Module 10
Chapter 16 Innate Immunity: Nonspecific Defenses of the Host
The concept of immunity
· Immunity: ability to protect against ______from microbes and their ______
o Aka, ______
· Susceptibility: vulnerability or lack of ______
· Two general mechanisms of immunity
o ______immunity: defenses against ______
o ______immunity: immunity or resistance to a ______
· Adaptive Immunity
o Involve recognition of ______
o ______to respond than innate immunity
o Has ______component
o Involves “______”
· Innate Immunity
o ______present and available
o Does not involve ______of a microbe
o Acts against ______in the ______way
o ______of defense include physical barriers
§ Skin, mucous membranes
o Early warning system to prevent ______
FIRST LINE OF DEFENSE: Skin and mucous membranes
Physical factors
Skin
· Top layer is dead, ______continually
· No space in between skin cells, microbes can’t ______
· ______of skin inhibits most growth
o In ______conditions, skin infections common
· Keratin: protective ______in skin
· Most infections of skin are “______” – below the skin
Mucous membranes
· Inhibit ______of many microbes
· Mucus: slightly ______fluid composed of ______
o ______invading microbes
o Some pathogens can ______in mucus
· Lacrimal apparatus, saliva, urine, secretions
o Continual ______helps wash away microbes
Ciliary Escalator
· Cilia in respiratory tract ______microbes up
· ______and ______speed up process
Defecation and vomiting
· ______microbes
FIRST LINE OF DEFENSE: Chemical Factors
Sebum
· ______substance in skin produced by ______in skin
· Forms ______film over skin
· Contains ______acids the ______growth of some ______
· Lower ______
· Some bacteria can ______sebum ______
Lysozyme
· ______that breaks down cell wall
· Found in ______, tears, ______, and tissue fluids
Low pH
· Skin (______)
· Gastric Juice (______)
· Vaginal Secretions (______)
Normal Microbiota
· Normal microbiota protect via “______”
· Normal microbiota ______with pathogens for ______
SECOND LINE OF DEFENSE
· If microbes ______first layer, ______begins
· Second line of defense to invasion include defensive cells, inflammation, fever, antimicrobial substances
Formed elements in blood
· Formed elements: ______in blood
o Leukocytes: ______(WBC)
· Different WBC, ______
Types of white blood cells
· Neutrophils
o Highly ______against ______
o Active in ______stages of infection
o Can leave bloodstream and move into ______to fight infection
· Basophils
o Release ______, important in ______
· Eosinophils
o Produce toxins against ______, such as helminths
o Can ______, move into tissue
· Dendritic cells
o Destroy microbes by ______
o Activate ______immune response
· Monocytes
o Not phagocytic in ______
o Can move into tissue, mature into “______”
§ Highly phagocytic
· Lymphocytes
o Natural killer (NK) cells
§ Kill ______cells, ______cells
§ Any cell that displays “______” plasma membrane proteins
o T cells, B cells
o Play central role in ______
Diiferential White Blood Cell Count
· ______of each type of ______in a ______sample
· Leukocytosis: increase in ______
o Can double, triple, quadruple
· Leukopenia: ______in WBC count
o Due to impairment of white blood cell ______, ______
· Differential white blood cell count can help ______type of ______or ______
Phagocytosis
· Phago: from Greek, meaning ______
· Cyte: from Greek, meaning ______
· Ingestion of ______or particles by a ______
· ______: cells that perform phagocytosis
o ______, ______, dendritic cells
· During infection, ______and ______migrate to infected area
· ______increase in initial stages of ______infection
· ______dominate in initial stages of bacterial infection
o ______bacteria
· As infection progresses, ______dominate
o Clear up cell ______
· In ______and ______infections, macrophages always dominate
Mechanism of phagocytosis
· Chemotaxis: chemical ______of phagocytes to microbes
o Attracted to microbial products, damaged tissue cells, various chemicals
· Adherence: ______of phagocyte to microbe
· Ingestion: ______of microbe
o Projections called ______
o Microbe internalized in vesicle called ______
· Digestion: ______of microbe
o Phagosome fuses with lysosome ______, destroys microbe
o ______material expelled from cell
Microbial evasion of phagocytosis
· Inhibit ______
· Kill ______
· ______phagocytes
· ______phagosome
· Prevent ______fusion
· Survive inside ______
Inflammation
· ______response to infection
· Characterized by ______, pain, ______,swelling
· Acute inflammation: ______, intense
o Cause of inflammation removed ______
· Chronic inflammation: ______lasting, less intense
o Cause of inflammation ______
· Functions:
o To ______the injurious agent
o To limit the effects on body by ______injurious agent
o ______or replace damaged tissue
Stages of inflammation
Vasodilation and increased permeability of blood vessels
· Vasodilation: ______(increase in diameter) of blood vessels
o Increases ______to area
o Responsible for ______(redness), ______
· Vasodilation also results in increased ______
o Allows ______, chemicals to pass from ______to injured area
o Responsible for ______(swelling)
Phagocyte migration and phagocytosis
· Blood flow eventually brings ______to site of infection
o ______invading microorganisms
· In response to bacteria, neutrophils first, followed by monocytes
· ______often die after killing many cells; contribute to ______
· ______release from ______cells, ______results in vasodilation, permeability
· Blood clots around injury prevents ______
· Localized collection of pus called an ______
Tissue repair
· Replacement of ______or ______cells
· Speed of repair depends on tissue
o Skin heals fast, cardiac (heart) muscle heals slow
Fever
· ______temperature
· ______response to infection
· Most commonly caused by ______, ______infections
· Certain chemicals trigger a “______” of body “thermostat” to a higher body temperature
o LPS ______
· Chill: response to ______body temperature
· Crisis: response to ______body temperature
· Fever is ______up to certain degree
o Helps increase ______production, ______repair
· Complications include:
o ______: rapid heart rate, may compromise weak hearted
o Increased ______
o ______in young children
o Delirium
o Coma
o ______C (______F) = death
Antimicrobial substances
· Complement system: defensive system consisting of ______in blood
· Destroy microbes by:
o ______(______) of bacteria
o Triggering ______
o Helping with ______
Evading complement system
· Some capsules prevent complement ______
· Some gram-negative bacteria can lengthen surface glycolipids to prevent ______
o “______-resistant”
· Some gram-positive cocci release ______that ______complement proteins
Interferons
· ______produced by ______cells that ______with viral ______
· Effective against many different types of viruses
· Protect ______cells by causing them to produce “______” (AVP)
o ______that inhibit ______of viral particles
· Effective for ______
· ______are toxic to heart, liver, kidneys, bone marrow
Antimicrobial peptides
· Newly discovered, may be most important component of ______immunity
· Small ______ 10 – 20 amino acids
· Bind to ______causing cell lysis
· Produced by ______, ______