Download Lymphatic system

LYMPHATIC SYSTEM
Associated with the Blood and Cardiovascular System
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http://www.lymphnotes.com/article.php/id/151/
http://www.youtube.com/watch?v=qTXTDqvPnRk
http://www.scribd.com/doc/60675255/HandoutsLymphatic-System-F11
http://www.learningace.com/doc/5949560/9178
e2f0064b410c8c8e9218bcc748e6/ama-180course-handouts
Lymphatic System
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Lymph Fluid
Lymph Vessels
Lymph Nodes
Four Organs
 Tonsils
 Spleen
 Thymus
Gland
 Peyer’s Patches
Functions
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Drain from tissue spaces, protein-containing fluid
that escapes from the blood capillaries
Transport fats from the digestive tract to the blood
Produce lymphocytes
Develop Immunities
Interstitial Fluid
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Blood pressure forces some of the blood plasma
through the single-celled capillary walls
Interstitial Fluid is in the spaces between cells
Most is reabsorbed into the capillaries
Some fluid is not and must be drained from the
tissue spaces to prevent swelling or Edema.
Lymphatic Capillaries – drain this fluid
 Lymph
is the fluid when it is in the vessels
Fat Absorption
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Lacteals – lymphatic vessels in the villi of the small
intestine that absorb fats and transport them to the
blood.
Looks milky because of the fat content and is called
chyle.
Lymphatic Vessels
Lymph Capillaries
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Larger and more permeable than blood capillaries
Closed at one end
Occur singly or in extensive plexuses
Lymphatic Capillaries
Lymphatics
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Combined capillaries
Larger
Beaded appearance
Similar to veins, but thinner walls and more valves
 One
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way valves to prevent backflow
Lymph goes in one direction only
Have lymph nodes at various intervals
All Lymphatics converge
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Thoracic Duct – the main collecting channel, Left
Lymphatic Duct
Right Lymphatic Duct
Lymph Nodes or Lymph Glands
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Regions of aggregations – groin, armpits, neck
Oval to bean-shaped structures found along the
length of lymphatics
1 to 25 mm in length
Look like small seeds or almonds
Framework consists of the capsule, hilum and
trabeculae
Lymph Node
Structure of a Node
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Hilum - Depression on one side of the node
 Efferent
Lymphatic Vessels leave
 Nodal artery enters
 Nodal vein leaves
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Covered by a Capsule of fibrous connective tissue
that extends into the node
 Trabeculae
– divide the node internally into
compartments that have lymphatic sinuses and tissue
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Afferent Lymphatic Vessels – enter the node ad
various sites
Lymphatic Tissue
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Cortical or Lymph Nodules
6 different kinds of lymphocytes
Germinal Center – produces lymphocytes
Lymph Sinuses – spaces between the lymphatic
tissue
 Network
of fibers and macrophage cells
At the Node – a Sequence of Events
1.
2.
3.
4.
5.
6.
Lymph enters by an afferent lymphatic
Immune response is activated
Lymphocytes produced by germinal centers as a
response to any microorganisms or foreign matter
Lymphocytes released into lymph
Eventually reach the blood and stimulate antibody
production
Macrophages remove dead microorganisms and
foreign substances by phagocytosis
Lymph Circulation
Blood to Lymph
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Blood plasma is filtered by blood capillaries
Passes in-between cells to become interstitial fluid
Passes into the lymph capillaries to become lymph
 Water,
plasma solutes (ions & gases), nutrients, proteins,
(hormones & enzymes), and waste products
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Lymph drains into lymph capillaries and lymph
plexuses
Drains to Lymph vessels
Heads towards Lymph Nodes
At the Node
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Afferent Vessels drain lymph into the node sinuses
Microorganisms and foreign substances trigger
lymphocytes to divide and activate immune
response
Macrophages engulf foreign bodies
Efferent Vessels leave the node and go to other
nodes or join with other vessels
Unite to form Lymph Trunks
Moving the Lymph Along….
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Skeletal muscle contractions compress lymph vessels
and force the lymph through the one-way vessels
Normal movement helps circulate the lymph
Breathing causes pressure changes in the thorax
that help move the lymph
Smooth muscle contraction in the lymph vessels
Swelling or edema – a blockage in the vessels
cause a back up interstitial fluid between the cells
Efferent Vessels Unite
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Form Lymph Trunks
 Lumbar
– lower extremities, walls and viscera of pelvis,
kidneys, adrenals, abdominal wall
 Intestinal – stomach, intestines, pancreas, spleen,
surface of liver
 Bronchomediastinal – thorax, lungs, heart, diaphragm,
rest of liver
 Intercostal – portions of the thorax
 Subclavian – upper extremities
 Jugular – head and neck
Trunks to Channels to Veins
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Thoracic Duct – empties into the left subclavian vein
Right Lymphatic Duct – empties into the right
subclavian vein
Completing the Cycle
Organs of the Lymphatic System
Tonsils, Spleen, Thymus Gland, and Peyer’s
patches
Tonsils – three groups
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Palatine Tonsils – removed in a tonsillectomy, sides
of the oral cavity
Pharyngeal Tonsils – adenoids, near the nasal
cavity, when swollen interfere with breathing
Lingual Tonsils – back surface of the tongue at the
base
Ring of protection for the nose and oral cavity from
microorganisms
 More
functional in children
Spleen
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Oval, 5 inches in length
Left upper corner of the abdominal cavity
Largest mass of lymphatic tissue in the body
Filters blood
Phagocytizes bacteria, worn-out platelets, and RBCs
Release hemoglobin to be recycled
Produces lymphocytes and plasma cells
Stores blood – blood reservoir
 Extra
blood when a hemorrhage occurs
Thymus Gland
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Bi-lobed mass of tissue along the trachea behind
the sternum
Also part of the Endocrine System
Site for lymphocyte production and maturation in
the fetus and infants
Peyer’s Patches
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Aggregated Lymphatic Follicles
Wall of small intestine
Similar to tonsils
Macrophages destroy bacteria to prevent infection
in the walls of the intestine
Resisting Infection
Immunity, Antigens, Antibodies, Immune Response
Cells
Immunity
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The ability of the body to resist infection from disease
causing microorganisms or pathogens, damage from
foreign substances and harmful chemicals
Lymphocytes
B Lymphocytes – humoral (body fluids) immunity; produce
antibodies; circulating bacteria and viral infections; attack
the invading agents, become plasma cells in the tissues
 T Lymphocytes – cellular immunity; from the thymus gland;
fungi, parasites, inside the cells viral infections, cancer cells
and foreign tissue implants
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What Microorganisms ?????
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Protozoans
Bacteria
Virus
Fungi
Malaria
Protozoa
Antigens and Antibodies
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Antigens – foreign proteins that gain access to the
body via an opening in the skin, or through the
digestive, circulatory, urinary or reproductive
systems.
 Cause
immune system to produce Antibodies or
Immunoglobulins to destroy this invader
 High
molecular weight proteins
Active Immunity
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B-Lymphocytes produce antibodies against an
antigen that they came in contact with
Naturally acquired when you come in contact with a
bacterial or viral infection
Vaccines are a killed or weakened pathogens that
stimulate antibody production
 Measles,
smallpox, polio, tetanus, chickenpox,
pneumonia, diphtheria, and flu
Passive Immunity
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Conferred naturally when a fetus receives mother’s
antibodies through the placenta
Artificially – gamma globulin, breast milk or immune
serum
Used after exposure to hepatitis
Snakebite, botulism, or rabies
Cells of the Immune Response
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B cells
Plasma Cells
Helper T Cells
Killer T Cells – kill virus invaded body cells and
cancerous body cells, graft rejections
Suppressor T Cells
Memory Cells – respond to future infections with the
same pathogen
Macrophages – engulf and digest antigens
Monokines and lymphokines