Organs of the Immune System Flashcards
Describe the progression of organs or tissues involved in the production of lymphoid cells.
Yolk sac, Fetal omentum, Liver, Spleen, then Bone marrow
A _________ lymphoid organ is associated with the proliferation and differentiation of lymphocytes.
Secondary
A _________ lymphoid organ is associated with the production and maturation of lymphocytes.
Primary
What organs would be considered primary lymphatic organs in rabbits, poultry, dogs, ruminants, and swine?
Cloacal bursa aka Bursa of Fabricius
Bone marrow
Thymus
Peyer’s Patches
What organs would be considered secondary lymphatic organs in horses and cats?
Spleen
Lymph nodes
MALT
Peyer’s Patches
Where does T lymphocyte maturation occur?
The thymus gland
What occurs to the thymus gland as age increases?
It involutes, or decreases in size
Where do B lymphocytes develop and mature?
Cloacal bursa aka Bursa of Fabricius, bone marrow, peyer’s patches (dogs, rabbits, ruminants, swine)
Where are B and T lymphocytes produced?
The bone marrow
T/F: Lymph nodes, the thymus gland, and the spleen have capsules.
True
In the thymus gland, where would lymphocytes be located?
In the cortex
In the thymus gland, where would a decreasingly small number of thymocytes be located?
In the medulla
What tests do maturing T lymphocytes undergo in the thymus gland? Describe these tests.
Negative selection = must be able to recognize self from non-self and not bind strongly to these receptors
Positive selection = must be able to bind to MHC II/Ag complexes with a moderate affinity
What occurs to T lymphocytes that fail to recognize “non-self” cells and bind to strongly to “self” cells?
They are eliminated via apoptosis
If T cells were not negatively selected, what would result?
Autoimmunity as they would attack “self” cells
If T cells were not positively selected, what would result?
An inability to combat infections as they are unable to recognize extracellular or intracellular antigens
T/F: Depending on the binding affinity of a T cell being positively selected, if they have an increased binding ability to MHC II/Ag complexes they are selected to become CD4+ cells, while those T cells with lower binding affinities are programmed to become CD8+ cells.
False, T cells with a stronger affinity become CD8+ cells, as T cells with a lower affinity become CD4+ cells
T/F: The bursa of fabricius does not involute over time.
False, it does similarly to the thymus gland
The epithelium of the cloacal bursa makes folds that extend into _________ that have a medulla and _____, which contains lymphocytes, macrophages, and __________. This area is the site of both ________ and ________ selection of B cells.
Follicles Cortex Plasma cells Negative Positive
Which of the following is not true of secondary lymphoid tissues?
A) Contain both dendritic cells and monocytes that will differentiate into resident macrophages
B) Surgical removal will impair lymphatic drainage but not immune capability
C) They develop late in fetal life and will enlarge in response to antigenic stimulation
D) Can be either encapsulated on non-encapsulated
A) Contain both dendritic cells and monocytes that will differentiate into resident macrophages
Lymph nodes contain a region that comprises predominantly B lymphocytes called the ________, in structures called germinal centers.
Cortex
Lymph nodes contain a region that comprises extensive amounts of T lymphocytes call the ___________, which are also associated with dendritic cells present here as well for antigen presentation.
Paracortex
Afferent vessels will not contain which of the following? A) Antibodies B) Antigens C) Dendritic cells D) Macrophages
D) Macrophages
Within the spleen what does the following area function to do?
Blood filtering, erythrocyte and PLT storage, and recycling iron
Within the spleen what does the following area function to do?
Site of immune induction
Within the ______ of the intestinal tract, peyer’s patches are closely associated with ________ cells, which are specialized antigen-capturing cells that transport antigens from the lumen to peyer’s patches.
Ileum
Microfold (M)
T/F: Only in both rabbits and rodents, peyer’s patches are located randomly throughout the duodenum and jejunum, but all peyer’s patches undergo involution.
False, they are located in the jejunum and ileum in rodents and rabbits
_____________ lymphoid aggregates that are scattered through mucosal surfaces of the body, but predominantly __________ mucosa, which is both an ________ and ________ site.
Non-encapsulated
Intestinal
Inductive
Effector
Mucosal-associated lymphoid tissue makes up a _____ portion of total lymphoid tissue.
Large, major, etc.
