Innate Host Resistance Vet micro exam 3 Part 3

The complement cascade augments?

the antibacterial activity of antibodies

The complement cascade (3)

•Consists of over 30 blood proteins

•Can also function as chemotaxis signals that recruit phagocytes to their activation site

•Puncture cell membranes causing cell lysis

What are the three major activities of the complement cascade?

•Defending against bacterial infections

•Bridging innate and adaptive immunity

•Disposing of waste

Is the classical complement pathway innate or adaptive?

Adaptive

The classical complement pathway is usually?

Dependent on antigen-antibody interactions

•This is part of acquired immunity and is not as fast as other pathways

The classical complement pathway produces?

Cleavage products that participate in opsonization, chemotaxis, and the membrane attack complex

Is the alternative complement pathway innate or adaptive?

Innate

The alternative complement pathway is involved in?

Nonspecific defenses against intravascular invasion by bacteria/fungi

The alternative complement pathway is dependent on?

Interaction of complement with repetitive structures on pathogens

The alternative complement pathway begins and results in?

•Begins with activation of C3 (complement protein)

•Results in formation of membrane attack complex

Is the lectin complement pathway innate or adaptive?

Innate

What is the lectin complement pathway also called?

Mannose-binding lectin pathway

What does the lectin complement pathway begin with?

Activation of C3 and lectin binding

What is the lectin complement pathway dependent on?

Dependent on interaction of host mannose-binding protein (MBP) with pathogen surfaces

Enhances phagocytosis

What is inflammation?

Nonspecific response to tissue injury

What can cause inflammation?

•Can be caused by pathogen or physical trauma

•Acute inflammation is the immediate response of body to injury or cell death

What are the cardinal signs of inflammation?

•Redness (rubor)

•Warmth (calor)

•Pain (dolor)

•Swelling (tumor)

•Altered function

Do you need to have all the cardinal signs of inflammation?

Not but will usually have most of them

What is the acute inflammatory response?

The release of inflammatory mediators from injured tissue/cells initiates a cascade of events which results in the signs of inflammation

What chemical mediators are involved in the acute inflammatory response and their function?

•Selectins - Cell adhesion molecules on activated capillary endothelial cells

•Integrins - Adhesion receptors on neutrophils

•Chemotaxins - Chemotactic factors released by injured cells

Fever (acute inflammatory response) (4)

•Abnormally elevated body temperature:

•Nearly universal symptom of infection

•Associated with certain allergies, cancers, and other organic illnesses

•If cause is unknown, it’s called a fever of unknown origin

What is fever caused by?

Pyrogens

What are pyrogens?

Substances that reset the hypothalamic thermostat to a higher setting

What are two types of pyrogens?

•Exogenous pyrogens

•Endogenous pyrogens

What are exogenous pyrogens?

Products of infectious agents

What are endogenous pyrogens?

Liberated by monocytes, neutrophils, and macrophages during phagocytosis

Benefits of fever (4)

•Inhibits multiplication of temperature-sensitive microorganisms

•Impedes nutrition of bacteria by reducing the availability of iron

•Increase metabolism and stimulates immune reactions and naturally protective physiological processes

•Speeds up hematopoiesis, phagocytosis, and specific immune reactions