LYMPHATIC SYSTEMST120: Concorde Career College

Lymphatic SystemObjectives: Define the term lymph. Describe the functions of the lymphatic

system. List and identify the structures of the

lymphatic system and describe the function of each.

Identify the origin of lymph.

Lymphatic SystemObjectives:

Trace the flow of lymph through the body.

Describe the immune system and describe the immune response.

Describe the mechanism by which the immune system helps to maintain homeostasis.

Lymphatic SystemObjectives:

Describe common diseases, disorders, and conditions of the lymphatic system including signs and symptoms, diagnosis, and available treatment options.

Demonstrate knowledge of medical terminology related to the lymphatic system verbally and in the written form.

Lymphatic SystemFunctions of the Lymphatic System

Removal of impurities

Lymphocyte processing

Lymphatic System The lymphatic system parallels

(same direction)the circulatory system

Lymph vessels return tissue fluid to the blood & protect the body against foreign material

The lymphatic system includes: Lymph fluid Lymph vessels Lymph nodes Spleen Thymus And tonsils

Lymph FluidLymph is the tissue fluid that enters and travels through the lymphatic vessels

Plasma flows out of blood capillaries into tissue spaces (interstitial fluid) – AKA Tissue fluid

Plasma diffuses out of the capillaries faster than it is reabsorbed, the remaining interstitial fluid is returned to the blood through the lymphatic system

Lymphatic Capillaries

Lymphatic Capillaries - Carry lymph and resemble blood capillaries

Lacteals - Specialized lymphatic capillaries that carry chyle

Lymph Vessels Vessels of the lymphatic system start with the

smallest blind (dead-ended) lymph capillaries The walls of the lymphatic capillaries are a

thin walled, single layer of loosely fit squamous epithelial cells making them highly permeable

Lymphatic capillaries join larger lymphatic arterioles that then join lymphatic arteries

Lymphatic vessels like the veins of the circulatory system have valves

Lymph Flow

Lymphatic System

Relationship of Lymphatic Vessels

to Circulatory System

Thoracic Duct Lymph returns to the blood flow through the

thoracic duct and the left subclavian vein Lymph from the lower body returns through the

thoracic duct Cisterna chyli – dilation at the beginning of the

thoracic duct (pouch-like structure) Lymph from a portion of the upper body also

empties into the thoracic duct superior to the cisterna chyli

Lymph from the upper left quadrant empties into the subclavian vein

Two terminal vessels include: Right Lymphatic duct & thoracic duct

Lymphahtic Drainage

Lacteal Found in the villi of the small intestine Responsible for absorbing fat-soluble

nutrients (fatty acids and vit. A,D,E & K) Fats are absorbed by the lacteals as

chylomicron Chylomicron: combination of fatty acids

and glycerol to form triglycerides

Lacteal

Lymph nodes and nodules Lymph Node: small ball shaped organs of the lymphatic system Lymph Nodules: groups of lymph cells located beneath the

epithelial layer of mucus membranes (ex. Respiratory tract and digestive tract) Peyer’s patches: lymphatic nodules of the ileum

Filters pathogens and foreign material before returning to blood Monitor the level of body fluid Hematopoietic function – produce lymphocytes, macrophages,

and monocytes Located throughout the body

Cervical Axillary Inguinal

Regional Lymph Nodes

Lymph node

HilusAfferent vessels x4 pg.261 A&PEfferent vessels x1Capsule Germinal centers SinusesTrabecula

Tonsils Palatine Tonsils (throat) – located at

each side of the oropharynx

Pharyngeal (Adenoids) – located on the posterior wall of the nasopharynx

Lingual Tonsils – located at the base of the tongue

Tonsils

Lymphedema Abnormal accumulation of fluid in

interstitial spaces Causes:

Obstruction of a lymphatic vessel (tumors, inflammation)

Increased capillary BP Abnormal uptake of fluid by the lymphatic

capillaries due to trauma or surgical wound (often seen after mastectomy)

Lymphedema

Lymphedema

Terms Lymphadenitis: inflammation of lymph

node/vessels Metastasis: is the spread of a disease

from one organ or part to another non-adjacent organ or part, causing a new cancer site

Lymphadenopathy: Any disease that usually involves the lymph glands

Sentinel Lymph Node Biopsy Method developed to determine if breast cancer has spread to lymph

ducts or nodes in the axilla Prevents the patient from having to undergo a lymph node dissection Sentinel Node: first node the breast drains to

Nuclear Medicine A radioactive dye is injected into the area where the tumor is located

as well as around the areola Hours later photos will reveal the pathway used to exit the breast,

this will reveal the sentinel node OR

Surgeon injects a blue dye into the breast that assists in visual of the nodes

Small incision is made in the axilla A special probe picks up signals form the radioactive dye and gets

“excited” when over an affected node All blue and radioactive nodes are removed

Spleen Highly vascular and friable (easily

crumbled/delicate) Located behind the stomach Contains lymphoid nodules (white pulp) Filters blood (red pulp) cleans out foreign

materials/microorganisms Stores blood (approximately 200 ml) aids in

maintenance of BP during severe hemorrhage Hematopoietic function: lymphocytes, monocytes,

leukocytes, fixed plasma cells In a fetus the spleen produces erethrocytes

Spleen

HilusSplenic artery Splenic vein

Spleen cont. #1 organ injured in MVA’s (motor vehicle

accidents) despite being protected by the lower ribs

Splenectomy: surgical removal of the Spleen

Lymphatic SystemReticuloendothelial System

Responsible for destruction of obsolete RBCs, bacteria, cancer cells, and other potentially harmful foreign substances.

Utilizes monocytes distributed throughout the body such as Kupffer’s cells located in the liver

Thymus Located in the mediastinum Composed of two lateral lobes bound by

a connective tissue capsule Proper function dependent on thymosin Produces T-cells important in cell

mediated immunity

Thymus

Lymphatic SystemLymphatic and Immune

Systems Thymus Bone marrow Spleen Tonsils Lymph nodes Lymph capillaries Lymph vessels Lymphocytes Lymph

Lymphatic SystemImmunologic Defenses

Provide the body with general defenses against disease. Nonspecific Defenses Specific Defenses

Lymphatic SystemNonspecific Defenses

Chemical and Mechanical Barriers Phagocytosis Natural Killer Cells Inflammation Fever Interferon

Lymphatic SystemOccurrence of Infection

Not every exposure to a pathogen results in infection. Portal of Entry Virulence

Toxins Dose Predisposition

Lymphatic SystemBarriers Against Infection

Chemical Body secretions

Mechanical Skin Mucous membranes Cilia

First Line of Defense

Our first line of defense against microbes include: Skin Mucous membranes Secretions

Skin Unbroken skin prevents microbes from

entering the body (keratin) Broken skin such as Burns, Cuts,

Scratches open the doors for an invasion of microbes such as Staphylococcus aureus

Sweat glands and Sebaceous gland secrete acids that kill or inhibit the growth of bacteria on the skin

Mucous Membranes Line tracts open to the exterior of the body

(respiratory, digestive, urinary) Goblet cells secrete mucous to line the

membranes and “catch” microbes Cilia catch and pass debris up to the pharynx to

be expelled

Glands in the stomach produce highly acidic gastric juice that kills most bacteria Helicobacter Pylori is an exception… can cause

stomach and duodenal ulcers

Second Line of Defense If pathogens penetrate the 1st line of defense

they will encounter the body’s 2nd line of defense Circulatory and chemical defenses

Circulatory Defenses: Phagocytes Complement proteins Iron Fever Inflammatory response Interferons

Phagocytes Leukocytes responsible for phagocytosis Phagocytosis: the process of surrounding and ingesting

another microbe

Granulocytes Neutrophils – motile and effective phagocytes Eosinophils – attach to parasites and secrete peroxide ions

which kill them. Play a larger phagocytic role during allergic response

Basophils Agranulocytes

Monocytes – enter body tissues and mature into stationary macrophages or travel through blood to infection site (wandering macrophages)

Kupffer cells (liver), microglia (brain) Lymphocytes – are not phagocytes but are important in the

immune response

Phagocytosis Chemotaxis – chemicals attract phagocytes to

injured tissues or bacteria Adherence – antibody molecules secrete a serum

protein that can coat a bacterial cell and promote attachment (opsonization)

Ingestion – phagocyte surrounds the microbe Pseudopods: “false feet” that extent to cover a microbe The resulting sac is called a Phagosome

Digestion – phagosome is moved into the cytoplasm (phagolysosome) and enzymes (from the lysosomes) destroy the bacteria Degranulation – digestion process

Complement proteins Group of 25-30 serum proteins found in

blood plasma Circulate inactive until needed in the

antibody-antigen reaction Activated Proteins: increase

inflammatory response, assist in lysis of antigen, attracts phagocytes

Complement cascade: sequence of proteins “bore” holes into bacteria causing an accumulation of fluid that eventually ruptures the cell

Iron Virulence of bacteria increases when free

iron is present Leukocytes: produce interleukin-1 (IL-

1), stimulates the liver to store iron depriving bacteria of necessary free iron

Inflammatory response Inflammation is a beneficial and necessary

response to injury The four signs of inflammation include:

Pain Heat Redness Swelling

Three stages of inflammation include: Vasodilatation Phagocyte migration Tissue repair

Inflammatory Response Vasodilation: Increased blood flow to

area and increased permeability of blood vessels

Histamine, kinins, and prostaglandins: chemicals released by damaged tissues responsible for vasodilatation

Fever An abnormally elevated body

temperature (controlled by hypothalamus)

Systemic response frequently caused by viral or bacterial invasion

Symptoms include heat, shivering and increased metabolism rate

Vasodilatation and sweating signify the temperature falling “ fever breaking”

Interferons- produced by T-cells Released to protect other cells by interferring with the

ability of the virus to reproduce as it moves from cell to cell

Proteins produced by leukocytes, T-lymphocytes, and fibroblasts in response to infection “interfere with viral replication”

Proteins enter surrounding cells and inhibit the synthesis of proteins needed by invading viruses for multiplication

They interfere with viral replicationPg. 269 A&P

Third line of Defense Immune response: lymphocytes

secrete antibodies that attach to microbes and inhibit or destroy them -- Called humoral antibodies

Formation of antibodies is stimulated by the presence of specific pathogens

Effective circulating antibodies gives us our immunity

Acquired Immunity Active acquired immunity:Immunity that develops after a person has had a disease

Natural – individual has an infection and produces antibodies

Artificial – vaccinations Attenuation: process of weakening a pathogen

Passive acquired immunity Natural – antibodies pass through the placenta or in

colostrum Artificial – antiserum (immune individual > susceptible

individual) Pasteur – rabies vaccine Sabin – polio vaccine

Lymphatic SystemSpecific Defenses

Immunity Final defense against disease Inborn (Passive) Acquired

Natural (Active or Passive) Artificial (Active)

Lymphatic SystemInborn Immunity

Species Racial Individual

Lymphatic SystemAcquired Immunity

Develops throughout the lifespan May occur naturally May be induced

Lymphatic SystemNatural Acquired Immunity

Active Contraction of the disease

Antibodies protect from recurrence May be long term or life long

Passive Mother to fetus via placenta Mother to infant via breast milk May last six months or slightly longer

Lymphatic SystemArtificial Acquired Immunity

Immunization Vaccines

Live Weakened (attenuated) Dead Toxoid Recombinant DNA May be long term or life long

Humoral Immunity Pg. 272 A&P

Cell-mediated Immunity Pg. 272 A&P

Antigens

Any substance that the body regards as foreign and stimulates the production of

antibodies aka is immunogenic

Antibodies – A disease fighting protein created by the immune system in response to the presence of that specific antigen

Immunoglobulins produced by B-lymphocytes

Bind to receptor site of specific antigen B-lymphocytes mature into:

Plasma cells – produce antibodies in response to an antigen (secretes them into blood)

Memory cells – produces antibodies quickly when the body is exposed to the same antigen again

Agammaglobulinemia: inability to produce antibodies (have no gammaglobulin)

T-cells: Involved in cell-mediated immune response Lymphoid stem cells that migrate to the thymus Cytotoxic T cell: Helper T cells: Memory T cell: Natural killer cell:

B-cells: Function in Humoral immunity pg. 272 A&P

Organ Transplants Tissue Rejection: cells of the recipient

do not recognize the tissue of the donor as self and attack/destroy the transplanted tissue

To minimize chance of rejection recipients and donors tissue should be antigenically similar. Close family members are ideal donors

Immunosuppressive drugs: suppresses recipients formation of antibodies/suppress the immune system

Terms

Isograft: genetically identical twin

Allograft: close family member

Xenograft: different species, Pig

Anaphylactic Reaction Anaphylaxis: severe allergic reaction that can be

life-threatening Signs/Symptoms:

Itching, swelling, difficulty breathing, hives, urticaria Severe difficulty breathing, laryngeal edema,

bronchospasm Treatment:

Epinephrine – bronchodilation, decrease laryngeal spasm, ^BP

Steroid – inhibit reaction Levoped (vasopressor) - ^BP Ringer’s Lactate – Fluids Box13-4

Latex Allergy Many items used in the OR contain latex,

daily exposure can cause a latex-sensitivity Latex allergic patients should be scheduled

as the first case of the day in an OR so there is not latex dust in the room form previous surgeries

Examples of latex in the OR Tape, elastic bandages, electrode pads, gloves,

tourniquets, endotracheal tubes,……….Box 13-3

AIDS Acquired immunodeficiency syndrome (AIDS) Human immunodeficiency virus (HIV) has the most

obvious effect in certain types of T-cells – virus that causes AIDS

Characteristics: Vulnerability to opportunistic infections Major decrease in T-lymphocytes Kaposi’s Sarcoma

Transmission: Sexual contact “dirty” hypodermic needles mother > fetus Blood transfusion

Hemolytic Transfusion Reaction Occurs after a patient receives a

transfusion of mismatched blood

Agglutination: clustering and destruction of RBC’s

Box 13-5

Autoimmunity Autoimmune disorder: the bodies

immune system regards normal body tissues as foreign. Can not distinguish self from non-self Rheumatoid arthritis Ulcerative colitis MS

Box 13-6