Olinger Lymphoid Tissue 1 (Non-Encapsulated) (Lecture 2) Flashcards
What are the primary lymphoid organs?
The Thymus (T Cells) and Bone Marrow (B Cells). Primary Lymphoid Organs produce the cellular components of the Immune System
What are the secondary lymphoid organs?
The Adenoids, Lymph Nodes, and the Spleen. Secondary Lymphoid Organs are the locations where the immune responses occur.
What type of tissue is often related to the airway?
Pseudo stratified epithelium.
What is Non-encapsulated (diffuse) lymphoid tissue?
- Diffuse scattering of Lymphoid Cells deep to the epithelium in the connective tissue
- Strategically located in the gastrointestinal tract, genitourinary tract and respiratory passages
What is Non-encapsulated Lymphoid Tissue (Single Nodular Tissue) Primary?
Primary Nodule:
- Far more infrequent than Secondary Nodules.
- Consist of only small lymphocytes
- Prenatal
- Do not possess a germinal center
What is Non-encapsulated Lymphoid Tissue (Single Nodular Tissue) Secondary?
Secondary Nodule:
- Far more frequent than Primary Nodules
- Possesses a germinal center which stains slightly lighter than the outer portion
- Germinal center possesses clusters of lymphoblasts
- Possesses outer ring, or cap, or mantle zone with smaller lymphocytes -Memory cells also collect in the outer ring
What are tonsils?
Tonsils:
-Partially encapsulated aggregates of lymphoid Nodular tissue
What epithelium do Pharyngeal Tonsils have?
- Characterized by pseudostratified columnar ciliated epithelium
What epithelium do the Palatine Tonsils have?
-Characterized by stratified
squamous epithelium
-Possesses a relatively thick
partial connective tissue capsule
-Possesses germinal centers
-Possesses 10 – 15 epithelial
invaginations called Crypts
Tough epithelium. Due to eating food.
What type of epithelium do Lingual Tonsils have?
- Characterized by stratified squamous epithelium
- No well defined capsule
- Possesses germinal centers
- Possesses one crypt per tonsil
What is Mucosa-Associated Lymphoid Tissue (MALT)?
-Single or clusters of lymphoid nodules
-Typically found in the Gastrointestinal Tract,
Respiratory passageways and Urinary Tract.
These surfaces protect the body from an enormous quantity and variety of antigens. The tonsils, the Peyer patches within the small intestine, and the vermiform appendix are examples of MALT.
What is GALT?
Gut-Associated Lymphoid
Tissue (GALT):
-In the Ileum they are called
“Peyer’s patches”
-Characterized by an
abundance of villi
-Single or clusters of
lymphoid nodules
-Characterized by simple
columnar epithelium with
Goblet cells
Where is the GALT located?
-Also present in the
Vermiform Appendix
- NO villi
- Characterized by crypts
-Characterized by simple
columnar epithelium with
Goblet cells
** Also located in the first part of the large intestine near the Cecum.
How do you distinguish peyer’s patches from the vermiform appendix?
They Peyer’s Patches will have crypts WITH villi while the vermiform appendix has no villi.
