Download Lymphatic System

Lymphatic
System
By Jenna
Hanson and
Rachel Gaddis
Word Bank:
spleen
lymph node
thymus
Lymph vessels
tonsils
What is the lymphatic
system?
 The lymphatic system is a collection of cells and biochemicals that
travel in lymphatic vessels, and the organs and glands that produce
them.
 The lymphatic system is also known as the immune system.
What does the lymphatic
system do?
Transports fluids
Carries away excess fluid from interstitial spaces
Destroys foreign particles (Immunities)
Destroys toxins and cancerous cells
Lymphocytes
 Type of white blood cell (leukocyte)
 Two types: T-cells and B-cells
 Determines immune response
*Lymphocytes must be activated in order to respond to antigens!*
T and B cells
Lymph Nodes
 Contain large numbers of lymphocytes and macrophages that fight
invading organisms
 Vary in diameter from 1/25 to 1 inch
 Located along lymphatic vessels
 Approximately 500-700 lymph nodes
in the adult human body
Lymphatic Pathways
Prevent backflow of lymph
Begin as lymphatic capillaries
Turn into larger lymphatic vessels
Spleen
(Superior abdomen, Upper left quadrant)
Functions of the spleen
Filters blood (immune system)
Helps to fight certain kinds of bacteria
Recycles red blood cells
Thymus
(Thoracic Cavity, between lungs, connects w/ trachea)
Functions of the thymus
Transform lymphocytes into T-cells
T-cells in the thymus help to fight disease and infection
*The thymus grows less functional with age and is eventually replaced
almost entirely by adipose (fat) tissue*
Lymph Movement
Body Defenses
Innate (nonspecific)
Species resistant: the development of diseases unique to that organism.
Mechanical barriers: Prevent entry of infectious agents, in areas such as the
respiratory, urinary and reproductive systems (Skin and mucus membranes,
and sweat).
Chemical barriers: Enzymes in body fluid that provide the barrier to the
pathogens. Lymphocytes produce hormone like peptides called interferons.
(Viruses/ tumor cells).
Fever: the raise in temperature cause the spleen and liver to take away iron in
the blood which is needed for bacteria/fungi as the temp rises.
Inflammation: blood flow to region of infection increases to isolate and
destroy the infection, however this is painful
Body defenses cont.
Adaptive (Specific)/ Immunity
Antigens: Usually located on cells surface; with the help of lymphocytes
detect foreign antigens.
Lymphocyte Origins: During fetal development, release lymphocytes into the
circulation with later turn to T and B cells.
Types of antibodies
 Immunoglobulin G (IgG): in plasma and tissue fluids, effective
against bacteria, viruses and toxins.
Immunoglobulin A (IgA): Found in exocrine gland secretions (breast
milk, tears, nasal fluid, gastric juices, intestinal juice, bile and urine).
Immunoglobulin M (IgM): Develops in blood plasma in response to
contact with certain antigens in food or bacteria.
Immunoglobulin D (IgD): Found on surface of most B cells. Important
in activating B cells.
Immunoglobulin E (IgE): Found in exocrine secretions. Associated
with allergic reactions.
Immune Responses
Primary response:
Cells release antibodies (IgM, then IgG)
Antibodies are then transported to blood and throughout body
Secondary response:
Following a PR, B cells produce a ‘memory’ cell.
More vigorous of a response than PR.
Autoimmune responses
Sometimes, the immune system accidentally produces
autoantibodies, T cells that attack and damage tissues and organs.
The condition of cells attacking oneself is called autoimmunity
Common auto immune disorders
Type 1 Diabetes
Rheumatoid arthritis
Lupus
Allergic Reactions
Allergic responses are immune attacks against a non-harmful substance
Allergic reactions can vary from inflammation and fever to the closing of
the throat, resulting in inability to breathe.
Common allergens:
Peanuts
Grass
Dairy (Lactose intolerance)
Shellfish
Diseases
Multiple Sclerosis (MS):
Causes pain, blindness, weakness, poor coordination, and muscle spasms
Immune system destroys myelin sheaths in neurons, damaging nerve tissue
Can be suppressed but no treatment
AIDS: Acquired Immune Deficiency Syndrome.
Virus that weakens the immune system
Final stage of HIV
Often Flu like symptoms
Life-threatening
Transmitted through sexual intercourse, contaminated needles, birth and receiving
infected blood (transfusion)
No treatment