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Lecture 5

Kins 140 Lecture 5 Prof Arnold


Department
Biomedical Physio & Kines
Course Code
BPK 140
Professor
Anne- Kristina Arnold
Lecture
5

Page:
of 4
kins 140
lecture 5 Infectious Disease 2
September 22
The Immune System:
-combating infectous disease
-development of diseases
Innate Immunity:
-defenses our body has to address pathogen (not to specific pathogen)
Acquired Immunity:
-ability to recognize specific foreign substances
The body’s defenses against infectious diseases
external:
-mechanical barriers
-skin, depends on being unbroken, healthy nutrition maintains turnover
-mucous membranes, nasal and pubic hairs, cilia, eyelashes
-blinking, sneezing, coughing, vomiting.
chemical defenses:
-secretions: sebum of skin, saliva, tears, acid in gut, genital
-enzymes, acid
Internal
-general systemic responses:
-inflammatory response
-histamine release from mast cell swelling (to contain
infection or injury)
-cytokines: provides msges to immune system to kick in.
-Fever -cytokine pyrogens
-can be harmful, but paradoxically it can be protctive
-increased body temp (by one or two degrees) kills many agents
and increases white blood cell activity
Acquired Immunity
-the process of priming the body to remember an encounter with a specific antigen
-get the body to remember how to deal with a pathogen
Active:
-body produces own way to recognize and deal with specific pathogen (memory to get
rid of it)
-builds immunity
Passive:
-antibodies are made by another organism (natural-breast milk)
-occurs with injection of antibodies or tranfer of antibodies from mother to fetus across
placenta or to newborn in breast milk (conferred)
The immune response
Humoral immunity:
-protection provided by antibodies
-antibodies are made to be specfic to an antigen on a pathogen
-once the immune system has been exposed to a pathogen it can recogn. it more
quickly if exposed later
Cell-mediated immunity
-T-cells manufactured in bone marrow
-These are cells destroyed by HIV
Cells of the Immune system
Macrophages:
-phagocytes (eats pathogen, destroy antigens by eating them releasing to body
for recognition)
-display antigen fragments on their cell surface to activate other immune cells)
T lymphocytes:
-white blood cells
-involved in activating other immune cells, secreting chemicals and attacking and
destroying pathogens
eg:
-CD4L helper T cells: messengers that release msging agent that brings the
macrophages to the pathogen
-Killer Tcells: destroy the pathogen directly.
B lymphocytes
-secrete antibodies that will recognize antigens
-bind to antigens, labeling them for other immune cells to recognize and destroy
-are unique for each different antigen
antigen-antibody complex: when antigen is attached with B cells (see image)
Memory cells:
-allow immune system to remember antigens that it has already been exposed to
-immune response is faster and stronger upon second exposure to an antigen
Immune Response
1) recognition:
-macrophages consume some of the invading organisms
-display antigen on their surface
2) Amplification
-helper T cells multiply, stimulate production of killer T and B cells
-cytokines help regulate and coordinate response
-allow communication between immune cells
examples:
-interferon
-histamine
3) Killer T cels destroy pathogens and invaded cells
-stimulate amplification of inflammation and recruit more macrophages to clean
up
-cellular reponse
B cells produce antibodies to d
4) Slowdown by suppressor T cells
-clean upL clean dead cells, killed pathogens
*know how the cells work and the name of the cells
Allergies: Your immune system running amok
-allergies
-allergens: pollen, dander, dust mites, molds, food, insects
-The allergic response (immunoglobulin (IgE):
-anaphylaxis: a severe shutdown of system due to exposure of allergies (stop
breathing, hurts shut down=very rare!)
-Dealing with allergies
-avoidance
-medication
-immunotherapy
Stages of Infectious Disease
1)incubation: (latency period) period between initial infection to the development of
signs/symptoms. Still infectious during that period
-Cold about 4 day
-HIV up to 10 years
2) Prodromal: not feeling well but non specific complains: infectious
3) Acme: Most severe, most contagious. Symptoms
4) Convalescence: regaining normal function possibly still contagious
Vaccination:
-giving someone a preparation of a dead or weakened pathogen