Lymphoid Structures

Question 1

Primary Organs

Answer 1

Bone marrow—immune cell production, B cell maturation

Thymus—T cell maturation

Question 2

Secondary Organs

Answer 2

Spleen, lymph nodes, tonsils, Peyer patches ƒ

Allow immune cells to interact with antigen

Question 3

Lymph node

Answer 3

Follicle:
Site of B-cell localization and proliferation

Medulla:
Consists of medullary cords (closely packed lymphocytes and plasma cells) and medullary sinuses

Paracortex:
Houses T cells.

Question 4

Spleen

Answer 4

located in LUQ

White pulp: B cells, T cells

Marginal Zone: macrophages, specialized B cells, APCs

Question 5

Splenic macrophages remove

Answer 5

encapsulated bacteria.

Question 6

Splenic Dysfunction

Answer 6

decreased IgM ->
decreased complement activation ->
decreased C3b opsonization ->
increased susceptibility to encapsulated organisms

Question 7

Thymus

Answer 7

Site of T-cell differentiation and maturation

Encapsulated

derived from Third pharyngeal pouch

Question 8

Normal neonatal thymus shape

Answer 8

“sail-shaped” on CXR

involutes with age

Question 9

Thymoma

Answer 9

neoplasm of thymus.

Associated with myasthenia gravis and superior vena cava syndrome.