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