Chapter 50

Question 1

Innate immunity

Answer 1

First line of defense. Recognizes specific molecules characteristic of group of pathogens, characterized by rapid response that brings cell to site of infection and uses soluble antimicrobial proteins to fight pathogen.

2 major classes: defensins and interferons

Also leads to activation of inflammatory response and complement pathway

Question 2

Adaptive immunity

Answer 2

highly specific response activated by cells and signals from innate system. Slower, but provides more rapid response to subsequent infections. Carried out by lymphocytes

Question 3

Defensins

Answer 3

Peptides that bind to outer membrane of bacteria to enhance phagocytosis

Question 4

Interferons

Answer 4

Type 1: induce degradation of RNA and block protein production in viral-infected cells
Type 2: produced by T lymphocytes and natural killer cells, defense against infection and cancer

Question 5

Complement

Answer 5

30 different proteins that circulate in blood in inactive form. When activated, proteins aggregate to form membrane attack complex (MAC) that inserts into surface of pathogen, forming pore. Pathogen bursts from extracellular fluid entering pore

Other proteins coat pathogens and signal phagocytosis to neutrophils and macrophage

Others stimulate release of mast cells and basophils, promote capillary dilation and permeability

Question 6

Inflammatory response

Answer 6

Injured cells release chemical alarms, causes nearby blood vessels to dilate and increase permeability, promotes phagocyte accumulation

Question 7

Marcophages

Answer 7

Kill microorganisms through phagocytosis

Question 8

Neutrophils

Answer 8

Produce defensin peptides, most abundant circulating leukocyte. Also use phagocytosis

Question 9

Antigens

Answer 9

Molecule that provokes specific immune response

Question 10

Characteristics of adaptive immunity

Answer 10

1. specificity of recognition of antigen
2. wide diversity of antigens can be specifically recognized
3. memory, immune system responds more quickly to antigen it encountered previously than one its meeting for 1st time
4. ability to distinguish self-antigens from nonself

Question 11

Lymphocytes

Answer 11

leukocytes with surface receptors for specific epitopes on an antigen, directs immune response against either antigen or cell that carrier it.

When naive lymphocyte binds to specific antigen for first time, gets activated by clonal selection (produces clone of cells, some respond immediately while others are memory cells)

Question 12

Antibodies

Answer 12

Highly specific to target antigen/pathogen, bind to antigens and work with macrophages to destruct antigen upon binding

Question 13

Phagocytosis

Answer 13

cell engulfs particle and digests it