SOLUTIONS TO EXERCISES, LESSON 1
1.
Immunity is defined as the physical, chemical, and cellular defense against
antigens. Immunity also refers to specific activities of certain body cells and/or
chemical constituents of body fluids that aid in the body's defense. (para 1-1)
2.
There are two types of immunity: innate and acquired. In innate immunity, the
disease-resisting ability is a result of one's genetic makeup, and not acquired by
exposure to infectious agents. In contrast, acquired immunity develops after birth
and as a result of contact with a foreign substance. (para 1-2)
3.
Innate immunity is also known as natural immunity or inherited immunity. Innate
immunity refers to that type of resistance which each individual has by virtue of
being the individual he or she is in genetic terms, such as species and other
factors. Natural immunity is commonly thought of as a nonspecific barrier that is
effective against many different kinds of infectious agents. (para 1-2a)
4.
Acquired immunity is the type of immunity which an individual develops during a
lifetime. It is antigen specific and may be based on antibodies or may be cell-
mediated in origin and more closely associated with the activities of macrophages
and T lymphocytes. This form of immunity is subdivided into that which is actively
acquired and that which is passively acquired. In active immunity, the individual
synthesizes his or her own antibodies. In passive immunity, the individual
receives antibodies from some other individual. Both active and passive immunity
are subdivided into two categories, depending on whether the immunity is
acquired by natural or artificial means. (para 1-2b)
5.
Active immunity refers to that type of immunity in which production of significant
amounts of antibody occurs about 7 to 14 days after initial exposure to antigen.
(para 1-2b(1))
6.
Active immunity may be naturally acquired either by having a subclinical infection
with a particular microorganism or by actually having the disease.(para 1-2b(1)(a))
7.
The immunity resulting from the injection of a vaccine or toxoid is said to be
artificially acquired active immunity. Killed and attenuated strains of bacteria and
viruses now are widely used forms of immunization against many diseases; for
example, tuberculosis, mumps, poliomyelitis, yellow fever, and measles.
Artificially acquired active immunity against tetanus and diphtheria is created by
the injection of toxoids, which are detoxified but still antigenically active poisons
excreted by bacteria. (para 1-2b(1)(b))
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