Lymphatic and Immune System

Charles C. Cook, MD A & P

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ObjectivesList the functions of the lymphatic system.Trace the pathway of lymph starting at the lymph

capillary.Describe the characteristics of lymph capillaries.Compare and contrast lymph vessels and veins.Describe the location and function of lymph nodes.Describe the location & function of lymphatic

trunks.List the collecting ducts, their location, & the

individual areas of the body they drain.

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Identify the cisterna chyli’s location and the areas of the body from which it receives lymph.

List the functions of lymph.List the characteristics of lymph.Describe the mechanism by which lymph

is propelled.Define edema and how it may accumulate

after cancer surgery.

Objectives

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List the anatomical features and functions of lymph nodes.

Describe the major locations of lymph nodes.List major lymph structures and their location.

ThymusPharyngeal tonsils (adenoids)Palatine tonsilsLingual tonsilsSpleen

Function

Objectives

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Define the following terms.Immune systemPathogensInfectionImmunity

Nonspecific ImmunitySpecific Immunity

Autoimmunity

Objectives

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Functions of the Lymphatic System

Circulates body fluidTransports excess tissue fluid

Defends the bodyAbsorbs lipids

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Lymphatic VesselsLymphatic capillariesLymphatic vesselsLymph nodesLymphatic trunksCollecting ducts

Thoracic ductRight lymphatic duct

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Lymphatic Capillaries

ORIGINATE AS MICROSCOPIC CLOSED END TUBES - IN SPACES BETWEEN CELLS

More porousSimple squamous epithelium (endothelium)

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Lymphatic Vessels

FORMED FROM CAPSSIMILAR to VEINSVALVES gives beaded appearanceFollow veins

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Lymph Nodes

Structures located along the lymphatic pathways.

They contain large numbers of lymphocytes.

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Lymphatic Trunks

Collects lymph from the most proximal group of

each chain of nodes

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Lymphatic TrunksLumbarIntestinalBronchomediastinalSubclavianJugular

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Collecting ducts

Thoracic duct

Right lymphatic duct –

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Collecting DuctsThoracic Duct

Largest and l- o- n- g- e- r

Receives ¾ of body’s lymphDrains into left subclavian vein

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Cisterna Chyli

Dilated portion of the beginning of the

thoracic duct in the lumbar region

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Cisterna Chylireceives lymph from

Lower abdomenPelvis, &Lower limbs

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Collecting Ducts

Right Lymphatic DuctRight thorax and empties into the right subclavian vein

Drains Right side of head, neck and right arm

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Lymph

Clear, watery fluidFound inside lymphatic vessel

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Function of Lymph

Transports various foreign particles such as bacteria and viruses

Returns protein back to blood as well as excess tissue fluids

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Movement of Lymph

Skeletal muscle contraction

PressureValves

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MILKING ACTION

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How can a massage affect Lymph flow?

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Movement of Lymph

Contraction of diaphragm

Pressure changes33

Edema

Accumulation of fluid in the tissue

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Can a patient develop edema after an

amputation of an extremity?

Can this be prevented?37

Structure of *LNsBean shaped Vary in size (usually about 1 in.)

Afferent----EntranceEfferent----Exits at the Hilium

*LN denotes lymph nodes throughout presentation 38

Lymph NodesMore afferent vessels than efferent

covered by fibrous capsule

contain dense masses of lymphocytes and macrophages (nodules)

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LYMPH NODE

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MAJOR LOCATIONS OF LYMPH NODES

CERVICAL REGIONAXILLARY REGIONINGUINAL REGIONPELVIC CAVITYABDOMINAL CAVITYTHORACIC CAVITY

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Functions of LNs

Produces lymphocytesFilters interstitial compartment

Contains macrophages

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ThymusLocated within the superior mediastinum. Aprox. 40 gms

First source of lymphocytes before birth

Development of T-CellsThymosin

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TonsilsProtects mouth

Pharyngeal tonsil (Adenoid)

Palatine tonsilsLingual tonsils

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Spleen

Largest Lymphatic organFilters blood not lymphProduction of B-CellsNormal volume ---- 350 ml

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SpleenDefenseHematopoiesisRBC and platelet destruction

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SpleenLocation

Left hypochondriac region

Below diaphragmAbove left kidneyBehind fundus of stomach

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The SpleenWhy is the spleen considered a lymphatic organ although it does not filters lymph?

Have you ever experienced pain in your side while you were running?

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Immunity TermsImmune systemPathogensInfectionImmunity

Nonspecific ImmunitySpecific Immunity

Autoimmunity

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Immune system

Body’s defense against disease

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Pathogens

Microorganism that causes disease

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Infection

CAUSED BY THE DISEASE - CAUSING AGENTS

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Immunity

THE BODY’S ABILITY TO RESIST PATHOGENS

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AutoimmunityAttack launched due to failure to distinguish from self and non-self substances

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Questions??

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Nonspecific ImmunityGeneral Protection

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Species Resistant

Resistance of a disease of one species compared to another

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Mechanical Barriers(Physical barriers)

1st Line of defenseSkin Mucous membrane

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Chemical barriers

2nd Line of defensePepsinLysozymeVaginal secretions

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Interferon

Released by virus-infected cells to stop division of

malignant cells

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InflammationIs there anything good about inflammation?

Required for healing

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Inflammation(Nonspecific)

Due to damaged tissue cells

Response to tissue invasion

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InflammationRedness PainHeatSwelling

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Stages of Inflammation

1.Vasodilatation2.Phagocyte migration3.Repair

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PhagocytosisNeutrophils (Microphages)

Monocytes (Macrophages)

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Specific ImmunitySpecific Protection

AntigensInventory of self substancesDevelop receptors for non-self Foreign proteins are recognized

Immune response80

Specific ImmunityHaptens

Smaller molecules that combine with larger

ones to ignite an immune response

IE… Penicillin and lipid toxin in poison ivy

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Specific Immunity

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LymphocytesOriginates from stem

cells in red bone marrow

Immature T-cellsImmature B-cells

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All Lymphocytes

Accounts for 20-30 % of the circulating WBC population

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Functions of Lymphocytes

T-CellsCell-mediated immunitySecrete lymphotoxins - kills antigen-bearing cells

Secrete lymphokines (Cytokines) - stimulate the immune activity of other cells

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T-CellsCell-mediated immunity

Attacks:

Parasites, fungi, and bacteriaSome cancer cellsForeign tissue transplants

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Functions of Lymphocytes

B-CellsResponsible for antibody-mediated immunity

Mature in plasma cellsPlasma cells--- synthesize and secrete antibodies

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B (bone marrow - derived) Cells Accounts for 10-15 % of the circulating lymphocytes

Can differentiate into Plasma cells

Plasma cells Antibodies

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B-Cells Antibody-mediated immunity

Attacks:

Antigens dissolved in body fluids

Extracellular pathogens, primarily bacteria

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Types of Antibodies Immunoglobin G (IgG) – occurs in plasma and tissue fluid (Placenta)

Immunoglobin A (IgA) – found in secretions of exocrine glands (Breast milk)

Immunoglobin M (IgM) – develops in blood plasma

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Actions of Antibodies

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Complement Activation Normally inactive Becomes active when antibody combines w/ complement

Actions: Inflammation, lysis, and phagocytosis

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Precipitation – antigens become insoluble

Lysis- ruptures membraneAgglutination - Clumping of antigens

Neutralization – covers toxic portions

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Immune ResponsesPrimary immune

responseResponse of B & T cells after 1st exposure

Memory cells

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Immune ResponsesSecondary immune

response

Reaction time is faster due to memory cells

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Types Of

Immunity

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NATURALLY ACQUIRED ACTIVE IMMUNITY

NON-DELIBERATE EXPOSURE TO A

PATHOGEN

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PASSAGE OF ANTIBODIES FROM

THE MOTHER TO THE FETUS

NATURALLY ACQUIRED PASSIVE IMMUNITY

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ARTIFICIALLY ACQUIRED ACTIVE IMMUNITY

DELIBERATE INJECTION OF PATHOGEN

(Vaccination)IE…FLU Shot

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ARTIFICIALLY ACQUIRED PASSIVE IMMUNITY

INJECTION OF ANTIBODIESShort Term

IE…Gamma Globulin / HEP A

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Given the antibodyIE. Flu ShotIE. IgA, GChicken Pox

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Types Of Allergic

Reactions108

ALLERGIC REACTION

EXAGGERATED IMMUNE RESPONSE

(ALLERGEN)Normally doesn’t occur

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Allergic ReactionsDelayed-reaction allergy

Immediate-reaction allergy

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DELAYED

AFFECT ANYONEREPEATED/PROLONGED SKIN EXPOSURE

T-CELL ACTIVATEDAPPROX: 48HRS REACTIONPoison Ivy 111

IMMEDIATE REACTION

OCCURS IN MINUTESINDIVIDUALS GENETICALLY PREDISPOSED

B-CELL ACTIVATEDRELEASE OF HISTAMINESINFLAMMATORY RESPONSE

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It’s A Wrap

Questions??

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