Lecture 14 immune system

Hematopoietic Growth Factors:

Erythropoietin

Colony-stimulating factors (CSF)

some interleukins (IL)

Hematopoietic Growth Factors Functions

regulate differentiation of a hematocytoblastic stem cell into the different types of blood cells.

Erythropoietin (EPO) Secreted by

kidney and astrocytes in

response to hypoxia (low oxygen)

Erythropoietin Function

Stimulates erythrocyte proliferation

Increases hemoglobin content per red blood cell

Promotes early release of erythrocytes from

bone marrow

Immunoinflammatory Factors:

Interleukins

Interferon

tumor necrosis factor

Humoral immune response

Protein molecules or antibodies

produced by the immune system attack bacteria and viruses that

are in fluids of the animal body but outside the cells.

Cellular immune response

Certain cells mount an attack against viruses that have become established within cells of the animal body and against fungi and microscopic animals.

Immunoglobulin (antibody) types

IgM

IgG

IgA

IgE

IgD

Immunological Response Step 1

Response to initial antigen exposure and then to secondary antigen exposure.

Immunological Response Step 2

Class switching (Switching from one type of immunoglobulin to another).

Immunological Response Step 3

Involvement of white blood cells and lymphocytes

Inflammatory Hormones – Eicosanoids

prostaglandins, thromboxanes, leukotrienes, lipoxins

Eicosanoids Actions

mediation of inflammation

prevention of blood loss

smooth muscle contraction

mediation of inflammation

prostaglandins and leukotrienes stimulate dilation of blood vessels to produce erythma (redness of skin), stimulate leakage of blood vessels to produce edema (swelling of tissue do to fluid accumulation), provoke pain and fever, chemotaxis and stimulate lysosome release.

What counteracts inflammation

Lipoxins

prevention of blood loss

thromboxines constrict blood vessels and promote platelet aggregation to facilitate blood clotting