Bone marrow, lymph nodes, the spleen and the thymus are all part of the lymphatic system. Most lymphatic organs are made of a framework of reticular fibers and reticular cells. However, the thymus is made of epithelioreticular cells instead.

Deep cortex, tertiary cortex, juxtamedullary cortex and paracortical zone are all terms for the same region in a lymph node. The deep cortex is the inner region of the cortex, next to the medulla. Lymphatic nodules are not found in the deep cortex. Lymphatic nodules are found in the outer cortex.

Psammoma bodies are collections of calcium. It is derived from the Greek word "psammos", which means sand. Corpora arenacea refers to the calcifications seen in the pineal gland. Corpora arenacea is nicknamed "brain sand". Hassall's corpuscles are the ring like structures found in the thymus. The spherical structures seen in some prostatic alveoli are called prostatic concretions. Pacinian corpuscles are pressure receptors in the skin.

The spleen has a connective tissue capsule. The invaginations of the capsule into the splenic parenchyma are trabeculae. The parenchyma of the spleen can be divided into the white pulp and the red pulp. The white pulp of the spleen is the lymphatic portion of the spleen. Within the white pulp, splenic nodules are found. Splenic nodules are also called Malpighian corpuscles. The red pulp is made up of the splenic sinuses and splenic cords. The splenic cords are also called the cords of Billroth.

Peyer's patches are large nodules of lymphatic tissue. They are seen in the small intestine.

The spleen has a connective tissue capsule. The invaginations of the capsule into the splenic parenchyma are trabeculae. The parenchyma of the spleen can be divided into the white pulp and the red pulp. The white pulp of the spleen is the lymphatic portion of the spleen. Within the white pulp, splenic nodules are found. Splenic nodules are also called Malpighian corpuscles. The red pulp is made up of the splenic sinuses and splenic cords. The splenic cords are also called the cords of Billroth.

The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Diffuse lymphatic tissue in not encapsulated.

The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Diffuse lymphatic tissue in not encapsulated.

T cells gain their immunocompetence in the thymus.

The spleen has a connective tissue capsule. The invaginations of the capsule into the splenic parenchyma are trabeculae. The parenchyma of the spleen can be divided into the white pulp and the red pulp. The white pulp of the spleen is the lymphatic portion of the spleen. Within the white pulp, splenic nodules are found. Splenic nodules are also called Malpighian corpuscles. The red pulp is made up of the splenic sinuses and splenic cords. The splenic cords are also called the cords of Billroth.

Diffuse lymphatic tissue is non-encapsulated lymphatic tissue. It is found in the gastrointestinal tract, the genito-urinary tract, and the respiratory tract. In the gastrointestinal tract it is referred to as GALT (gut associated lymphatic tissue). In the respiratory tract it is referred to as BALT (bronchi associated lymphatic tissue). Diffuse lymphatic tissue is not found in the central nervous system.

The spleen is involved in destruction of old or damaged red blood cells. Storage of blood occurs in the spleen. In the fetus, the spleen is involved in blood cell formation. Lymphocyte and antibody production occurs in the spleen.

The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Diffuse lymphatic tissue in not encapsulated.

The splenic cords are also called the cords of Billroth.

Bone marrow, lymph nodes, the spleen and thymus are all part of the lymphatic system. Most lymph's are made of a framework of reticular fibers and reticular cells. However, the thymus is made of epithelioreticular cells instead.

The mucosa is the innermost layer of the GI tract. The mucosa consists of a lining epithelium, lamina propria and muscularis mucosae. Gut associated lymphatic tissue (GALT) is found in the mucosa and sometimes extends into the submucosa.

PALS stands for periarterial lymphatic sheath. Periarterial lymphatic sheaths are the lymphocytes which surround the central artery in the spleen.

Deep cortex, tertiary cortex, juxtamedullary cortex and paracortical zone are all terms for the same region in a lymph node. The deep cortex is the inner region of the cortex, next to the medulla.

The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Diffuse lymphatic tissue in not encapsulated.

The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Diffuse lymphatic tissue in not encapsulated.

A secondary lymphatic nodule is characterized by the presence of a germinal center.

The localized concentrations of lymphocytes that are seen in the respiratory tract, genitourinary tract, and gastrointestinal tract are lymph follicles. They are also called lymphatic nodules. The lymphatic tissue in the spleen is called white pulp. The large aggregates of lymphatic tissue in the ileum are called Peyer's patches. A lymph node is an encapsulated lymphatic organ. The random distribution of lymphocytes seen in the lamina propria of the respiratory tract, genitourinary tract, and gastrointestinal tract is called diffuse lymphatic tissue. Diffuse lymphatic tissue in not encapsulated.

Diffuse lymphatic tissue is non-encapsulated lymphatic tissue. It is found in the gastrointestinal tract, the genito-urinary tract, and the respiratory tract. In the gastrointestinal tract it is referred to as GALT (gut associated lymphatic tissue). In the respiratory tract it is referred to as BALT (bronchi associated lymphatic tissue).

Diffuse lymphatic tissue is non-encapsulated lymphatic tissue. It is found in the gastrointestinal tract, the genito-urinary tract, and the respiratory tract. In the gastrointestinal tract it is referred to as GALT (gut associated lymphatic tissue). In the respiratory tract it is referred to as BALT (bronchi associated lymphatic tissue).

The spleen has a connective tissue capsule. The invaginations of the capsule into the splenic parenchyma are trabeculae. The parenchyma of the spleen can be divided into the white pulp and the red pulp. The white pulp of the spleen is the lymphatic portion of the spleen. Within the white pulp, splenic nodules are found. Splenic nodules are also called Malpighian corpuscles. The red pulp is made up of the splenic sinuses and splenic cords. The splenic cords are also called the cords of Billroth.