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  • 7/27/2019 Lymphatics Condensed Grayscale Slides


    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


    Copyright Regulations 1968


    This material has been reproduced and communicated to you by, or on

    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

    information retrieval system owned by the Australian Attorney Generals

    Department, at

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

    Act. Any further reproduction or communication of this material by you maybe the subject of Copyright Protection under the Act.

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

    private study, research, criticism or review as permitted under the Act, and

    may only be reproduced as permitted under the Act.

    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.

  • 7/27/2019 Lymphatics Condensed Grayscale Slides



    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.


    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.


    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


    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.

  • 7/27/2019 Lymphatics Condensed Grayscale Slides


    Vascular SystemVascular System

    The blood system acts as the transport system for the


    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


    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.


    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.


  • 7/27/2019 Lymphatics Condensed Grayscale Slides


    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.


    Fluid MovementFluid Movement

    Finally blood flows into smaller

    vessels still, known as


    Capillaries are incredibly

    numerous, but are small in

    cross-section, and are quitepermeable to a number of

    substances including fluid from

    the blood plasma.


    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.


    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


  • 7/27/2019 Lymphatics Condensed Grayscale Slides


    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


    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


    Fluid MovementFluid Movement

    Approximately 80% to 90% of interstitial fluid is reabsorbed

    back into the capillaries in this way.

    Fluid MovementFluid Movement

    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.

  • 7/27/2019 Lymphatics Condensed Grayscale Slides


    Fluid MovementFluid Movement

    Here, it passes into

    lymphatic vessels, during

    its passage along which it

    will pass through lymph


    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.


    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


    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.

  • 7/27/2019 Lymphatics Condensed Grayscale Slides


    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


    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