Test Bank For Basic Immunology, 7th - 2024 All Chapters - 9780443105197.pdf

Basic Immu
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nology

Second year b




Laboratory medicine
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,
, Introduction to immunology b b




Immunology:

Immunology is the science that studies the mechanisms by which human body
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defends itself from foreign substances present in the environment. It is divided
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into three major parts:
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1. Basic immunology. b



2. Diagnostic immunology. b



3. Clinical immunology. b




Part I-Basic immunology
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History:

Immunity is derived from the Latin word immunitas and was referred to the ex
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emption or protection of Romans senators from various customs duties, legal l
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aws and legal prosecution. The word is then used in medicine to refer to the pro
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tection of the body from microbes. The cells and molecules that protect body f
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rom microbes constitute the immune system. The collective and coordinate
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d reaction between the immune cells and molecules to get rid of microbes is ter
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med the immune response.
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Historically, immunity meant protection from infectious diseases. Later on, sci
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entists found that immune system protects the body not only from infectious a
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gents but also from foreign macromolecules (such as proteins and polysacchar
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ides) and from abnormal cells (such as tumor cells, senescent cells and foreign
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cells).
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, They also found that in some individuals, the immune response that protects th
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e body causes tissue injury (either local or systemic injury).
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Immunity:

Immunity is the protection of the body from foreign substances such as microb
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es (bacteria, viruses, fungi, and protozoa), macromolecules (proteins, peptides
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, and polysaccharides), foreign and abnormal cells without causing any tissue
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injury to the host. b b b




Types of immunity: b b




1) Innate immunity: It is the first line of defense against an antigen.
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2) Adaptive immunity: It is the second line of defense.
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Although these two arms of the immune system have distinct functions, both in
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nate and adaptive immunity interact at several levels to develop a complete def
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ense against foreign substances. In other words, the components of innate imm
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unity influence the adaptive immunity and vice versa.
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Innate immunity (native, non-specific, natural)
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Innate immunity refers to resistance which is present in all normal individuals
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from birth, and once activated the same mechanisms occur regardless of which
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foreign substance or previous exposure to the same antigen.
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Innate immunity provides immediate defense. It has a limited capacity to distin
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guish one microbe from another or the types of foreign macromolecules. It lac
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ks immunological memory, i.e. it is unable to remember. It involves the same
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mechanisms every time the same antigen entered the body. Innate immunity n
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ot only provides rapid defense against
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