Study Guide for Host Immunity
Innate immune system worksheet
What are the general characteristics of the innate immune system? Of the adaptive system?
Innate —> first and second line of defense, nonspecific immunity, physical, chemical, and genetic barriers,
made up of granulocytes (neutrophils, eosinophils, basophils, and mast cells) and agranulocytes (monocytes,
macrophages, dendric cells, and natural killer cells)
Adaptive —> specificity and memory, consist of B-cells that produce antibodies, and T-cells that respond to
specific antigens
What are the physical barriers associated with the innate immune system?
External tissues like the skin, mucous, and cilia in the respiratory tract
What can help flush out pathogens from our bodies?
Crying, dedication, urination, sweating serve as exit routes
What are some chemical defenses of the innate immune system? Where can they be found? What do
they do?
Sweat, tears, and sebacous glands secrete enzymes that kill or inhibit pathogens
The extreme pH in the digestive tract also acts as a chemical defense
What role can genes play in our immunity?
Some people have mutations in their genes that inhibit certain viruses from binding to their host cell receptors
Fill in the appropriate characteristics for each of the immune cells
Neutrophils — most abundant, perform phagocytosis and can destroy foreign particles by releasing toxins and
enzymes
Eosinophils — contain peroxidase, lysozyme, and neurotoxins that kill foreign cells, regulate inflammatory
response, target large multicellular eukaryotic cells
Basophils/Mast cells — rarest type, stimulate inflammation by releasing heparin (anticoagulant) and histamines
(basophils in blood and mast cells in tissues)
Monocytes / Macrophages — largest of the WBC, main function is phagocytosis (monocytes in blood,
macrophages in tissues)
Dendritic cells — general phagocytes, found in great quantities in tissues with environmental contact (skin,
mucosa, digestive, respiratory, reproductive tracts), sheet like extensions, travel to lymph nodes once they’ve
eaten something
Natural killer — kill abnormalities by poking holes in cell membrane with molecules called perforins that
induce apoptosis
, What are cytokines? Why are they important?
Communication molecules of the immune system
Allow immune cells to talk to other immune cells and non-immune cells
Cytokines like (interferons) INF are produced by infected cells and used to signal to surrounding cells that
they’re infected
How is the complement system activated? What are the functions of the complement system?
Complement system = system of molecules that complement the actions of both the innate and adaptive parts of
the immune system
Activated in three different pathways:
Classical pathway = complement binds to a complex formed by an antibody and its antigen
Lectin pathway = complement binds to a complex formed by the pattern-recognition receptors (lectins)
that bind to specific carbohydrates found only on microbes
Alternative pathway = low-level spontaneous activation of the system
What are the highways our immune cells and chemicals can take to get throughout the body when/where
they are needed?
The blood and the lymphatic system
Why is inflammation important?
It allows blood flow and capillary permeability to the infected area
Increased blood flow with raise the temperature and can kill some pathogens and significantly inhibit their
movement and growth
The edema helps flush out the infected area and move foreign material to the lymphatic system where there are
millions of leukocytes
Why are fevers important? Is a fever always harmful? What are the substances that cause fever called?
Increased temperatures inhibit pathogenic reproduction and increase the effectiveness of cytokines, adaptive
immune system response, and tissue repair
Fevers are caused by pyrogen molecules
Fevers are harmful when they are high
Adaptive immune system worksheet
Fill in the appropriate characteristics for each of the adaptive immune cells
Cytotoxic T-cell — find infected cells and kill them with permission from T-helper cells
T-helper1 cell — secrete several types of cytokines to help mobilize and coordinate the cell mediated response
(do not want cytotoxic T-cells killing our own healthy cells) to a specific threat, interleukin 2
T-helper2 cell — activate the humoral pathway by secreting cytokines to active B-cell proliferation and
antibody secretion, interleukin 4
T-helper17 cell — secrete interleukin 17 —> promotes inflammation