Chapter 11 - Innate immunity

Innate immunity

Defense present at birth

First line of defense

Physical and chemical barrier that are nonspecific

Physical barriers

First line of defense barriers that make up physical attributes

Skin

First barrier, intact

Mucous membrane

Lines openings to outside

Lacrimal apparatus

Produces tears to wash the eye

Saliva

Dilutes the number of bacteria

Small nose hairs

Helps filter air and trap bacteria

Lower respiratory cilia

Move dust and trapped microorganisms down ciliary escalator to keep lungs clear

Epiglottis

Closes during swallowing

Urine

Cleans urethra

Vaginal secretions

Sweeps away microbes

Defecation

Removes waste through the anus

Vomiting

Rids body of harmful substances

Chemical barriers

First line of defense barriers that use chemical reactions to defend the body

Lysozyme

Breaks down gram positive and some gram negative bacteria in tears and saliva

Sebum

Inhibits some pathogens and fungi via the sebaceous glands

Sweat glands

Releases water to sweep away bacteria

Gastric juices

Lowers the pH

Antimicrobial peptides (AMP)

Proteins that act as chemical barriers by destroying a wide range of pathogens

Defensins

One class of mammalian AMPs that insert themselves into the invaders cell membrane

Second Line of Defense

Phagocytosis, inflammation, fever, and antimicrobial proteins

White blood cells

Cells that search for “nonself” invaders

Immunology

The study of all features of the second and third line of defense

Primary lymphoid tissues

INcludes the thymus and the red bone marrow

Secondary lymphoid tissues

Includes the lymph nodes, the spleen, and the MALT

Leukocytes

Another name for white blood cell

Agranulocytes

Lymphocytes (B and T cells) and monocytes

NK Cells

Natural Killer cells, kills viral infected cells and cancer cells

Differential white blood cell count

Rapid and inexpensive test that helps determine a diagnosis

Phagocytosis

The process of a white blood cell engulfing and killing an invader

Neutrophils

Phagocyte that reacts early in an inflammatory response to a bacteria, damaged cells, and other foreign materials

Neutrophilia

A high count of neutrophils, often a common sign of infection

Neutropenia

A low neutrophil account that may be caused by certain viral invaders

Monocytes

Largest white blood cell, which become activated during chronic infections, inflammation, autoimmune disorders and certain cancers

Macrophages

Kind of phagocytes, transformed monocytes when entering tissues

Never Let Monkeys Eat Bananas

Neutrophils

Lymphocytes

Monocytes

Eosinophils

Basophils

Chemotaxis

Phagocytes that migrate to a region of inflammation

Adhesion and ingestion

Stick to foreign cells and engulf the foreign cell into a vacuole called a phagosome

Phagolysosome formation

Phagosome fuses with a lysosome

Destruction

Destructive chemicals are released in the phagolysosome and destroy the foreign cell

Excretion

Undigestible debris are released by exocytosis

Cytokines

Signaling proteins that help cells communicate with each other and initiate and coordinate immune reactions

Proinflammatory cytokines

Cytokines that mediate immune reactions like inflammation and phagocytosis

Vasoactive mediators

Histamine, serotonin, bradykinin

chemokines

Cytokines that act as signaling proteins that attract WBCs and induce chemotaxis

Interleukins

Roles in activating adaptive and innate immune responses and activating production of new blood cells and platelets

Interferons

Gives alarm when pathogens or tumor cells are detected

Complement

Antimicrobial protein that complements immune reactions

Four signs of inflammation

Pain (dolar), redness (rubor), swelling (tumor), and heat (calor)

Initiator

A virus or bacterium that reacts with a complement protein

C3

The first complement protein that starts the reaction

Opsonization

Complement tags an invader so it stands out to the immune system

Pyrexia

Fever

Pyrogens

Reset hypothalamic thermostat

Exogenous pyrogens

Pyrogens that come from outside the body

Endogenous pyrogens

Pyrogens that come from inside the body

Interleukin (IL-1) and tumor necrosis factor (TNF)

Powerful endogenous pyrogens

99.5-101

Temperature of a low grade fever

105

Temperature of a high fever

109

Temperature of a fatal fever