Name: A.JENIFA III BSC Zoology

Lymphoid Organs

Power

Point

presentation

DEFINITION:

The organs concerned with The Production of immune cells andimmune reaction are calledlymphoid organs.

Primary lymphoid organs.Secondary lymphoid organs.

2.Types

PRIMARY LYMPHOID ORGANS

Major Of lymphopoiesis*.Prodution centres & Army head Quarters of the immune system.Large at birth and they atrophy with age.

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THYMUS OF MAN

1.Primary Lymphoid Organ.2. Training Centre For The Army Of Lymphocytes.3. It Resembles A Thyme Leaf And Hence The Name.4. Derivative of pharynx.5. Develop from EPITHELIUM.6. Two oval lobes just behind the top of sternum.

THYMUS OF CHICKEN* The bird is made up of 7 lobes.* Thymus is covered by fibrous capsule.* Organized into lobules.* Separated from one another by septa called trabeculae.

Of thymus

Medulla contains more nature cells. Thymus is responsible for. * T cell maturation . * Cell mediaated immunity.

* Graft rejection.

Structure of a lobule Medulla consists of vascular structure, reticular Epithelial cells & scattered lymphocytes.

Functions of thymus T lymphocytes mature in the thymus. It brings about cell mediated immunity. It bring about graft rejection.

Thymectomy

Surgical removal of thymus.Removed from mice soon after birth.Suffered from hunched appearance,

ruffled fur and diarrhoea.

2.BURSA OF FABRICIUS

oPrimary lymphoid organ in birds.oTraining centre for the army of B

lymphocytes.oCells present in yolk sac, liver and bone

marrow.oBursa is a sac- like lymphoepithelial structure.oOuter cortex and an inner medulla.

BONE MARROW

Primary lymphoid organ. Soft tissus located with in the cavities

bones. It is the Army head Quarter.

Red marrow. Yellow marrow. stroma.

Types

1.Red marrow:Medulla ossium rubra.Consists of mainly haematopoietic.Cantains blood vessels and capillaries.

2.Yellow marrow:Medulla ossium flava.Found interior of long bones .Cantains blood vessels and capillaries.

3.Stroma :Provides a haematopoietic micro

environment.Generates colony stimulating factors .Provides iron for RBC.

Bone Marrow BarrierInhibit the immature blood cells from leaving the maroow.

Lymphatic Role Generate lymphatic cells . It is primary lymphoid organ. Back flow of lymphatic fluid into the bone marrow.

Disease of bone marrow Malignancial. Anaemia. Tuberculosis. Leukemia.

Bone Marrow Examinations Bone marrow biopsy. Bone marrow aspiration.

Early humans ate bone marrow of bones left by lions .

Vietnam beef bone marrow is used as soup.Functions of bone Marrow Malignancial.

Anaemia. Tuberculosis. Leukemia.

Bone Marrow Food