Biology Chapter 35: The Immune System

Pathogens

Microorganisms that cause disease

Process to immunity

Exposure, colonization, infection, disease, immune response and recovery (or death), immunity

Lymphoctyes

Cells that are part of the specific immune response

Inflammatory cells

Cells that are part of the non-specific immune response

Antigen

A foregin substance that has the capacity to turn on the specific immune response and its products

Central lymphoid organs

Thymus and bone marrow

Peripheral lymphoid organs

lymphatic system, lymph nodules, lymph nodes, spleen, and circulation

Natural defense factors

Skin, mucus membranes, ciliated epithelium, gastric juices, and lactic acid

Natural defense factors

First barrier to a foreign challenge

Nonspecific immunity

An example of innate immunity; includes endocytosis, inflammation, natural killer cells, and patter recognition receptors

Endocytosis

Cell eating; the engulfment of particulate or soluble matter by cells; includes phagocytosis, pinocytosis, and receptor-mediated endocytosis

Phagocytosis

Ingestion of foreign particulate material; includes recognition, movement toward material, ingestion, vesicle formation, lysosomal fusion, intracellular digestion or neutralization, and the elimination of waste

Inflammation

Infiltration of white blood cells into tissue

Inflammation characteristics

Heat, redness, swelling, pain, and loss of function

Process of inflammation

Capillary dilation, rolling leukocytes, adhesion (migration), diapedesis, and chemotoxis

Natural killer cells

Cell cytotoxicity; kill other cells

Pattern recognition receptors

Toll like receptors expressed on phagocytic cells; allows phagocytic cells to identify and kill

Specific immunity

Acquired/adaptive immunity

Naturally acquired immunity

Direct contact with the antigen

Artificially acquired immunity

Immunization (vaccine)

Characteristics of the specific immune response

Specificity, adaptiveness, discrimination, and memory

Specificity

A characteristic of the specific immune response directed against specific foreign material

Adaptiveness

A characteristic of the specific immune response involving the ability to respond to any foreign material

Discrimination

A characteristic of the specific immune response involving the differentiation between self and non-self

Memory

A characteristic of the specific immune response involving learned behavior/recall of previous exposures

Herd immunity

When a large part of the population in an area is immune to a specific disease. thus, the pathogen is more likely to contract an immune individual than a susceptible one, and the disease does not spread

Thymus

Location of maturation of T-cells that function in cell mediated immune responses and immune regulation

Mature T-cell

defined by having T-cell receptor (TCR) for antigens

Tho differentiation into Th1

Promotes cellular immunity mainly through stimulation Tctl

Th0 differentiation into Th2

Promotes humeral immunity mainly by stimulation B-cells to produce antibodies

Bone marrow

Location of B-cell maturation; bursal equivalent tissue

Bursa of Fabricius

Modified piece of intestinal tissue found in birds; location of maturation of b-cells in birds

Mature B-cell

Defined by having immunoglobal/antibody surface receptors

Lymph nodules

allow immune cells/tissues to be in direct contact with the environment

MALT

Mucusal associated lymphoid tissue; part of the lymph nodules. includes BALT, GALT, and UGALT

BALT

Bronchial associated lymphoid tissue

GALT

gut associated lymphoid tissue

UGALT

Urogenital associated lymphoid tissue

lymph node

Nodes of T and B cells located along the lymphatic system

Afferent lymphatics

Where lymph fluid comes in

Efferent lymphatics

Where lymphatic fluid goes out

Spleen

Repository of red blood cells; also filters the blood as it passes through, so foreign material in the blood stream is caught