Anatomy & Physiology 34B Lecture
Chapter 21 – Immunity
I. Overview
A. Immune System Functions
B. Pathogens of the Body
C. Response to different pathogens
D. Innate immunity: nonspecific body defenses
E. Acquired immunity: antigen specific defenses
1. Cell mediated immunity
2. Antibody mediated immunity
F. Immune disorders
II. Functions of the Immune System
A. Immune system functions
1. Protects the body from invading ____________, including
a. _________ – bacteria, viruses, fungi, and one-celled protozoans
b. Multicellular ____________, such as tapeworms & hookworms
c. Other “________” cells or molecules, like pollen and chemicals
d. Anything with foreign ____________ may produce an immune response in the body
2. Removes _______ and damaged cells and tissues
3. Tries to recognize and remove _________ cells (e.g., cancer cells)
B. Leukocytes (______s) functional groups include
1. ________cytes – macrophages (derived from monocytes), neutrophils, and possibly
eosinophils, that ingest pathogens
2. ____________ cells – eosinophils and some lymphocytes that kill the cells they attack
3. Antigen-presenting cells (______s) – macrophages, dendritic cells, and some
lymphocytes that present fragments of foreign proteins on their cell surface, forming
major histocompatibility (_______) complexes
C. Pathologies of the immune system
1. ______________ responses – autoimmune diseases in which the immune system attacks
the person’s own tissues
2. _____________ responses, such as anaphylactic allergic reactions
3. ________ of response, in which the immune system fails to work properly (e.g., in
AIDS)
III. Pathogens of the Human Body
A. ____________ are microscopic single-celled organisms that feature
1. Cell membrane surrounded by a cell wall and sometimes a ______
2. Most can survive outside a ________ with necessary requirements
3. _______________ can be used to kill most bacteria
B. ___________ are not cellular; features are
1. Nucleic acid (______ or ______) core surrounded by a
2. ___________ coat of proteins
3. Some viruses have an additional ____________ of phospholipids and proteins obtained
from the host cell membrane
4. Are all ___________ – they require a living host cell to reproduce
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5. Antibiotics do not kill viruses, but some _____________ drugs do
IV. The Immune Response
A. ______________ has two components
1. __________ & chemical barriers, such as skin, mucus, and HCl that prevent pathogens
from entering the body
2. ______________ immune response, which consists of
a. _____________ and identification of a foreign invader
b. _______________ among immune cells to rally defenses and coordinate responses
c. ____________ or suppression of the invader
B. Immune __________ is divided into innate and acquired immunity
1. ______________ (nonspecific) immunity
a. Present from birth, is a ______________ immune response (doesn’t target a specific
pathogen)
b. Response begins within ________ to hours (e.g, inflammation)
2. _______________ (specific) immunity
a. _____________ as the body is exposed to pathogens
b. Is _____________ for a particular pathogen
c. Response can take hours to _______
d. ____________ immunity is subdivided into cell-mediated and antibody-mediated
immunity, both mediated by ____________
1) _______-mediated immunity refers to an attack against infected body ________
by ___ cells
2) __________-mediated immunity refers to the production of __________ by __
cells against foreign antigens on pathogens
V. ____________ immunity: nonspecific body defenses
A. First line of defense – ____________ & chemical barriers
1. ______________ resistance means that the body guards equally against a broad
________ of pathogens and does not require prior exposure to the pathogens
2. The body’s first line of _________ involves the skin and mucous membranes, which
block initial pathogen entry via
a. ________’s dead keratinized surface cells and antimicrobial chemicals, such as
lactic acid in sweat and __________
b. Mucous membrane sticky _______ traps microbes and ________ in the respiratory
tract sweep them up and out
c. Mucous, sweat, and saliva also contain _____________ that destroys bacteria
d. Strong ______ acid in the stomach kill many ingested bacteria
B. _____________ recognize foreign material & ingest it
1. ________phages and ______phils are phagocytic cells that ingest and destroy invading
pathogens
2. ______________ is a defensive response to infection and trauma, characterized by
redness, swelling, heat, and pain. Stages include
a. Mobilization of defenses – ________ _________ proteins (e.g., C-reactive
protein), released by the liver in response to microbial invasion, prevent tissue
damage; in addition ______ cells (and basophils) secrete
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1) _____________ that causes blood vessels in the area to vasodilate and become
more permeable (porous), as well as
2) _____________, which prevents blood clotting and allows more WBCs to arrive
b. Containment & destruction of pathogens – ______phils and ________phages
migrate through blood vessel pores (____________) and phagocytize the
microbes.
c. Tissue cleanup & repair- macrophages phagocytize ______, damaged cells, and
dead neutrophils, forming _____.
C. ______________ are cytokines that allow WBCs to communicate
1. Interleukin-1 (IL-1), secreted by activated macrophages mediates ___________ and
immune response by
a. Alters blood vessel _____________ to allow phagocytes and proteins squeeze out
during inflammation
b. Stimulates production of ______ ________ proteins by the liver
c. Is a _____________ that causes the hypothalamic thermostat to produce a fever.
d. Stimulates ___________ and endocrine secretion by other cells
D. ________________ also causes vasodilation, and stimulates pain receptors at the injury site
E. Complement ____________ assist in defeating the enemy
1. ______________ refers to a group of about 25 plasma and cell membrane proteins;
includes opsonins and chemotaxins
2. _______ (e.g., antibodies) “tag” bacterial proteins for destruction, and _____________
attract phagocytes to ingest the bacteria
3. Complement proteins can also form a membrane attack complex (MAC) that form
________ in a foreign cell’s membrane so that ions and ________ flood in and bursts the
cell
F. __________ _______ (NK) lymphocytes eliminate virus-infected & tumor cells
1. ______ cells induce virus-infected cells to commit suicide (_______________) before the
virus can reproduce
2. NK cells and other lymphocytes secrete antiviral ____________ (proteins that affect cell
activity), such as gamma-interferon (______________ interfere with viral reproduction)
VI. _____________ (adaptive) immunity: antigen specific responses that include cell-mediated
and antibody-mediated immunity
A. ________-mediated immunity is carried out by ___-lymphocytes that differentiate to form
1. ________ T (killer or CD8) cells bind to specific foreign _______ in MHC I proteins on
the surface of abnormal body _______ (e.g., virus-infected & cancer cells). They destroy
the abnormal cells by
a. Release of __________ that ruptures the target cell membrane
b. Secretion of ____________ (digestive enzymes)
c. Activation of _______ in the target cell that cause ___________ (cell death)
2. ________ T (CD4) cells are activated by specific foreign _______ in MHC II proteins on
______s, such as macrophages. Once activated they secrete ____________, such as
a. Gamma-___________, which activates macrophages
b. _______________ that activate cytotoxic T cells and antibody production by B cells,
and also promote the production of eosinophils and mast cells
c. __________-stimulating factors that promote WBC production in bone marrow
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d. Helper T cells also bind to ____ cell antigens and cause them to divide into ________
B cells and _________ cells that secrete antibodies
e. The ______ virus infects and destroys _______ T cells, resulting in Acquired
Immunodeficiency Syndrome (_______)
3. ____________ T cells secrete suppression factors to decrease the responses of other T &
B cells once the pathogen is destroyed
4. ____________ T cells can differentiate into more cytotoxic and ___________ T cells if
the same antigen is encountered again
B. ____________-mediated (humoral) immunity is accomplished by ___-lymphocytes,
which become plasma and memory cells
1. B cells carry ____________ in their cell membranes, which bind to foreign
_____________ in the interstitial fluid
2. The antigens are incorporated into _____ ___ proteins on the B cell surface
3. _________ T cells sensitive to the same antigen bind to the B cell antigen and secrete
__________ that
a. ___________ B cells
b. Promote B cell _________ to produce plasma & memory cells
c. Stimulate __________ cells to produce and release __________ against the antigen
4. _____________ are “Y” shaped proteins composed of one pair of long heavy chains
attached to one pair of short light chains. Antibodies bind to specific ______ on
extracellular pathogens and
a. Act as ___________, coating and labeling the pathogen so other WBCs will attack
them
b. Cause ___________ (clumping) & precipitation of the pathogen
c. ____________ (inactivate) some bacterial toxins
d. Activate _____________ proteins that destroy the antigen
e. Stimulate ________ cells & basophils to release histamine and ___________
f. Activate other _________ cells (i.e., NK cells, cytotoxic T cells, and phagocytes) to
destroy the pathogen
5. Classes of _____________ (immunoglobulins = Ig) include
a. _____ – most numerous antibodies; defend against many _______, bacteria and their
toxins
b. _____ – first antibody secreted with antigen encounter; anti-__ & anti-__ types
responsible for incompatible blood type reactions
c. _____ – found in tears, _______, saliva; attack pathogens before they enter tissues
d. _____ – on surface of ______ cells & basophils; accelerate inflammation when
exposed to antigen
e. _____ – bind antigens in the ECF to ___ cells; may activate B cells
6. ____________ B cells remain in the body for years and divide rapidly into ________
cells if the same antigen is encountered again (the reason we don’t usually get the same
disease again)
VIII. Disorders of the Immune System
A. _____________ disorders are those in which a body’s immune system attacks and
destroys its own tissues, such as
1. _______________ arthritis (RA) – antibodies attack connective tissues in the joints
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2. Insulin dependent ___________ mellitus (IDDM) – antibodies destroy pancreatic beta
cells that secrete _________
3. Multiple ____________ (MS) – antibodies attack the ________ sheath around nerve
fibers
B. ____________deficiency diseases involve a failure of the immune system, and include
1. Severe Combined Immunodeficiency (_______) – rare disorder in which a child is
born with few or no ___ and ___ cells. As a result the child has no ____________ and
usually dies of a minor infection
2. Acquired Immunodeficiency Syndrome (_______) – caused by infection by _____
virus that destroys _________ T cells, which makes the body vulnerable to
opportunistic infections
C. _____________ are inappropriate or excessive immune responses to ____________, such
as those in pollen and bee venom
D. __________ and immune response
1. ______________-1 is secreted during the immune response, promoting inflammation,
and stimulating the release of ACTH
2. _________ causes the release of glucocorticoids (e.g., ________) by the adrenal cortex
3. Gluco__________ control the intensity of the immune response, but with continued
stress can __________ the immune system
E. Manipulating the immune response
1. _____________ immunity refers to the protection provided by injecting ___________
produced in another animal (as opposed to __________ immunity in which the body
produces its own antibodies)
2. _____________ antibodies are produced by injecting a pathogen ____________ into an
animal, allowing it to produce __________ against it, then harvesting the antibodies to
use in treating disease