Immune system

Histophysiology

Innate Immunity

The innate immunity system is what we are born with

It is nonspecific

All antigens are attacked equally.

It is genetically based

We pass it on to our offspring.

Surface Barriers or Mucosal Immunity1.The first the most important barrier is the skin and mucosa. 2. Secretion on surface of skin and mucosa3. Epithelial barrier4. Macrophages, mast cells5. Blood cells: platelets, Nph, Eo, NK

Cells mediating immunity

Antigen presenting cells

Antigen processing and presentation

Diversity of dendritic cells

Organs of immune system

Central organs:

-Red bone marrow

- Thymus

Peripheral

-Spleen

- Lymph nodes

- MALT

Red bone marrow

Myeloid tissue-Hematopoietic cells-Microenvironment

Key morphological features

1. Sinusoidal capillaries

2. Megakaryocytes

3. Adipocytes

4. Many immature and

maturing cells

Cells maturation and kinetics in RBM

Thymus

1. Type of structure is parenchymal lobulated

2. Parenchyme is lymphoid tissue.

3. Each lobule consists of cortex and medulla.

4. In medulla there are Hassal`s bodies

Selection of lymphocytes in thymus

Types of T-lymphocytes

Regulatory T cells: friend or foe in immunity to infection?

Spleen

1. Type of structure is parenchymal

2. Stroma is composed by capsule and trabecules (DCT +SM + ElF)

3. Parenchyme includes red and white pulp.

3. White pulp is lymphoid tissue, forms LSh and LF.

4. Red pulp includes sinusoids and cords.

Spleen

Spleen

Lymph nodes

Lymph node

1. Type of structure is parenchymal

2. Stroma is composed by capsule and trabecules (DCT)

3. Parenchyme includes cortex and medulla.

4. Cortex includes LFs and paracortical zone.

5. Medulla includes sinuses and medullary cords.

Lymph node

Funny humoral immunity