Immunology - Lymphoid Structures

Question 1

Label structures (A-G) on the lymph node diagram shown.

Answer 1

(A) capsule; (B) subcapsular sinus; (C) capillaries; (D) postcapillary venules; (E) afferent lymphatic; (F) medullary sinus; (G) trabecula

Question 2

Label structures (H-L) on the lymph node diagram shown (note: [K] represents two separate structures).

Answer 2

(H) medullary cords; (I) paracortex (T cells); (J) follicle of cortex (B cells); (K) artery and vein; (L) efferent lymphatic

Question 3

In the diagram, (J) represents a region that is replete with ____ (B/T) cells and is found in the ____ (inner/outer) cortex.

Answer 3

B cells; outer cortex

Question 4

What are the functions of the lymph node?

Answer 4

Filtration of lymph by macrophages; storage and activation of B and T cells; production of antibodies

Question 5

Does a lymph node have more afferent or efferent lymph vessels?

Answer 5

It has many afferent vessels and few efferent vessels

Question 6

Within a lymph node, what is the site of B-cell localization and proliferation?

Answer 6

The follicle

Question 7

In lymph nodes, _____ (primary/secondary) follicles have pale central germinal centers and are active, while _____ (primary/secondary) follicles are dense and dormant.

Answer 7

Secondary; primary

Question 8

Which lymph node area contains cords of closely packed lymphocytes, plasma cells, and sinuses?

Answer 8

The medulla

Question 9

Which lymph node structures communicate with efferent lymphatics and contain reticular cells and macrophages?

Answer 9

Medullary sinuses

Question 10

Which lymph node area houses T cells?

Answer 10

The paracortex, which is located between the follicles and the medulla

Question 11

In lymph nodes, what is the name of the region that contains high endothelial venules through which T and B cells enter the lymph node from the blood?

Answer 11

The paracortex

Question 12

Which part of the lymph node contains B cells?

Answer 12

Follicles, which are located in the outer cortex

Question 13

In which genetic syndrome would a lymph node biopsy show an underdeveloped paracortex?

Answer 13

DiGeorge syndrome, due to thymic aplasia and lack of functional T cells

Question 14

In what part of the lymph node are the follicles (ie, the sites of B cell localization and proliferation) located?

Answer 14

The outer cortex

Question 15

In lymph nodes, what area becomes greatly enlarged during an extreme cellular immune response and contains high endothelial venules?

Answer 15

The paracortex

Question 16

Into which lymph vessel does lymph from the right arm and right half of the head drain? What is the lymph drainage for the rest of the body?

Answer 16

Right lymphatic duct; the rest of the body drains to the thoracic duct

Question 17

What are the primary lymph nodes in the lymphatic drainage of the stomach?

Answer 17

The celiac nodes

Question 18

What are the primary lymph nodes in the lymphatic drainage of the duodenum, jejunum, and sigmoid colon?

Answer 18

The duodenum and jejunum drain to the superior mesenteric lymph nodes; the primary drainage sites for the sigmoid colon are the inferior mesenteric lymph nodes

Question 19

Which lymph nodes serve as the primary lymph drainage site for the lower rectum and anal canal (above the pectinate line)?

Answer 19

Internal iliac

Question 20

What is the primary lymph node drainage site for the scrotum, thigh, and anal canal (below the pectinate line)?

Answer 20

Superficial inguinal nodes

Question 21

Where does lymph from the testes drain?

Answer 21

The superficial and deep plexuses

Question 22

Where does the lymph from the lateral side of the dorsum of the foot drain?

Answer 22

Popliteal lymph nodes

Question 23

In the spleen, what is the name of the long, vascular channels located in the red pulp that contains the fenestrated barrel hoop basement membrane?

Answer 23

The sinusoids

Question 24

In the spleen, what type of cells are found in the periarterial lymphatic sheath and in the red pulp?

Answer 24

T cells

Question 25

In the spleen, what type of cells are found in the follicles within the white pulp?

Answer 25

B cells

Question 26

In a patient with Streptococcus pneumoniae bacteremia, what important immunologic function does the spleen serve?

Answer 26

Macrophages found within the spleen remove encapsulated bacteria from the blood

Question 27

Name three findings seen on peripheral smear in asplenic patients.

Answer 27

Howell-Jolly bodies, target cells, thrombocytosis

Question 28

What is the major consequence of asplenia?

Answer 28

Increased susceptibility to infection by encapsulated organisms

Question 29

Why are asplenic patients more susceptible to encapsulated bacteria?

Answer 29

Asplenic patients have decreased immunoglobulin M secretion, leading to poor complement activation and therefore inhibited phagocytosis

Question 30

In which encapsulated organ do T cells mature?

Answer 30

The thymus

Question 31

From which branchial pouch is the thymus derived?

Answer 31

Third branchial pouch

Question 32

What is the purpose of negative selection of T cells? Positive selection?

Answer 32

Negative selection ensures that T cells are nonreactive to self, and positive selection ensures that T cells are able to recognize major histocompatibility complex molecules

Question 33

In the thymus, the ______ (cortex/medulla) is dense with immature T cells, whereas the ______ (cortex/medulla) is pale with mature T cells and epithelial reticular cells.

Answer 33

Cortex; medulla

Question 34

Identify structures (A-D) in the spleen sinusoid diagram shown.

Answer 34

(A) central arteriole; (B) germinal center; (C) arterial supply; (D) red pulp

Question 35

Identify structures (E-H) in the spleen sinusoid diagram shown.

Answer 35

(E) PALS; (F) marginal zone; (G) venous drainage; (H) white pulp

Question 36

Area (H), along with the PALS, contain numerous ____ (B/T) cells; the follicles within area (H) contain ____ (B/T) cells.

Answer 36

T cells; B cells; area (H) is a section of white pulp

Question 37

Which area (A-H) on the splenic sinusoid diagram shown contains antigen-presenting cells?

Answer 37

Area (F), the marginal zone