Bhl Week 4: Organs Of The Immune System

Front 1

What is the morphological sign on a blood smear of lack of splenic function?

Back 1

Howell-Jolly bodies
(small nuclear fragments left behind when RBCs lose their nucleus)

Front 2

How does most of the blood in the spleen drain? (Closed or open circulation)

Back 2

Closed circulation
(venous sinusoids)

Front 3

How is the open circulation in the spleen composed?

What is the function of open circulation?

Back 3

Open splenic cords

*Macrophages line the splenic cords and screen/phagocytize RBCs

Front 4

What does the red pulp consist of?

Back 4

Splenic cords and venous sinusoids

Front 5

The trabecular artery gives rise to which arteries?

Back 5

Central arteries

Front 6

What surrounds the central arteries in the spleen?

Back 6

Sheath of lymphocytes
(Periarteriolar lymphoid sheath-- predominantly T-cells)

Front 7

What makes up the white pulp in the spleen?

Back 7

1. Periarteriolar lymphoid sheath
2. Follicles

Front 8

What are the functions of the spleen?

Back 8

1. Protection against blood borne pathogens
2. Antibody production
3. Screens/eliminates senescent or defective RBCs
4. Stores platelets and some granulocytes

Front 9

What is the result of hypersplenism?

Back 9

Splenic enlargement w/ sequestration of WBCs, RBCs, and platelets

Front 10

What is the result of hyposplenism?

Back 10

Increased risk of severe bacterial sepsis

Front 11

List 4 causes of splenomegaly

Back 11

1. Congestive splenomegaly
2. Reactive splenomegaly
3. Infiltrative diseases
4. Malignancies

Front 12

What causes congestive splenomegaly?

Back 12

1. Cirrhosis of the liver
2. Right heart failure
3. Thrombosis of portal or splenic viens
4. Chronic hemolytic anemias

Front 13

How are gastroesophageal varices formed?

Back 13

Backup of blood from portal V through splenic V to gastric VV.

Front 14

Which syndrome is a triad of RA, splenomegaly, and neutropenia?

Back 14

Felty syndrome

*Can result in reactive splenomegaly

Front 15

List 3 causes of reactive splenomegaly.

Back 15

1. Infections of any type
2. Chronic inflammatory disorders
3. Hemolytic anemias

Front 16

There are 3 hematologic neoplasms which are commonly associated with marked splenomegaly. List these 3 neoplasms.

Back 16

1. CML
2. Primary myelofibrosis
3. Hairy cell leukemia

Front 17

The thymus is a derivative of which embryological structure?

Back 17

3rd pharyngeal pouches +/- 4th pouches

Front 18

What is the thymus predominantly composed of?

Back 18

Epithelial cells and immature T-cells

Front 19

Where are Hassall's corpuscles located?

Back 19

Medulla of the thymus
(islands of squamous cells)

Front 20

Where are most immature T-cells located in the thymus?

Back 20

Superficial cortex
(move to the medulla as they mature)

Front 21

Which congenital syndrome results in thymus aplasia or hypoplasia?

Back 21

DiGeorge Syndrome

*Related to abnormalities of the 3rd and 4th pharyngeal pouches

Front 22

What is the result of DiGeorge syndrome on the thymus and parathyroid glands?

Back 22

Absent or hypoplastic thymus --> IMMUNODEFICIENCY

Aplasia/hypoplasia of parathyroid glands --> hypoparathyroidism --> HYPOCALCEMIA

Front 23

How is DiGeorge Syndrome confirmed?

Back 23

FISH, looking for deletion of chromosome 22q11.2

Front 24

What is the mode of inheritance of Wiskott-Aldrich syndrome?

Back 24

X-linked recessive

Front 25

What is the mode of inheritance of Ataxia-Telangiectasia?

Back 25

Autosomal recessive inheritance

Front 26

Wiskott-Aldrich syndrome involves abnormalities of a gene producing which protein?

Back 26

WAS protein

Front 27

Ataxia-Telangiectasia involves the mutation of which gene?

Back 27

ATM gene

Front 28

List 3 syndromes that result in thymus aplasia or hypoplasia.

Back 28

1. DiGeorge syndrome
2. Wiskott-Aldrich syndrome
3. Ataxia-Telangiectasia syndrome

Front 29

Which syndrome results in cerebellar ataxia and immunodeficiency?

Back 29

Ataxia-Telangiectasia

Front 30

Which syndrome characteristically results in thrombocytopenia with small platelets?

Back 30

Wiskott-Aldrich syndrome

Front 31

Thymic follicular hyperplasia is often associated with which diseases?

Back 31

Autoimmune diseases-- espeically myasthenia gravis

Front 32

How is Thymic follicular hyperplasia diagnosed?

Back 32

Presence of lymphoid follicles in the thymus

Front 33

What is the most common tumor of the thymus?

Back 33

Thymomas
(tumors of thymic epithelial cells)

Front 34

List 2 hematologic neoplasms that may affect the thymus.

Back 34

1. T-lymphoblastic leukemia/lymphoma
2. B-cell lymphomas

Front 35

List 3 types of thymomas.
Which is the most common?

Back 35

1. Encapsulated <---MOST COMMON
2. Invasive, but cytologically benign
3. Thymic carcinomas <--Most rare

Front 36

What is the prognosis of encapsulated thymomas?

Back 36

Very good

Front 37

Which variant of thymoma has the worse prognosis?

Back 37

Thymic carcinoma

Front 38

Thymomas are often associated with which disease?

Which other disease are sometimes associated with it?

Back 38

Myasthenia gravis

Others:
1. Grave's disease
2. Pure red cell aplasia

Front 39

What is the most common hematologic neoplasm of the thymus?

How does it typically present?

Back 39

T-lymphoblastic leukemia/lymphoma

*Present with large mediastinal mass

Front 40

T-lymphoblastic leukemia/lymphoma is most common in which individuals?

Back 40

Adolescent males

Front 41

Do the majority of T-lymphoblastic leukemia/lymphomas present as lymphomas or leukemias?

Back 41

Lymphomas
(tissue mass w/o blood or bone marrow involvement)

Front 42

Which neoplasm is derived from thymic B-cells?

This neoplasm typically occurs in what type of individuals?

Back 42

Primary Mediastinal Large B-Cell Lymphoma

*Young women

Front 43

Extranodal lymphoid tissue is important in the production of which immunoglobulin?

Back 43

IgA

Front 44

Which drug often causes lymphadenopathy?

Back 44

Phenytoin

Front 45

List the arterial branches which stem from the Splenic artery?

Back 45

Splenic A --> trabecular AA --> Central AA --> Penicilliary AA