Download Immune Worksheet Key Session 26

Immune System
Session 26 (KEY)
Leader: Ivy
Course: AnS 214
Instructor: Keating
Supplemental Instruction
Date: 4/5/11
Iowa State University
IMMUNE DEFENSES:
1) Fill in the diagram below with the specific defenses involved with the immune system’s
intrinsic lines of defense:
Innate Defenses
Adaptive Defenses


Surface Barriers
Skin
Mucous membranes



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Internal Defenses
Phagocytes
NK cells
Inflammation
Antimicrobial proteins
Fever

Humoral Immunity
B cells

Cellular Immunity
T cells
2) Which of the innate defenses is the most important mechanism? Inflammation
PHAGOCYTOSIS:
1) Using the diagram to the right, list the steps of
phagocytosis:
Step 1: Phagocyte adheres to pathogen; Forms
pseudopods that engulfs particles
Step 2: Formation of a phagosome
Step 3: Lysosome fuses with the phagocytic
vesicle, forming a phagolysosome
Step 4: Lysosomal enzymes digest the particles,
leaving a residual body
2) What occurs after step 4 represented in the
diagram? Exocytosis of the vesicle removes
indigestible and residual material
3) What aids the adherence of the phagocyte to a
pathogen? Opsonization- coating of pathogen
by complement proteins or antibodies
1
2
3
4
PHAGOCYTE MOBILIZATION:
1) Name and describe the four steps for phagocyte mobilization (how does the phagocyte reach
the pathogen in the first place?):
Step 1: Leukocytosis: Neutrophils enter blood from bone marrow
Step 2: Margination: Neutrophils cling to the capillary wall
Step 3: Diapedesis: Neutrophils flatten and squeeze out of capillaries
Step 4: Chemotaxis: Neutrophils follow chemical trail
OTHER INNATE RESPONSES:
1) What are the specific responses or actions taken by the following immune cells?
Natural Killer Cells: target cells without “self” cell-surface receptors
Eosinophils: target allergens, parasites
Basophils: release histamine, heparin (inflammation)
Mast Cells: induce inflammation
Dendritic Cells: antigen-presenting cell (APC)
2) What are the 3 purposes for the inflammatory response?
 Prevents the spread of damaging agents
 Disposes of cell debris and pathogens
 Sets the stage for repair
3) What are the 5 cardinal signs of acute inflammation? Redness, heat, swelling, pain,
impairment of function
4) What aids the initiation of the inflammatory response? Toll-like receptors (TLR’s)- trigger
release of cytokines
INTERFERONS:
1) What is the main way that interferons
hinder pathogen activity? Hinders
reproduction
2) Using the diagram to the right, indicate
what occurs to activate an interferon and
the response it invokes:
Step 1: Virus enters cell
Step 2: Interferon genes switch on
Step 3: Cell produces interferon
molecules
Step 4: Interferon molecules bind to
neighboring cell
Step 5: Interferon stimulates cell to turn
on genes for antiviral proteins; Antiviral
proteins block viral reproduction
3) What cells in the body produce these interferons? Lymphocytes, WBC’s, Fibroblasts