Md1 Histology Block 3 Lymph System 3

Front 1

Lymph nodes how many ovoid

Back 1

(400 – 450) are ovoid encapsulated

Front 2

Lymph nodes describe =

Back 2

They lie in series
Sites rich in nodes
root of the limbs, the neck, retroperitoneum and mediastinum.

Front 3

Lymph nodes
The function of lymph nodes is to

Back 3

filter the lymph,
maintain and produce B cells,
house T cells.

Front 4

Lymph node

is surrounded by a

Back 4

capsule
parenchyma is divided into a cortex and a
medulla.

Front 5

___________ vessels (entering the node) pass through the convex surface of the capsule to open into the subcapsular lymph sinus.

Back 5

Afferent lymphatic

dense collagenous
indentation called hilum.
Trabeculae project from the inner surface into the node.

Front 6

Lymph node cortex

Back 6

loose lymphoid tissue
subcapsular sinuses.
reticular cells and fibers.
antigens
APCs
diffuse population of cells composed mainly of T lymphocytes and reticular cells macrophages and APCs are also present in this area.

Front 7

Follicular dendritic cells

Back 7

branched cells forming a network within the lymphoid follicle.

Front 8

medulla contains two major components

Back 8

Medullary sinusoids
lined by endothelial cells surrounded by reticular cells and macrophages.


Medullary cords
with B cells,
macrophages
plasma cells.

Front 9

Afferent lymphatic

Back 9

lymphatic vessels carrying lymph from connective tissue spaces or other lymph nodes pierce the capsule and empty in large subcapsular sinus which lies directly beneath the capsule.

From the subcapsular sinus ly

Front 10

cortical sinuses

Back 10

From the subcapsular sinus lymph enters the cortex to pass through cortical sinuses and enters medullary sinuses which are continuous with the cortical sinuses.

Front 11

Medullary sinuses

Back 11

converge toward the hilus to drain in efferent lymphatic vessels.

Front 12

. Recirculation of lymphocytes

Back 12

Recirculating T or B lymphocytes may enter a node through its arterial vessels --- pass through capillaries --- to reach post capillary venules then pass through their walls into the parenchyma of the node.

Front 13

acute lymphadenitis ***

Back 13

When the immune reaction is acute in response to locally drained bacteria (for example, infections of the teeth or tonsils), local lymph nodes enlarge and become painful because of the distention of the capsule by cellular proliferation and edema. This condition is known as acute lymphadenitis.