Anatomy and Physiology 2 Pg. 4
The skin is what part of immunity?
The skin is innate immunity.
How does the skin repel many pathogens in many ways? (2)
The skin repel many pathogens in many ways:
1. the highly keratinized cells provide a physical barrier to pathogens.
2. the acidity of sweat can kill some pathogens;
Sebum is _____
Sebum is bactericidal.
Mucous membranes are what type of immunity?
Mucous membranes are part of innate immunity.
What 4 places do mucous membranes line?
Mucous membranes line the:
1. digestive tract
2. respiratory tract
3. reproductive tract
4. urinary tract
All are potential entrance points for pathogens.
What are mucous membranes often covered in?
Mucous membranes are often covered in sticky, pathogen-trapping mucus.
Respiratory mucosa is also what?
Respiratory mucosa is also ciliated.
What do cilia do?
Cilia sweep bacteria-laden mucus upward to the pharynx where it can be swallowed.
What also assists in the expulsion of microbes? (2)
Coughing and sneezing also assists in the expulsion of microbes.
What is another specific way mucous membranes can impair pathogens?
Acidity of certain mucosal secretions (gastric and vaginal) can impair pathogens).
Bacterial competition is part of what type of immunity?
Bacterial competition is part of innate immunity.
How does bacterial competition work and where does it take place?
Growth of disease-causing organisms is inhibited by the normal bacterial flora in the gastrointestinal and urogenital tracts. These bacteria successfully compete with the pathogenic ones for nutrients and resources.
What is the most important cellular component of innate immunity?
WBCs and their derivatives are the most important cellular component of the innate immune system.
Diapedesis is when WBCs can exit blood vessels
Positive chemotaxis definition:
Positive chemotaxis is when WBCs converge upon areas of infection/damage.
What are the 4 WBCs that are involved in innate immunity?
The 4 WBCs that are involved in innate immunity are:
3. Natural killer cells
What WBC is the first to enter infected tissue?
Neutrophils are the first WBC to enter infected tissue.
What are neutrophils?
Neutrophils are small phagocytic cells.
What do neutrophils primarily function as?
Neutrophils primarily function as bacteria killers.
What are macrophages and where are they derived from?
Macrophages are large phagocytic cells that are derived from monocytes.
What are the 2 types of macrophages and what do they do?
The 2 types of macrophages are:
1. Free macrophages - which wonder thru tissue spaces looking for invaders.
2. Fixed macrophages - which are permanent residents of a particular organ.
What do macrophages perform? Describe it.
Macrophages perform phagocytosis - ingesting something (a bacterium, cellular debris, etc.) and enclose it within a membrane-bound vesicle.
How does phagocytosis begin?
What is this process called?
Phagocytosis begins with the adherence of a microbe to the phagocyte. The probability of this occurring increases markedly when antibodies or complement proteins have already bound to the microbe.
This process is known as opsonization.
What happens after opsonization?
After oposonization, the phagocyte extends membrane "arms" that wrap the microbe and engulf it, forming a membrane-bound vesicle containing the pathogen.
A membrane-bound vesicle containing the pathogen is called what?
This cesicle is known as a phagosome.
The phagosome then does what? Which contains what?
The phagosome then will fuse with a lysosome, an organelle that contains digestive enzymes.
What does the enzymes of the lysosome do?
The enzymes of the lysosome will then destroy the engulfed invader, "chopping it up" into pieces.
After the enzyme of the lysosome destroy the invader, what happens to any indigestible material?
Whatever indigestible material remains is released by way of exocytosis.
What is the only lymphocyte that is part of innate immunity?
NK cells are the only lymphocyte that is part of innate immunity. It is not specific to a particular antigen.
What are NK cells and what do they do?
NK cells are specialized lymphocytes that patrol for and attack and destroys virus-infected cells and cancer cells.
Eosinophils have several options in its arsenal what are they? (2)
1. release chemicals that are toxic to parasites in particular.
2. phagocytize pathogens that have been coated with antibodies.
What are the 2 antimicrobial proteins of innate immunity?
The 2 antimicrobial proteins of innate immunity are:
2. complement system
Why did interferons get their name?
Intererons got their name because interferons "interfere" with viruses.
What are interferons?
Interferons are protein chemicals produced by cells that have been infected with a virus.
How do interferons work?
Interferons diffuse to nearby cells and stimulate them to synthesize a protein that prevents viral replication. This prevents copies of the original virus from taking over neighboring cells.
Do interferons save the infected cells?
Interferons don't save the infected cell but they do prevent nearby cells from being infected.
What are interferons considered part of innate immunity?
Interferons are considered part of innate immunity because the same interferons can protect against many different types of viruses (thus not specific).
How did the complement system get its name?
The complement system got its name because they complement the actions of antibodies.
What does the complement system refer to?
The complement system refers to a group of over 30 special plasma proteins synthesized by the liver.
The complement system is normally found where?
The complement system is normally found in the blood in an inactive state.
How may the complement system be activated?
The complement system may be activated by interacting directly with microbes or with antibodies (members of adaptive immunity).