lymphoid system Flashcards Preview

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Flashcards in lymphoid system Deck (24):
1

classification of lymphoid organs

Encapsulated – LN, thymus & spleen
Partially encapsulated - tonsils
Non-encapsulated – Peyer’s patches


2

composed of non-encapsulated, localized lymphocyte infiltration and lymphoid nodules in the mucosa of the GIT, respiratory & urinary tract.

MALT (mucosa-associated lymphoid tissue)

3

Distribution of lymphoid organs and lymphatic vessels in the body.

Found throughout the body along the course of lymphatic vessels that carry lymph into the thoracic and right lymphatic duct.

lymph nodes

4

lymph nodes location

Located in the mesentery, axilla, groin, along the great vessels of the neck & in the thoraco-abdominal cavities

5

lymph circulation

Afferent lymphatic vessels
Systems of lymph sinuses within the node
Efferent lymph vessels

6

path of lymph circulation

Afferent lymph vessels - marginal sinus -cortical sinus paracortical sinus -medullary sinus-efferent
lymphatic vessels

7

functions of the lymph node

Production of lymphocytes
Production of antibodies
Important role in the phagocytosis of foreign materials

8

lymph node

The only lymph organ located in the course of lymphatic vessels

With both efferent & afferent lymphatic vessels

Only lymph organ with lymph sinuses & filters lymph

9

Dense accumulation of lymphatic tissues in the tunica propria of the oral cavity and pharynx

Partially encapsulated

Lymphoid Ring of Waldeyer

Lymphocyte & anti-body production

tonsils

10

Lined by stratified squamous epithelium

With tonsillar crypts

Salivary corpuscles

palatine tonsils

11

Lined by pseudostrat. ciliated col. epith w/ patches of stratified squamous epithelium

With shallow infoldings (pleats)

Adenoids

pharyngeal tonsils

12

Found in the upper portion of the tongue behind the circumvallate papillae

W/ deep & wide-mouth crypt

Lined with stratified col. epithelium

lingual tonsils

13

Found in the tunica propria of the ileum

Lined by simple col. epithelium w/ striated border


peyer's patches

14

are there villi over peyer's patches?

no

15

With few or absent intestinal glands

Most prominent in children

Affected in TB of the intestines & Typhoid fever

peyer's patches

16

Major lymphatic organ

Located in the anterior mediastinum

Capsulated

Undergoes “age involution”

thymus

17

No germinal centers

Abundant lymphocytes

Few endodermal reticular cells / thymic epithelial reticular cells

cortex

18

Structures separating blood from the cortical tissues

Endothelial cells joined by occluding junction
Basal lamina of the capillary endothelium
Perivascular space
Basal lamina of the epithelial reticular cells
Thymic epithelial reticular cells (epithelial barrier)

19

More epithelial reticular cells

Less lymphocytes

Hassall’s body / thymic corpuscles

medulla

20

functions of hassall's body

Lymphopoiesis

Important role in immune mechanism

* rejection of grafts / transplants
* Myesthenia Gravis

21

Largest lymphoid organ

Found in the course of blood vessels

W/ a fibroelastic capsule with smooth muscles

Distensible

spleen

22

Billroth cord / Pulp cord

Venous sinuses

Atypical type

red pulp

23


receives the incoming arterial blood; first to come into contact with particulate matters and blood borne cells

Marginal zone

24

theories

Open / Slow circulation theory

Closed / Rapid circulation theory

Compromise theory
(combination of open & close theories)

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