Clinical Anatomy and Physiology for Veterinary Technicians

Diapedesis

The process by which white blood cells leave capillaries and enter tissue by squeezing through the tiny spaces between the capillary cells. (chapter 13)

Macrophages

Phagocytic cells that can engulf relatively large cells or bits of debris. They may be fixed in place, or they may travel around in the tissues. Mature macrophages may be become more mobile during times of infection and inflammation. (chapter 13)

Phagocytosis

Ingestion of microorganisms or other substances by phagocytic cells (neutrophils, monocytes, and macrophages). (chapter 13)

Antigens

Cells or organisms that are "not self". An antigen also can be a structure on a cell membrane that the body recognizes are foreign. The presence of an antigen initiates an immune response in a healthy animal. (chapter 13)

Epitope

The part of an antigen molecule to which an antibody attaches itself. (chapter 13)

Antobodies

Proteins produced by plasma cells (transformed B lymphocytes) in response to the presence of an antigen. A specific serum antibody is generated for a specific antigen. (chapter 13)

Immunoglobins

Created by B lymphocytes; also called antibodies; these protein-based molecules are produced by exposure to an infectious agent's antigen. In future encounters with the same antigen, the antibodies will identify and fight it. (chapter 13).

Lymphatic System

The network of vessels through which lymph drains from the tissues into the blood. (chapter 13)

Edema

An abnormal accumulation of fluid, either localized or generalized, within the tissues or cavities of the body. (chapter 13)

Immune System

A network of cell types working together to defend and protect the body from "invaders" such as viruses, infections and disease. (chapter 13)

Innate (non-specific) immune system

The defense system with which you were born. It protects you against all antigens. Innate immunity involves barriers that keep harmful materials from entering your body. These barriers form the first line of defense in the immune response. (chapter 13)

Skin

Part of the integumentary system, the body's outer covering, which protects against heat and light, injury, and infection (chapter 13)

Mucous Membranes

The mucus-producing layer of stratified squamous or columnar epithelium found over the lamina propria. It is present in organs that have contact with the outside of the body. Mucus production in mucous membranes is commonly found in the digestive, respiratory, and reproductive tracts, with the exception only of the urinary tract. The mucus secreted in them helps fight infection because it is loaded with antibodies. Mucus also helps absorb nutrients and lubricate surfaces. (chapter 13)

Inflammation

The first step in the healing process when the body is injured. Its purpose is to "clean up" the damaged area through various inflammatory processes so healing can begin. (chapter 13)

Natural Killer (NK) lymphocytes

Lymphocytes that are neither T lymphocytes nor B lymphocytes but have the ability to kill some types of tumor cell and cells infected with various viruses. (chapter 13)

Interferon

A substance produced by a cell after a virus has invaded it. Interferon prevents further development or spread of the virus. (chapter 13)

Complement

A group of inactive enzymes (proteins) in plasma that can be activated to rupture the cell membrane of a foreign cell. Complement can also act as an opsonin. (chapter 13)

Specific immunity/Adaptive Immunity

Portion of the immune system that is able to target specific antigens. (chapter 13)

Humoral Immunity

A type of defensive immune response regulated by B lymphocytes. When B lymphocytes are activated by the presence of an antigen, they transform into plasma cells that produce antibodies against the antigen. (chapter 13)

Plasma Cells

A type of immune cell that makes large amounts of a specific antibody. Plasma cells develop from B cells that have been activated. A plasma cell is a type of white blood cell. Also called plasmacyte. (chapter 13)

B Lymphocytes

The type of lymphocyte that is responsible for humoral immunity through its transformation into a plasma cell and production of antibodies (chapter 13)

Cell-mediated immune response

Response of the body's cells that regulates the destruction of infectious bacteria and viruses during specific immune responses. (chapter 13)

T Lymphocyte

The type of lymphocyte that is responsible for cell-mediated immunity. (chapter 13)

Natural Killer (NK) Lymphocytes

Lymphocytes that are neither T lymphocytes that are neither T lymphocytes nor B lymphocytes but have the ability to kill some types of tumor and cells infected with various viruses. (chapter 13)

T Lymphocyte

The type of lymphocyte that is responsible for cell-mediated immunity. (chapter 13)

Cytokines

Signaling molecules responsible for cell movement/signaling. (chapter 13)

Suppressor T Cells

Lymphocytes that inhibit helper T cells and cytotoxic T cells by negative feedback. They also prevent B lymphocytes from transforming into plasma cells. These cells provide the means by which the immune response can be shut down. (chapter 13)

Memory Cells

After an initial immune response, lymphocytes that are programmed to remember the antigen that caused the immune response to that antigen the second time the body is exposed to it. (chapter 13)

Immunization

The process of creating immunity within an animal, usually by introducing a killed or modified culture of the infectious agent to the body to allow it to create antibodies; also called vaccination. (chapter 13)

Passive Immunity

The transmission of intact, preformed antibodies from one animal to another. The antibody molecules can help protect the recipient animal from disease-causing agents. (Chapter 13)

Active Immunity

Activation of the immune system by either administration of a vaccine that contains a modified antigen or exposure to the antigen. (chapter 13)