Lymphatics Flashcards
What is the composition of lymphoid system
lymphocytes, lymphoid organs and lymphatic vessels
What is the composition of the lymphoid organs
Bone marrow Lymph nodes Thymus Spleen MALT
What is the main function of the lymphoid system
It protects the body from pathogens and diseased cells
It is organized into organs and tissues that are functionally unified via blood and lymph vascular systems
Immune System
It is also known as central lymphoid organs
Primary lymphoid organs
It is the site where lymphocytes mature
Primary lymphoid organs
Where is B cells produced
Bone marrow
Where is T cells produced
Thymus
It is also known as peripheral lymphoid tissue
Secondary lymphoid organs
Where are the secondary lymphoid organs distriibuted
blood or lymph
What are the secondary lymphoid organs
lymph nodes
spleen
diffuse lymphoid tissues
It is a small, bean shaped, encapsulated organs located
throughout the body along lymphatic vessels.
Lymph nodes
It serves as filters of lymph
Lymph nodes
It is a dense connective tissue enclosing the node
Capsule
It is the space underneath the capsule that receives the lymph
Subcapsular sinus
It is the connective tissue that extends inward from the capsule
Trabecula
It is the spaces alongside trabeculae in which lymph flows from the subcapsular sinus into the cortex.
Trabecular sinuses
It is the outer region of the node
Cortex
It is the region adjacent to the capsule.
Outer cortex
It is spherical clusters of B lymphocytes.
Nodules
It is the light center where B lymphocytes differentiate to plasma cells
Germinal Center
It is the region between the outer cortex and the medulla that is free of nodules.
Inner cortex (paracortex)
The inner part of the node
Medulla
It contains antibody
secreting plasma cells, macrophages, and
B lymphocytes.
Medullary cords
The intervening spaces in
which lymph flows before exiting the node
via efferent lymphatic vessels.
Medullary sinuses
It responds to
antigens that enter the body through mucosae.
MUCOSA-ASSOCIATED LYMPHOID TISSUE(MALT)
Where does the MALT underly
Digestive and respiratory systems
What are the examples of MALT
Tonsils
Lymphoid aggregates (nodules)
Dispersed immune cells
It is found in the underlying connective tissue
surrounding the upper part of the pharynx.
Tonsils
It covers the numerous nodules that compromise the
palatine tonsil.
Stratified Squamous Non-Keratinized Epithelium
Spherical aggregations of lymphocytes that usually
have germinal centers.
Nodules
Infoldings of the epithelium into the underlying
connective tissue.
Crypts
It is large numbers of plasma cells are usually seen in
the underlying connective tissue near the
epithelium.
Plasma cells
The largest secondary lymphoid organ in the body
Spleen
What are the two compartments of the spleen
Red pulp
White pulp
It filters the blood of foreign material
and old or damaged red blood cells
Red Pulp
The site of immune reactions to bloodborne
antigens
White pulp
The spleen is also the storage site of what
RBC, platelets and iron
It is the dense connective tissue enclosing the organ.
Capsule
A connective tissue that extends inward from the capsule through which
blood vessels enter the pulp.
Trabecula
It appears basophilic due to the large number of
nuclei.
White pulp
Clusters of B lymphocytes
located on central arterioles. They usually
contain a germinal center of activated B lymphocytes.
Splenic nodules
Branches of trabecular
arteries coated by PALS and adjacent to
nodules.
Central Arterioles
cylindrical mass of
mature T lymphocytes that
surrounds central arterioles.
PERIARTERIOLAR LYMPHATIC SHEATH (PAL)
It filters and degrades red blood cells (RBCs)
Red pulp
The region between white and red pulp where
macrophages, dendritic cells, and lymphocytes
interact.
Marginal zone
The primary lymphoid organ in which T lymphocytes
proliferate and mature before distribution to
peripheral lymphoid tissues.
Thymus
Is well-developed and fully
functional.
Neonatal Thymus
Thin connective tissue layer surrounding the thymus
that extends inwards to form incomplete lobules.
Capsule
The outer darker, region of small lymphocytes.
Cortex
A small nuclei of condensed
chromatin.
T lymphocytes
Cells with
oval nuclei and lightly stained cytoplasm
with processes.
Epithelial reticular cells
Large cells that
phagocytize T cells marked for removal.
Macrophages
The inner, lighter region of larger lymphocytes.
Medulla
Closely packed, concentrically arranged epithelial reticular cells
Hassell’s Corpuscle
it is the most readily identifiable feature of the thymus.
Hassell’s Corpuscle
