Transcript Human Immune System

Human
Immune System
Created by: Bryan Bencomo, Allan
Jones, and Tim Hoskinson
What Does it Do?
• Two most important functions
– Maintenance of fluid balance in the internal
environment.
– Immunity
• Without the lymphatic system, a small
amount of interstitial fluid is left behind,
causing tissue destruction or death
Anatomy
Lymph
• A clear Watery fluid that flows
through lymphatic vessels
• It is essential for the removal of
wastes throughout the body
• After flowing through the lymph
vessels, the lymph gets dumped
into an artery or vein
• Lymph Nodes
Lymph Nodes
– oval-shaped or bean-shaped structures
– Some are as small as a pinhead and
others as large as a lima bean
– When an infection is present, germinal
centers form and the node begins to
release lymphocytes
– The center or medulla of a lymph node is
composed of sinuses and cords.
The spleen is an organ which
is really like a giant lymph
node filled with blood.
Lymph Vessels
• Lymphatic vessels resemble veins in
structure with these exceptions:
– Lymphatics have thinner walls.
– Lymphatics contain more valves.
– Lymphatics contain lymph nodes located at
certain intervals along their course.
• Proteins that accumulate in the interstitial
spaces can return to the blood only via
lymphatics
White Blood Cells
• “Killer” T-Cell
– Sensitized T-cells that release lymphotoxin, a powerful
poison, are called killer T-cells
• “Helper” T-Cell Creates
– Cytotoxic T lymphocytes (CTL), which destroy specific
infected cells,
– B-cells, which produce antibodies
– Natural killer cells, which destroy any infected cells
– Production of antibodies and cytokines
Thymus
• It is composed of two pyramid shaped lobes
• Serves as a final site of lymphocyte
development before birth.
• Soon after birth the thymus begins secreting
a group of hormones collectively called
thymosin that enable lymphocytes to
develop into mature T-cells
• Inherited Immunity
Immunity
– immunity to certain diseases develops before birth
• Natural immunity-Exposure to the causative agent is not deliberate
– Active (exposure)
• A child develops measles and acquires an immunity to
subsequent infection
– Passive (exposure)
• A fetus receives protection from the mother through the
placenta, or an infant receives protection by way of the
mother's milk
• Artificial Immunity-exposure is deliberate
– Active
• injection of the causative agent, such as vaccination against
polio, confers immunity
– Passive
• injection of protective material (antibodies) that was developed
by another individual's immune system
Antibody Animation!!
AIDS
• Acquired Immunodeficiency Syndrome
– Caused by the HIV Virus
– Damaging white blood cells, the virus
stops the human immune system from
functioning
– It can be spread by having contact with
body fluids and other ways
– Eventually the immune system breaks
down since no white blood cells can
identify any disease/virus
– The person eventually dies from an
opportunistic disease; there is no treatment
Hodgkin’s Disease
• Is a lymphoma, type of cancer that develops in the
lymphatic system
• Basically, cells in the body divide too quickly and
a mass of extra tissue is formed
• This prevents the immune system from
functioning properly
• Symptoms include: Swelling in lymph nodes,
fevers, night sweats, and weight loss
• Treatment includes chemotherapy and radiation
therapy, but there is no “cure”.
New Technology
• Advancements in the biotechnology sector have
led to many medical breakthroughs over the last
few years
• Medicines such as Proleukin which helps goad the
body’s immune system were science fiction as
little as 15 yrs. Ago
• New technology is now available which shuts off
the disease-causing messages the gene sends to
the body
• More is in the future though, such as a cure for
AIDS and other so far “incurable” diseases
Bibliography
• BBC Health-Http://www.bbc.co.uk/health/immune/breakdown.shtml
• www.kidinfo.com/health
• The Washington Post-Jan. 08, 2002 “Human Genome Sciences to
Begin Tests of Cancer Drug”
• Encarta Encyclopedia
• UCLA University Wire “Scientists testing HIV vaccines at UCLA”
• www.gened.emc.maricopa.edu
• www.askjeeves.com
• www.howstuffworks.com
• All About You, Raymond V. Hand Jr.
• Funk & Wagnalls’ New Encyclopedia
• www.aids.com
• www.cancernet.nci.nih.gov
• www.Britannica.com
• The Human Body, Charles Clayman
• The Human Body: An Overview, Mary Kittredge