Functional Anatomy of Lymphoid Tissue

Question 1

T Cells

Answer 1

Recognize processed antigens and MHC

responsible for the cellular immune response

Question 2

B Cells

Answer 2

recognize conformation epitopes on while proteins and make anti-bodies
responsible for the HUMORAL Immune Response

Question 3

Lymphatic Tissues are where lymphocytes

Answer 3

proliferate
differentiate
mature

Question 4

Three lymphoid tissues

Answer 4

primary lymphoid
secondary lymphoid
tertiary lymphoid (develops after birth)

Question 5

Anatomy of the thymus

Answer 5

multi-lobed nodular organ located posterior to the sternum
populated by stem cells from the bone marrow
maximum size at puberty and then undergoes involution

Question 6

Structure that is unique to thymus

Answer 6

Hassal’s Corpuscles

Question 7

Function of Thymus

Answer 7

Alpha beta T cells are “educated” in the thymus

i.e. positive and negative selection

Question 8

T Regs express

Answer 8

FOXP3 and INF-Betta

Question 9

Where do mature lymphocytes interact with other immune cells?

Answer 9

In secondary lymphoid tissues

i.e. spleen and peripheral lymph nodes

Question 10

Anatomy of Lymph Node

Answer 10

Cortex: holds B Cells in follicles, T cells everywhere else
Medulla: labyrinth of lymph draining sinuses which contain many plasma cells and macrophages which are attached to reticular fibers

Question 11

How do lymphocytes leave the primary lymphatic node?

Answer 11

Post capillary venules near the germinal centers
From the medulla to efferent lymph

To exit they must down regulate their sphingosine-1-phosphate receptor (S1P Receptor)

Question 12

Anatomy / Function of the spleen

Answer 12

Filter the blood and recycle iron
Capture and destroy pathogens and trigger adaptive immune system
Spleen has NO HEV and NO AFFERENT LYMPHATICS

Question 13

3 Zones of spleen

Answer 13

1. Red pulp: loose tissue between venules
2. White pulp: B and T cell compartments
   T cell surround arterioles
3. Perifollicular zone: surrounds the B and T cell zones

Question 14

Which organ is important for systemic infection?

Which organ is important for localized infection?

Answer 14

Systemic infection relies on the spleen

Localized infection relies on peripheral lymph nodes

Question 15

Tertiary Lymphoid Tissues

Answer 15

MALT
GALT
NALT
BALT - only found in children
Not capsulated
Contain HEV