Immuno (Lymphoid Structures) Flashcards
What are the primary immune system organs?
1) Bone marrow
2) Thymus
What are the functions of the bone marrow?
1) Immune cell production
2) B-cell maturation
What is the function of the thymus?
T-cell maturation
What are the secondary organs of the immune system?
1) Spleen
2) Lymph nodes
3) Tonsils
4) Peyer patches
What is the function of the secondary immune organs?
Allows immune cells to interact with antigen.
What are the functions of the lymph node?
1) Nonspecific filtration by macrophages
2) Circulation of B and T cells
3) Immune response activation
True or false:
Lymph nodes are unencapsulated and have trabeculae
False; they are encapsulated and have trabeculae
What are the 3 areas of the lymph node?
1) Follicle
2) Medulla
3) Paracortex
The lymph node follicles are the site of:
B-cell localization and proliferation.
Where are the lymph node follicles found?
In the outer cortex.
Primary follicles are _____ (dense and quiescent/active and have pale germinal centers) while secondary follicles are ____ (dense and quiescent/active and have pale germinal centers).
Dense and quiescent; active and have pale germinal centers.
What does the medulla of the lymph node consist of?
Medullary cords and medullary sinuses.
What are medullary cords?
Closely packed lymphocytes and plasma cells.
What do the medullary sinuses communicate with?
Efferent lymphatics.
What do the medullary sinuses contain?
Reticular cells and macrophages.
What does the paracortex contain?
1) T-cells
2) High endothelial venules (HEV) through which B and T cells enter from the blood.
Which lymph node area is not well developed in patients with DiGeorge syndrome?
The paracortex.
Where is the paracortex found?
The region of cortex between follicles and medulla.
Which part of the lymph node enlarges in extreme cellular immune response?
The paracortex.
If a person was infected with EBV (or other viral infections), which area of the lymph node would we expect show hyperplasia?
The paracortex
Which lymph nodes drain the oral cavity?
Submandibular
Which lymph nodes drain the head, neck, and oropharynx?
Deep cervical
Which lymph nodes drain the abdomen and pelvis?
Supraclavicular (Virchow node) and Periumbilical (Sister Mary Joseph node)
Which lymph nodes drain the trachea and esophagus?
Mediastinal
Which lymph nodes drain the lungs?
Hilar
Which lymph nodes drain the upper limbs, breasts, and skin above the umbilicus?
Axillary
Which lymph nodes drain the hands and forearms?
Epitrochlear
Which lymph nodes drain the liver, stomach, spleen, pancreas, and upper duodenum?
Celiac
Which lymph nodes drain the lower duodenum, jejunum, ileum, colon to splenic fixture?
Superior mesenteric
Which lymph nodes drain the colon from the splenic fixture to the upper rectum?
Inferior mesenteric
Which lymph nodes drain the pair of testes, ovaries, kidneys, and fallopian tubes (uterus)?
Para-aortic
Which lymph nodes drain the cervix, superior bladder, and the body of uterus?
External iliac
Which lymph nodes drain the lower rectum to anal canal (above pectinate line), bladder, vagina (middle third), cervix, and prostate?
Internal iliac
Which lymph nodes drain the anal canal (below pectinate line), skin below umbilicus (except the popliteal area), scrotum, and vulva?
Superficial inguinal
Which lymph nodes drain the dorsolateral foot and posterior calf?
Popliteal
Which lymph nodes are associated gastric cancer?
Periumbilical (Sister Mary Joseph node)
Which lymph nodes are associated with malignancy of abdomen and pelvis?
Supraclavicular (Virchow node)
Which lymph nodes are associated with malignancy of the oral cavity?
Submandibular
List 4 pathologies associated with the deep cervical lymph nodes.
1) URTI
2) Infectious mononucleosis
3) Kawasaki disease
4) Malignancy of head, neck, and oropharynx
Which lymph nodes are associated with Pulmonary TB (unilateral hilar), Sarcoidosis (bilateral hilar), Lung cancer, and Granulomatous disease?
Mediastinal and Hilar
List 2 pathologies associated with axillary lymph nodes.
1) Mastitis
2) Metastasis (especially breast cancer)
Which lymph nodes are associated with secondary syphilis?
Epitrochlear
Which lymph nodes are associated with Mesenteric lynphadenitis, inflammatory bowel disease, and celiac disease?
1) Celiac
2) Superior Mesenteric
3) Inferior Mesenteric
What pathology is associated sith the para-aortic lynph nodes?
Metastasis
Which lymph nodes are associated with Sexually transmitted infections and Medial foot/leg cellulitis (superficial inguinal)?
1) Superficial inguinal
2) External iliac
3) Internal iliac
Which lymph nodes are associated with Lateral foot/leg cellulitis?
Popliteal
What drains the right side of the body above the diaphragm? Where does it drain to?
Right lymphatic duct; the junction of the right subclavian and internal jugular vein.
What drains the left side of the body below the diaphragm? Where does it drain to?
Thoracic duct; the junction of the left subclavian and internal jugular veins.
What can cause chylothorax?
Rupture of the thoracic duct
In which quadrant is the spleen located in?
Left upper quadrant of the abdomen
What are the relations of the spleen?
Anterolateral to the left kidney and protected by the 9th-11th ribs.
Splenic dysfunction (as in postsplenectomy or sickle cell disease autosplenectomy) results in what?
Less IgM = less complement activation = less C3b opsonization = more susceptibility to encapsulated organisms.
What are some postsplenectomy findings?
1) Howell-Jolly bodies (nuclear remnants)
2) Target cells
3) Thrombocytosis (loss of sequestration and removal)
4) Lymphocytosis (loss of sequestration)
What precuation should patients undergoinf a splenectomy take?
They should take vaccines against encapsulated organisms (such as pneumococci, Hib, meningococci..)
What are the 3 areas found in the spleen?
1) Periarteriolar lymphatic sheath (PALS)
2) Follicle
3) Marginal zone
What does the Periarteriolar lymphatic sheath contain? Where is it located?
T-cells; within the white pulp
What does the Follicle contain? Where is it located?
B-cells; within the white pulp
What does the Marginal zone contain? It is the site where what happens? Where is it located?
Macrophages and specialized B-cells; it’s the site where antigen-presenting cells (APCs) capture blood-borne antigens for recognition by lymphocytes; located between the red pulp and the white pulp.
Where is the Thymus located?
In the anterosuperior mediastinum.
Is the Thymus encapsulated or unencapsulated?
Encapsulated
The Thymus is the site of what?
The site of T-cell differentiation and maturation.
The thymus epithelium is derived from ____(mesoderm/endoderm), while the thymic lymphocytes are derived from___(mesoderm/endoderm)
Endoderm;mesoderm
Where exactly is the thymus derived from?
The third pharyngeal pouch (endodermal)
Does the cortex have immature or mature T-cells?
It is dense with immature T-cells.
What does the medulla contain?
It is pale with mature T-cells and Hassall corpuscles containing epithelial reticular cells.
What does the thymus look like in a normal neonate on a chest x-ray?
Sail-shaped.
By what age should the thymus involute?
3 years of age.
How does the thumus present on a chest X-ray in some immunodeficiencies (such as SCID or DiGeorge syndrome)?
Absent thymic shadow or hypoplastic thymus.
What is a thymoma?
Neoplasm of the thymus
What is a thymoma associated with?
1) Myasthenia Gravis
2) Superior Vena Cava Syndrome
3) Pure Red Cell Aplasia
4) Good syndrome
