Immune System

Front 1

Peyer's Patches

Back 1

cluster of lymphatic nodules located in the ileum
GALT

Front 2

Thymus

Back 2

-cortex (dark)
-medulla (light)- mature T cells
-Hassall's corpuscle
-Capsule- incomplete lobules
-no lymphoid nodules
-T cell proliferation and blood-thymus barrier

Front 3

The site of t cell proliferation and the blood-thymus barrier?

Back 3

The cortex of the thymus

Front 4

Thymocytes in the thymus are supported by?

Back 4

meshwork of epithelial reticular cell processes
-no reticular fibers!
-6 types
-desmosomes
-tonofilaments
-form part of blood-thymus barrier
-nurse cells

Front 5

The thymus is developed from?

Back 5

1. endoderm (medullary epithelial reticular cells)
2. ectoderm (cortical epithelial reticular cells)
3.mesoderm (thymocytes, CT capsule

Front 6

Hassall's Corpuscles

Back 6

-thymic medulla
-concentric layers of flattened epithelial reticular cells
-center may be keratinized
-increase with age

Front 7

Blood-thymus barrier

Back 7

-prevents antigenic material from reaching developing T lymphocytes
3 layers:
1. continuous capillaries
2. Macrophages
3. epithelial reticular cells

Front 8

Functions of the lymph nodes

Back 8

filter lymph, maintain and produce T and B lymphocytes

Front 9

Composition of lymph nodes

Back 9

1. cortex (superficial and deep)
2. medulla
3. lymphatic vessels
4. sinuses
5. capsules that extend as trabeculae
6. stroma- rich in reticular fibers

Front 10

Surfaces of lymph nodes

Back 10

convex surface- receives afferent lymphatic vessels

concave surface- (hilum)arterioles enter, efferent lymphatic and venous exit

Front 11

Superficial cortex of the lymph node

Back 11

beneath CT capsule
-subcapsular sinus is between the superficial cortex and the capsule
contains lymphoid nodules (mostly B)
-some have secondary centers

Front 12

Sinuses in lymph nodes

Back 12

are not clear open vessels
-contain reticular fibers, reticular cells, and macrophages
-where lymph filtration occurs
-phagocytosed by macrophages

Front 13

Deep Cortex (paracortical center)

Back 13

-T-cells
-high-endothelial postcapillary venules
-some T lymphocytes enter lymph node by passing through high endothelial cells lining the postcapillary venules

Front 14

Medulla of the lymph node

mostly B cells

Back 14

-lies deep to the paracortex and superficial cortex
-medullary cords, separated by medullary sinuses

Front 15

Medullary cords and sinuses contain?

Back 15

1. reticular cells and fibers
2. macrophages
3. dendritic cells
4. plasma cells and lymphocytes
B lymphocytes predominate in the medulla

Front 16

Functions of lymph nodes

Back 16

1. filtration of lymph
-macrophages and dendritic cells function as Ag presenting cells
2. Lymphocyte production
3. Immunoglobulin production

Front 17

Composition of Spleen?

How does the spleen differ from the thymus and lymph nodes?

Back 17

white pulp- lymphoid nodules
red pulp- erythrocyte-rich tissue
CT capsule
reticular fibers

it lacks a cortex and medulla

Front 18

Marginal zone

Back 18

In the spleen, located between the white pulp and red pulp, along the border of nodule

Front 19

Periarterial Lymphatic Sheaths
(PALS)

Back 19

accumulations of T lymphocytes surrounding each central artery

Front 20

Red pulp

Back 20

in the spleen
-composed of blood sinusoids and splenic cords