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    Lymphatic DrainageLymphatic Drainage

    Alex ForrestAssoci ate Profess or of For ensic Od ontol ogyForensic Science Research & Innovation Centre, Griffith UniversityConsultant Forensic Odontologist,Queensland Health Forensic and Scientific Services,

    39 Kessels Rd, Coopers Plains, Queensland, Australia 4108

    Oral Biology

    COMMONWEALTH OF AUSTRALIA

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    behalf of, Griffith University, pursuant to Part VB of The Copyright Act 1968(The Act; a copy of the Act is available at SCALEPlus, the legal

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    The material in this communication may be subject to copyright under the

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    Information or excerpts from this material may be used for the purposes of

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    Do not remove this notice

    Learning GoalsLearning Goals

    On completion of this topic you should be able to describe

    the general plan of the lymphatic drainage of the headand neck.

    You should be able to describe the positions of all the

    major groups of lymph nodes.

    Learning GoalsLearning Goals

    You should be able to describe and demonstrate the

    ability to assess clinically the spread of infection in thehead and neck using the major lymph node groups.

    You should demonstrate an understanding of the role

    played by the lymphatic system in controlling and

    directing the spread of infection and certain neoplasia

    in the head and neck.

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    LymphaticsLymphatics

    The lymphatic system is concerned with the removal and

    return to the blood system of tissue fluid not reabsorbed

    into the blood capillaries during circulation, with the

    absorption of fat from the small intestine, and mostimportantly, with immunity.

    LymphaticsLymphatics

    It consists of lymphatic capillaries and vessels, lymph

    nodes, organs such as the thymus, spleen and bone

    marrow, and with masses of lymphatic tissue in the

    walls of the alimentary tract, together with circulatingcells.

    LymphaticsLymphatics

    In our discussion of the lymphatics in this session, we

    will restrict ourselves to a discussion of the structuralcomponents of the lymphatic system and the various

    groups of lymph nodes and lymphatic capillaries and

    vessels in the head and neck, and consider their

    importance in the spread of infection and in clinical

    diagnosis.

    Vascular SystemVascular System

    Recall that the blood vascular system is a body system

    that deals with two of the body's most importantfunctions: transport and protection.

    It comprises the blood system, the lymphatic system,

    and the interstitial fluid. Each of these is related to the

    other, and their functions are closely allied as a result.

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    Vascular SystemVascular System

    The blood system acts as the transport system for the

    body.

    The lymphatic system is the body's protective system.

    Interstitial fluid is the contact that each individual cell has

    with the fluid system of the body.

    Fluid MovementFluid Movement

    The heart acts as

    the fluid pump

    within the body.

    It pumps blood into

    arteries, andreceives blood from

    veins.

    http://www.mhhe.com/biosci/ap/dynamichuman2/content/gifs/0136B.gif

    Fluid MovementFluid Movement

    On the right side, blood is sent into the pulmonary circuit. The

    pulmonary artery carries deoxygenated blood to the lungs, and

    the pulmonary vein returns oxygenated blood to the left side of

    the heart.

    http://www.mhhe.com/biosci/ap/dynamichuman2/content/gifs

    /0140.gif

    Fluid MovementFluid Movement

    The left ventricle of the heart pumps blood into the systemic

    circuit, though which it flows eventually back to the right atrium

    before revisiting the pulmonary circuit again.

    http://www.mhhe.com/biosci/ap/dynamichuman2/content/gifs

    /0140.gif

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    Fluid MovementFluid Movement

    Blood leaving the heart initially

    flows through large arteries. As

    these arteries become more distant

    from the heart, they subdivide,

    becoming smaller vessels known

    as arterioles.

    Arteries and arterioles have

    significant amounts of smoothmuscle in their walls, and this helps

    maintain blood pressure, and

    absorbs some of the pumping force

    of the heart.http://www.lab.anhb.uwa.edu.au/mb140/CorePage

    s/Vascular/Vascular.htm

    Fluid MovementFluid Movement

    Finally blood flows into smaller

    vessels still, known as

    capillaries.

    Capillaries are incredibly

    numerous, but are small in

    cross-section, and are quitepermeable to a number of

    substances including fluid from

    the blood plasma.http://www.lab.anhb.uwa.edu.au/mb140/CorePage

    s/Vascular/Vascular.htm

    Fluid MovementFluid Movement

    Due to the blood pressure in the

    initial part of the capillary, some

    of the plasma is filtered throughthe vessel wall and emerges

    from the capillary.

    This is the source of the

    interstitial fluid, the fluid that lies

    between the cells of the body.

    http://www.chelationtherapyonline.com/articles/im

    ages/bloodvessels_4.gif

    Fluid MovementFluid Movement

    You may think of interstitial fluid as resulting in somerespects from the natural leakiness of the capillaries.

    Within the interstitial fluid, nutrients and gases are carried

    to every cell of the body, and waste products are

    removed.

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    Fluid MovementFluid Movement

    As the blood pressure falls

    along the length of the

    capillary, it becomes

    comparable with the

    osmotic force exerted by the

    concentration of large

    molecules remaining in thecapillary lumen that did not

    escape into the surrounding

    tissues. http://www.chelationtherapyonline.com/articles/images/bloodvessels_4.gif

    Fluid MovementFluid Movement

    As we move further

    along the capillary, and

    the blood pressure

    drops still further, the

    osmotic force begins to

    dominate, setting up an

    osmotic gradient thatfavours the return of the

    interstitial fluid back into

    the capillary.

    Van de Graff, K. Human Anatomy, Wm. C. Brown Iowa, 2 nd Ed. P

    532

    Fluid MovementFluid Movement

    Approximately 80% to 90% of interstitial fluid is reabsorbed

    back into the capillaries in this way.

    http://training.seer.cancer.gov/module_anatomy/unit8_2_lymph_compo.html

    Fluid MovementFluid Movement

    http://training.seer.cancer.gov/module_anatomy/unit8_2_lymph_compo.html

    The remainder would waterlog the tissues, however, if it were

    allowed to remain, so instead it is gathered up into small

    vessels known as lymphatic capillaries, and channelled into

    the lymphatic system.

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    Fluid MovementFluid Movement

    Here, it passes into

    lymphatic vessels, during

    its passage along which it

    will pass through lymph

    nodes.

    The lymph nodes play arole in controlling the

    spread of infection and in

    fighting it.

    Van de Graff, K. Human Anatomy, Wm. C. Brown Iowa, 2 nd

    Ed. P 532

    Fluid MovementFluid Movement

    Eventually, all this lymph

    fluid is returned to the

    blood system through two

    large lymphatic vessels,

    the right lymphatic duct

    and the thoracic duct,which drain into veins in

    the neck.

    From Grays Anatomy, Longman, London, 35 th Ed 1973p.

    727.

    Fluid MovementFluid Movement

    The remainder of the blood

    returns to the heart through

    larger vessels, venules,

    which lead to veins, and

    these, in turn, return to the

    heart.

    Van de Graff, K. Human Anatomy, Wm. C. Brown Iowa, 2 nd

    Ed. P 532

    Fluid MovementFluid Movement

    Now that we can see the broad relationship between the

    three types of fluid, blood, lymph and interstitial fluid, and

    how the interstitial fluid and lymph are formed, let us

    examine the components of the system more closely.

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    Lymphatic CapillariesLymphatic Capillaries

    Unlike the capillaries of the blood system, which bridge

    between the arterial part and the venous part of the

    circulation, there is no arterial part to the lymphatic

    system.

    It simply begins in the tissues, wherever excess tissue

    fluid collects from blood capillaries, as a system of blind

    lymphatic capillaries.

    Lymphatic CapillariesLymphatic Capillaries

    Lymphatic capillaries are

    tiny thin-walled vessels

    that begin as blind tubes

    in the spaces between

    cells in most tissues of

    the body except in

    cartilage and the central

    nervous system, the

    epidermis including the

    hair and nails, cornea of

    the eye, and also bone

    marrow.www.anatomy.dal.ca/html/Human%20Histology/DHD/Lab2/

    4_lh.JPG

    Lymphatic CapillariesLymphatic Capillaries

    Basically, anywhere that there is circulation, there are also

    lymphatic capillaries.

    They are not therefore found in the avascular tissues such as

    those we listed above.

    Tissue fluid in the brain and spinal cord drains into the

    cerebrospinal fluid through spaces around the blood vessels.

    Lymphatic CapillariesLymphatic Capillaries

    In structure, lymph

    capillaries are most

    similar to blood

    capillaries, but differ in

    some respects.

    www.anatomy.dal.ca/html/Human%20Histology/DHD/Lab2/

    4_lh.JPG

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    Lymphatic CapillariesLymphatic Capillaries

    Lymph capillaries are lined by

    endothelial cells like blood

    capillaries, but in lymphatic

    capillaries, the endothelial

    cells overlap each other.

    http://www.bmb.psu.edu/courses/bisci004a/immune/lympi

    ntak.jpg

    Lymphatic CapillariesLymphatic Capillaries

    This is important, because

    when pressure from the

    accumulating tissue fluid from

    outside the capillary pushes

    on its wall, the flap of

    endothelial cell beneath the

    overlap swings inwards to let

    the fluid into the vessel. http://www.jdaross.mcmail.com/images/lymphatic.gif

    Lymphatic CapillariesLymphatic Capillaries

    Once the fluid is in the lumen,

    then it cannot escape again,

    because it simply pushes this

    flap closed again and is

    prevented from getting backout.

    Because of this structure,

    lymphatic capillaries are more

    permeable than blood

    capillaries, and substances ofhttp://www.jdaross.mcmail.com/images/lympha

    tic.gif

    large molecular size, and even particles such as cell debris

    and micro-organisms can be accommodated.

    Lymphatic CapillariesLymphatic Capillaries

    They also have larger, more

    irregular lumens which are

    capable of holding larger

    particles in their contents.

    They are very hard to see in

    microscopic sections because

    they tend to collapse when

    they are empty.

    http://www.bmb.psu.edu/courses/bisci004a/immune/lympi

    ntak.jpg

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    Lymphatic CapillariesLymphatic Capillaries

    Lymphatic capillaries also

    possess valves which permit

    the lymphatic fluid to travel in

    one direction only.

    This is important, because it

    ensures that fluids andmaterials collected in a

    lymphatic capillary are

    directed through lymph nodes.http://www.jdaross.mcmail.com/images/lympha

    tic.gif

    Lymphatic CapillariesLymphatic Capillaries

    These lymphatic capillaries form networks that eventually join

    together to form larger trunks, which have a structure similar

    to veins, but are thinner with less-well defined tunic layers.

    Along these larger vessels lie lymph nodes.

    Lymph from most parts of the body is forced to pass through

    one or more lymph nodes on its way back to the venouscirculation, with the exception of the lymph from the thyroid

    gland and the oesophagus, which drains directly into the

    thoracic duct.

    Lymph VesselsLymph Vessels

    Eventually, lymph vessels drain into either the thoracic duct or

    the right lymphatic duct.

    All of the lymphatic vessels of the body drain into the thoracic

    duct except for those of the right side of the head, the right

    upper limb, and the right neck and the right side of the thorax.

    Lymph VesselsLymph Vessels

    The thoracic duct drains into the

    junction between the left internal

    jugular vein and the left subclavian

    vein.

    All the tissues of the right side ofthe head, the right upper limb, and

    the right neck and thorax drain into

    the right lymphatic duct which

    drains in turn into the junction

    between the right internal jugular

    vein and the right subclavian vein.

    From Grays Anatomy, Longman, London, 35 th Ed 1973p. 727

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    Lymph VesselsLymph Vessels

    Larger lymphatic vessels also possess valves, which once

    again forces the lymph to travel away from the tissues and

    towards the venous circulation in one direction only.

    Lymphatic NodulesLymphatic Nodules

    Throughout the loose connective tissues of the body, small

    nodules of lymphatic tissue can be found. These are smallish

    masses, perhaps 1 mm or so in diameter, and they occur

    particularly in the connective tissue beneath mucous

    membranes.

    Lymphatic NodulesLymphatic Nodules

    In the head and neck, they are particularly noticeable aroundthe posterior part of the oral and nasal cavities.

    Elsewhere in the body, we find them in the walls of the

    intestines, around the anus, and in relation to the urinary tract.

    Lymphatic NodulesLymphatic Nodules

    They are distributed strategically so as to protect underlyingtissues that may be at risk of penetration by microorganisms

    from the digestive, respiratory and urinary tubes, all of which

    have surfaces that lie outside the body, and which may

    therefore harbour dangerous bacteria and viruses.

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    Lymphatic NodulesLymphatic Nodules

    If you examine such a lymph nodule with a microscope, you

    notice that it is packed with lymphocytes, but unlike the lymph

    nodes, the lymph nodules do not connect to lymph vessels.

    An Atlas of Human Histology, Di Fiore M. Lea & Febiger, Philadelphia, 1st Edition 1961, p. 113.

    Lymphatic NodulesLymphatic Nodules

    Sometimes, observation with the microscope will reveal centres

    where many immature lymphocytes are busily developing in

    response to some immune challenge that requires cells that

    can respond to a specific agent.

    An Atlas of Human Histology, Di Fiore M. Lea & Febiger, Philadelphia, 1st Edition 1961, p. 113.

    Lymphatic NodulesLymphatic Nodules

    Such areas are known as germinal centres.

    An Atlas of Human Histology, Di Fiore M. Lea & Febiger, Philadelphia, 1st Edition 1961, p. 113.

    Lymphatic NodulesLymphatic Nodules

    While most lymph

    nodules are smallish

    and occur as solitary

    structures, in some

    areas they are found

    as large clusters.

    Some of these we are

    already familiar with,

    such as the tonsils.

    Copyright University of Queensland School of Dentistry

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    Lymphatic NodulesLymphatic Nodules

    Indeed, the tonsils form a kind of ring around the entry to the

    oropharynx and nasopharynx, made up of the single

    pharyngeal tonsil (adenoid), the two palatine tonsils, and the

    lingual tonsil.

    This ring is known as Waldeyer's Lymphatic Ring, after theworker who first described it.

    Lymph NodesLymph Nodes

    Lymph nodes are small,

    bean shaped masses of

    lymphatic tissue of

    varying size.

    http://www.acm.uiuc.edu/sigbio/project/updated-

    lymphatic/lymph7.html

    Lymph NodesLymph Nodes

    The node is enclosed in a

    strong fibroelastic

    capsule, and extensionsof this capsule run into

    the node, forming

    partitions that partially

    divide the node into

    several incomplete

    compartments.

    Van de Graff, K. Human Anatomy, Wm. C. Brown, Iowa, 2 nd

    Ed. P 534

    Lymph NodesLymph Nodes

    Lymph vessels that

    approach a lymphnode, carrying their

    one-way load of

    lymph, divide up into a

    number of branches.

    http://www.acm.uiuc.edu/sigbio/project/updated-

    lymphatic/lymph7.html

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    Lymph NodesLymph Nodes

    Lymph flowing in along

    these branches is

    directed to the outside

    of the node, and must

    flow through channels

    called lymphatic

    sinuses within the

    node to get to theoutgoing vessel in the

    region called the hilus

    of the node.

    http://www.jdaross.mcmail.com/lymphnode.htm

    Lymph NodesLymph Nodes

    These channels are

    lined with

    lymphocytes and

    macrophages.

    As it passes throughthe lymph node, the

    lymph is filtered past

    these cells.

    http://www.jdaross.mcmail.com/lymphnode.htm

    Lymph NodesLymph Nodes

    The lymph may contain debris including micro-organisms of

    varying types that have penetrated the body's defence

    barriers, phagocytic cells that may have been attracted tosuch a breach (some of which may either be alive or dead,

    and some of which may contain ingested microbes or other

    materials), damaged or worn-out tissue cells, cells from

    malignant tumours, or inhaled particles in nodes downstream

    from respiratory passages or the lungs.

    Lymph NodesLymph Nodes

    As these materials are exposed to the lymphocytes andmacrophages, their organic components are either

    phagocytosed by the macrophages or destroyed by antibodies

    made by the B-lymphocytes.

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    Lymph NodesLymph Nodes

    There are usually several lymph nodes between a region of

    tissue and the venous system. This means that material that

    was not filtered off and successfully dealt with in one lymph

    node passes on to the next and so on.

    By the time the lymph reaches the blood it has usually beencleaned of all impurities such as cell debris and foreign

    bodies.

    Lymph NodesLymph Nodes

    In some instances where phagocytation is incomplete the

    node may swell.

    You may well have experienced swollen cervical lymph nodes.

    These often accompany a sore throat due to streptococcal

    infection.

    Infections in almost any part of the body may result in swellingand tenderness of the lymph nodes associated with that part

    of the body.

    Lymph NodesLymph Nodes

    Activated T and B lymphocytes multiply in the lymph nodes,

    and T and B lymphocytes are added to the lymph as it flows

    through the sinuses.

    The lymph leaving the node therefore carries lymphocytes that

    will eventually pass into the blood.

    Antibodies produced by the B lymphocytes enter the lymph

    and the blood draining the node.

    Lymph NodesLymph Nodes

    Lymph nodes are therefore important to us clinically.

    If we know the route by which a body part is drained, and

    which groups of lymph nodes lie along the route taken by the

    vessels that drain it, then we can assess those nodes for

    swelling and hardness (induration) and tenderness to

    palpation.

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    Regional Lymph NodesRegional Lymph Nodes

    We learn about the regional lymph nodes in the head and

    neck so that we can assess them to determine the spread of

    infection, and in some cases, so we can ensure that we

    remove all those nodes that may be affected by a spreadingcancer.

    Regional Lymph NodesRegional Lymph Nodes

    We can divide the nodes of the head and neck into superficial

    groups and deep groups.

    The superficial groups tend to be more important to us

    clinically, because we can palpate them directly.

    Regional Lymph NodesRegional Lymph Nodes

    Superficial Groups:

    Deep Groups:

    Pericervical ri ng

    Nodes accompanying superficial neck veins

    Perivisceral ring

    Deep cervical chain

    Pericervical RingPericervical Ring

    This group is clinically important and comprises:

    Submental Group

    Submandibular Group

    Parotid or Pre-auricular Group

    Mastoid Group

    Occipital Group

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    Pericervical RingPericervical Ring

    These groups of

    nodes drain the

    surface tissues

    of the head and

    the face.

    From Grays Anatomy, Longman,

    London, 35th Ed 1973p. 729

    Pericervical RingPericervical Ring

    The drainage

    pattern is

    shown on this

    diagram.

    Pericervical RingPericervical Ring

    The scalp drains

    into all nodes, whilethe eyelids and

    cheeks drain into

    the parotid and

    submandibular

    groups.

    Pericervical RingPericervical Ring

    The external nose and

    the upper lip drain intothe submandibular

    group, while the lower

    lip drains into the

    submental and

    submandibular

    groups.

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    Pericervical RingPericervical Ring

    The floor of the mouth

    at the sides drains into

    the submandibular

    group and also to the

    deep cervical chain.

    The lateral parts of thelips drain into the

    submandibular group.

    Pericervical RingPericervical Ring

    The tip of the tongue, the

    central parts of the floor of

    the mouth and the lower lip

    drain bilaterally into the

    submental group.

    Anterior teeth as far back as

    the canines drain into the

    submandibular andsubmental groups, and

    premolar and molar teeth

    drain into the parotid group

    and the deep cervical chain.

    Superficial NeckSuperficial Neck

    The nodes accompanying

    superficial neck veins are

    also clinically important,

    since they are easily

    palpable in the clinic, and

    tell us about superficial

    infections and systemic

    infections.

    These lie in two chains

    which follow the anterior

    jugular vein and the

    external jugular vein

    respectively.

    Superficial NeckSuperficial Neck

    The nodes in the group

    following the external

    jugular vein are particularly

    easily palpated in the living

    individual because they lie

    superficially to thesternocleidomastoid

    muscle.

    You should take care to be

    sure you can recognize

    these as distinct from the

    nodes of the deep cervical

    chain.

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    Perivisceral RingPerivisceral Ring

    The most anterior group of these nodes changes its name as it

    ascends in the neck, according to the structures alongside

    which it lies at any particular level:

    pre-tracheal nodes

    pre-laryngeal nodes

    infrahyoid nodes

    These lie anteriorly in the neck, in front of the larynx and

    trachea.

    Perivisceral RingPerivisceral Ring

    The posterior group also changes its name in the same way.

    Thus, we have:

    retro-oesophageal nodes

    retro-pharyngeal nodes

    Perivisceral RingPerivisceral Ring

    The paratracheal group lies laterally alongside the trachea.

    The entire group surrounds the larynx, trachea and

    oesophagus, giving rise to its name, the perivisceral ring,

    since it surrounds the neck viscera.

    Deep Cervical ChainDeep Cervical Chain

    The deep cervical chain is difficult to

    palpate for most of its course since it

    lies deep to the sternocleidomastoid

    muscle, but at its upper and lower

    ends, it has two major nodes namedfor muscles close to which they lie.

    These are the jugulodigastric node

    (upper) and the jugulo-omohyoid

    node (lower).

    The other nodes in this chain are not

    named.

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    Deep Cervical ChainDeep Cervical Chain

    All of the lymph from the head and

    neck eventually drains into the deep

    cervical chain on both sides.

    Premolar and molar teeth drain into

    its upper nodes, as do the sides of

    the tongue and the floor of the mouth

    at the sides.

    The palate drains into the upper

    nodes, and the pericervical groups

    also drain into this chain.

    Deep Cervical ChainDeep Cervical Chain

    The deep cervical chain drains into

    the right lymphatic duct on the right

    side, and into the thoracic duct on the

    left.

    Learning GoalsLearning Goals

    On completion of this topic you should be able to describe

    the general plan of the lymphatic drainage of the headand neck.

    You should be able to describe the positions of all the

    major groups of lymph nodes.

    Learning GoalsLearning Goals

    You should be able to describe and demonstrate the

    ability to assess clinically the spread of infection in thehead and neck using the major lymph node groups.

    You should demonstrate an understanding of the role

    played by the lymphatic system in controlling and

    directing the spread of infection and certain neoplasia

    in the head and neck.

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    The End