Download Lymphatic System

Lymphatic System
Components of lymphatic system:
• Lymph (watery fluid
collected from
tissues)
• Lymphocytes
• Lymphatic vessels
• Lymph nodes
• Tonsils
• Spleen
• Thymus gland
Functions of the lymphatic system:
• 1. protect from invading organisms
(immune system)
• 2. balance fluids in the body
• 3. absorb fats (lipids)
How lymphatic functions occur?
• 1. protect from
invading organisms
– The lymphatic system
does this in 3 ways:
• Lymph nodes filter
microorganisms and
other foreign
substances from the
lymph
• The spleen filters the
blood
• Lymph cells attack and
destroy microorganisms
Functions continued:
• 2. fluid balance
– Removes fluid (lymph)
when it is in excess to
prevent swelling
– Ex. Your stomach
swells when you eat
and drink but after a
few hours the
decrease occurs due
to digestion and the
removal of lymph by
the lymph vessel
– These vessels are
found all over the body
Functions continued:
• 3. fat absorption
– Absorbs fat from the
digestive tract
– There are special cells
that absorb fat called
lacteals
– The lymph with the fat
in it is called chyle
intestines
Lymph passage in the body:
• Lymph- watery
substance removed from
the tissues
• Lymphatic vessels- only
remove lymph from the
tissue- (does not take it to
tissues)
• Lymphatic capillariestiny vessels that remove
lymph form the tissue and
take it to larger lymph
vessel and then to the
blood
-found in all tissues except the
CNS, bone marrow, epidermis,
and cartilage
How does the body know to take
lymph away from the body tissues?
• All lymphatic vessels have
vessels that have a 1 way
valve which keeps lymph from
going backwards into the
capillaries
• 3 things force the lymph
from the capillaries to the
larger vessels:
– Contraction of surrounding
skeletal muscles
– Contraction of smooth muscle
in the vessel walls
– Pressure changes in the
thorax during respiration
How does lymph get from the
lymphatic vessels to the blood?
• Lymphatic ducts- empties the lymph from the
right upper area of the body into the blood
• Thoracic ducts- empties the rest of the body to
the blood at the subclavian vein
Lymphatic organs:
• Tonsils
• Lymph nodes
• Spleen
Make-up of lymphatic organs:
•
•
1.
2.
All are composed of cells
called lymphocytes
the lymphocytes will
divide and increase in
number when foreign
microorganisms contact
them
Functions of
lymphocytes:
They attack and destroy
invaders and
form fiber networks to filter
out foreign matter
• Function: protect the
openings of the oral
cavity and throat from
harmful materials
entering
3 kinds of tonsils:
• 1. Palatine- located at
the sides of the throat
• 2. Pharyngeal- located
near the internal nasal
opening
– When it becomes enlarged,
it is called an adenoid
• 3. Lingual- on posterior
surface of the tongue
Tonsils
Found at the opening
of the throat
Tonsil Disorders:
• Since tonsils filter out
infections, they
sometimes become
chronically infected
and inflamed
• Tonsillectomyremoval of inflamed
tonsils
Lymph Nodes:
• Rounded structures
found along lymphatic
vessels
• 3 main areas where
nodes are found:
• Groin
• Armpits
• neck (cervical area)
Functions of lymph nodes:
• 1. activate the immune
system- when
microorganisms enter the
nodes the lymphocytes are
triggered to start dividing
and attack the foreign
matter
• 2. remove
microorganisms and
foreign substances from
the lymph by special cells
called macrophages
How do the lymph nodes filter
material?
• Lymph enters the nodes
through the afferent
vessels.
• Lymph is filtered and then
exits the nodes through the
efferent vessels
(these are smaller making
lymph stay in the nodes
longer before it exits
Spleen
• Located on the left
superior corner of the
abdomen
4 functions:
• 1. filters blood (not lymph)
• 2. detects and destroys
foreign substances
• 3. Destroys old red blood
cells
• 4. blood reservoir- stores
blood which is available
in an emergency
Thymus gland:
• Located at the top of
the sternum
Function:
• Where lymphocytes
are produced and
mature. They are
released into the
blood to go to other
lymphatic structures
Lymphatic disorders:
• Elephantiasis- due to
mosquitoes injecting
a parasitic worm into
the body
• The worm reproduces
rapidly and blocks the
flow of lymph to the
limbs.
• It results in the limb
(where the blockage
occurs) swelling
enormously.
Lymphatic disorders:
• Bubonic plague- due
to ingestion of rat
feces and rat fleas
• Bacteria accumulates
in the lymph nodes
• Swell especially in the
groin area
• (called blood
poisoning)
What does it mean to be immune
to something?
• Immune- the body remembers a
substance and it destroys it
before is has an effect
• The substances the body
recognizes are called antigens.
• There are 2 types of antigens:
1. Foreign- introduced from
outside the body example:
bacteria
2. Self-antigens- molecules
produced by the body that the
body must fight off
Example: tumor
How does the body destroy
foreign antigens?
• Uses antibodies
• Antibodies- proteins
the body produces in
response to being
exposed to certain
antigens
– Have a Y-shape
– It attacks and
inactivates antigens
Immunity:
• Ability to resist damage from foreign substances like
microorganisms, chemicals and toxins
2 types of immunity:
• 1. innate immunity- the body is born with the ability to
recognize and destroy foreign substances (example:
white blood cells attack infections)
• 2. acquired (adaptive) immunity- ability of the body to
recognize and destroy foreign substances exposed to
before
– It improves each time the body encounters the
substance
– Ex. vaccinations
4 ways immunity is acquired:
1. active natural immunity- results from direct
exposure naturally to disease causing antigens
(ex. Chicken pox)
2. active artificial immunity- deliberately introduce
antigens to an individual to stimulate the immune
system
(ex. Tetanus, mumps)
Acquired immunity continued…
3. passive artificial immunitybegins with the vaccination of an
animal (ex. Horse)
-Once the animal is immune to the
antigen, the antibodies are
removed and injected in an
individual. The persons body will
immediately attack the antigens
they are exposed to.
Antiserum- antibodies are in a
serum-it is microorganisms that are
injected like rabies, hepatitis
4. passive natural immunitytransfer of antibodies from the
mother to the fetus across the
placenta. The mother’s antibodies
go to the child and the child is
protected against the same
antigens. This is the benefit of
breast feeding.
Inflammatory response:
• When unwanted antigens enter the body, the areas
become inflamed and chemical mediators are
activated to fight it
• this tells the body there is an infection
2 kinds of
inflammatory
responses:
1. Local inflammationinflammatory response
is confined to a
specific area of the
body
• Symptoms of
inflammation are:
–
–
–
–
–
Redness
Heat
Swelling
Pain
Loss of function
• 2. systemic
inflammationinflammatory response
occurs in many parts of
the body
• Has symptoms like local
inflammation but also has
3 other symptoms:
• Red blood cells release
substances that fight the
infection
• Fever
• In extreme cases, shock
or death
Autoimmune disease
• Occurs when
antigens produced by
the body cause
unwanted destruction
of the body tissues
• The body attacks
itself
• Ex. Rheumatoid
arthritis