Download The Immune Systems

The Immune System
Lesson 1:
The Immune Systems
Lesson Objectives
Upon completion of this lesson, students should
be able to …
 Identify and discuss the anatomy of the
immune system.
 Discuss the functions of the immune system.
 Explain the immune system and its response.
Composition of the Immune
System
 Tissues
 Organs
 Physiological processes that identify abnormal cells
 Foreign substances
 Foreign tissues, such as transplants
Structures Central to the
Immune System
 Central lymphoid tissue
 bone marrow, thymus
 Peripheral lymphoid tissue
 lymph nodes, spleen, and mucus
membranes
Critical Thinking Questions
1.
What is so critical about the immune system to one’s
overall health?
2.
If one has a compromised immune system would
that shorten the person’s life?
The Immune System






throughout the body
part of the lymphatic system
subsystem of the CV system
Primary fx is to defend against invasion
Pathogens (viruses, bacteria, and fungi)
Immunosuppressants, medications, and stress can
suppress system
The Lymphatic System
Watch This
 http://www.cbsnews.com/video/watch/?id=6944753n
Bone Marrow
 Contains stem cells that create all the cells
 Produces
 RBC’s
 WBC’s
 Platelets
 B cells
 Natural killer cells
Thymus Gland
 Located posterior to the sternum
 Manufactures infection-fighting T cells
 Helps distinguish normal T cells from those that attack
the body
 Enlarges during childhood
 Shrinks as we age
Peripheral Lymphatic System
 Consists of the lymph nodes, spleen, and
other lymphoid tissue
Lymph Nodes
 Different sizes and
shapes
 Most are bean-shaped,
about 1 inch long
 Covered with a thick
fibrous capsule
Two Parts of Lymph Nodes
 Cortex
 Populated mainly with lymphocytes
 Medulla
 Primarily made up of macrophages
B Lymphocytes
 Responsible for circulating antibodies
 When an antigen enters the body,
 B lymphocytes rapidly undergo mitosis and divide
 This produces a large quantity of an antibody
Spleen
 Located in the ULQ of the abdomen
 Lots of blood vessels
 Spleen’s blood vessels are lined with macrophages
 swallow and digest debris in the blood

worn-out red blood cells and platelets
Tonsils
 Located in the
depressions
 of the throat and the
pharynx
 Fx -filter bacteria
 aid in the formation of
white blood cells
Factoid:
Tonsils used to be
removed when infected.
Immune Troop Worksheet
 http://vimeo.com/138062
The Immune System
 Defense against infectious organisms and pathogenic
invaders
 Immune response
 cells, tissues, and organs work together to attack
pathogen
 white blood cells (WBCs), seek out and destroy
harmful organisms
Phagocytes
 Phagocytes
 WBC that attacks the invading organism
 most common are neutrophils, which fight off bacteria
Lymphocytes
 Lymphocytes
 WBC allows the body to remember previous
invading organisms
 Originate in the bone marrow
 If stays there, it matures into B cells
 If moves to the thymus gland, they mature
into T cells
B and T Lymphocytes
 B lymphocytes
 Seek out invading organisms
 and send defenses to attach onto them
 T cells
 Destroy the organisms that the B
lymphocytes have id
Antigen
 Foreign substance that invades the body
 When an antigen is detected, several types of cells
work together to recognize and respond to it
 These cells trigger the B lymphocytes to produce
antibodies
 This process is known as humoral immunity
Antibodies
 Specialized proteins that lock onto specific antigens
 Immunoglobulins
 Antibodies are found in blood, tissue fluids, and many
secretions
B Cells of the Immune System
 Once antibodies have been produced, they remain in
the body
 If re-infected, the antibodies are already there to
neutralize it
 antibodies can recognize an antigen and lock onto it,
but are not capable of destroying it.
 That is the job of the T cells.
T Cells
 destroys antigens which have been tagged by
antibodies
Immunity
 The body’s ability to defend itself against
pathogens
 3 Forms
Innate Immunity
 Born with innate, or natural, immunity
 Renders many of the viruses and bacteria
incapable of harming infant
 Provided by :
 Skin
 Mucous membranes
 Mother
Active Immunity
 by infection or with a vaccine
 Is permanent ??
Types of Active Immunity
 Acquired active immunity
 exposed to a live pathogen
 develops the disease
 and becomes immune (primary immune response)
 Artificially acquired active immunity
 induced by a vaccine (antigen)
 stimulates a primary response against the antigen
 without causing symptoms of the disease
Passive Immunity
 “Borrowed” from another source and lasts for only a
short time
 An inherited immunity to certain diseases
Medical Specialists
 Allergist
 Immunologist
 Oncologist