph can be cleaned up

Describe thymus structure

Loose CT capsule divides organ into lobules, which contain the medulla and cortex

Describe medulla of thymus

The medulla is where maturing T cells go to ensure they do not self react, lighter purple

Describe cortex of thymus

The cortex is where T cells develop, and are not exposed to antigen

What are Hassals Corpuscles

Epithelial reticular cells keratinize and cause pockets of dead cells

How do T cells travel out of the thymus

They leave through the corticomedullary junction

Describe spleen structure

has veins, red pulp, white pulp, arteries

What is red pulp and what does it look like

It is kind of pink or white, contains red blood cells and macrophages

What is white pulp and what does it look like

White pulp is eosinophilic and contains WBC like lymphocytes

Describe blood flow through the spleen

Enters through splenic artery, enters trabeculae, central arteries, red pulp, then sheathed arterioles, then travels out through the veins

Where are T cells found in the spleen

PALS (surrounding tissue of germinal centers)

Where are B cells found in the spleen

In germinal centers