Immune System Lymphatics

What is the job of the Immune system?

Protects the body from foreign particles and cancer cells

What is the general structure of the Immune system?

Parenchyma and Stromal cells

What is another term for Parenchyma?

Immunocytes

What makes up parenchyma

Lymphocytes, Neutrophils, Macrophages

Stromal cells are?

Supporting cells

What makes up stromal cells?

Reticular cells, epithelial cells,dendritic cells

What do reticular cells form?

Form a reticulum in lymphatic organs except thymus and cloacal bursa.

Do epithelial reticular cells produce reticular fibers?

no

What is the function of dendritic cells?

Capture and present antigens to lymphocytes and form stroma of lymphatic tissue

How many types of dendritic cells are there?

4

what is the job of Follicular dendritic cell?

Present antigen to B lymphocyte in lymphatic organs

What do interdigitating dendritic cells do?

Present antigen to L lymphocyte in lymphatic organs

What is another term for intraepidermal macrophage?

Langerhans cell

What do Langerhans cells do

present antigen to T lymphocyte in EPIDERMIS

Where are veiled cells and what do they do?

Blood and Lymph;present antigen to T lymphocyte

What do lymphocytes filter?

Tissue/lymph

What does the spleen filter

blood and blood borne antigens

what surrounds a lymph node?

a capsule of Dense irregular connective tissue

what divides a lymphnode

Trabeculae

how do efferent lymph vessels run in a lymphnode?

Outer cortex and inner medulla

in the pig how are the lymph nodes organized?

Cortical and medullary tissues are reversed

how are stroma and parenchyma arranged in subscapular & medulla

Loosely arranged

How are parenchyma and stroma arranged in the cortex

tightly packed

What is the thymus divided into

lobules

Lobules of thymus have what?

peripheral dark zone (cortex)&central light zone (medulla).

The stroma of the thymus consists of?

f epithelial reticular cell and its processes

Where does blood leave and enter a lymphnode?

Post capillary venule

What does medulla of thymus contain?

Hassall’s corpuscles

What are Hassall’s corpsucles

flattened degenerated epithelial reticular cells

what is a lymphoblast?

A maturing T lymphocyte

What makes up the blood thymic barrier

capillary endothelium, perivascular space, and a sheath of epithelial reticular cell process.

The blood thymic barrier protects?

Lymphoblasts

Does the thymus have afferent lymphatic vessels?

no

What happens to the thymus @ around 6 months

Regresses

stroma of thymus is made up of

Epithelial reticular cells and processes NO FIBER

What is the capsule of the spleen made of?

Smooth muscle

Which species has muscular capsule and trabeculae in the spleen?

Carnivores

Where does erthyropoisesus in fetus occur

Bone marrow-spleen

What is the red pulp composed of

splenic cords and splenic/ venous sinuses

White pulp is composed of

Peri-aterial Lymphatic Sheath (PALS)

What are splenic cords enmeshed with

Erythrocytes

The periphery of white pulp is bounded by what

Circumferential reticular network w/ B cells and macrophages

What are sheathed capillary/ellipsoids

Capillaries surrounded by macrophages

Marginal zone plays a key role in what

Filtration of blood

The spleen of which species are abundant in lymphatic nodules

Dogs horses and pigs

Which 2 species have less abundant lymphatic tissue

Cats and ruminants

Tonsils lie where

Beneath or in contact with pharyngeal epithelium

The tonsils are made up of

Stratified squamous (oropharynx) or pseudostratified (nasopharynx) epithelium.

Peyers patch are present for

maturation of B lymphocytes

What species has hemal nodes

Ruminants

What species has a cloacal bursa

Birds

What forms in a cloacal bursa

Epithelial reticular cells and its processes form stroma where B- lymphocytes mature

What is another name for cloacal bursa

Bursa of fabricius