Transcript Blood and L..

Blood and
Lymphatic
Systems
Pbp Summer 2014
Nikeshia Dunkelly-Allen
[email protected]
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Blood System
Overview
• Blood transports oxygen and nutrients to body cells
• Blood removes carbon dioxide and other waste products
from body cells for elimination
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Composition of
Blood
• Plasma
• 90 percent water = liquid portion of blood
• Transports cellular elements of blood throughout circulatory
system
• Remaining portion = solutes
• Electrolytes, proteins, fats, glucose, bilirubin, and gases
• Most abundant solutes are plasma proteins: albumins, globulins,
and fibrinogen
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Composition of
Blood
• Solid components
• Formed elements = cells + cell fragments
• Erythrocytes, leukocytes, thrombocytes
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Plasma Proteins
• Albumins
• Constitute about 60 percent of the plasma proteins
• Help maintain normal blood volume and blood pressure
• Help to maintain balance between fluid in the blood and
fluid in the interstitial tissues
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Plasma Proteins
• Globulins
• Constitute approximately 36 percent of plasma proteins
• Alpha and beta globulins transport lipids (fats) and fat-soluble
vitamins in blood
• Gamma globulins are antibodies and function in immunity
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Plasma Proteins
• Fibrinogen
• Constitutes approximately 4 percent of plasma proteins
• Largest of plasma proteins
• Essential in process of blood clotting
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Blood Cells
• Erythrocytes
• Known as red blood cells (RBC)
• Tiny biconcave-shaped disks
• Thinner in center than around edges
• No nucleus in mature red blood cell
• Average life span = approximately 120 days
• Main component = hemoglobin
• Primary function = transport oxygen to cells of body
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Blood Cells
• Leukocytes
• Known as white blood cells (WBC)
• Larger than erythrocytes, but fewer in number
• Mature WBC has a nucleus; does not have hemoglobin
• Two categories = granulocytes + agranulocytes
• Granulocytes have granules in their cytoplasm
• Agranulocytes have no granules in their cytoplasm
• Five different types of leukocytes within the categories
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Blood Cells
Granulocytes
• Neutrophils
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Constitute approximately 60-70 percent of all WBCs
Have multi-lobed nuclei
Phagocytic in nature
Do not absorb acid or base dye well
• Remain fairly neutral color
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Granulocytes
• Eosinophils
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Constitute approximately 2-4 percent of all WBCs
Have a nucleus with two lobes
Increase in number in response to allergic reactions
Stain a red, rosy color with an acid dye
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Granulocytes
• Basophils
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Constitute less than 1 percent of all WBCs
Have a nucleus with two lobes
Secrete histamine during allergic reactions
Secrete heparin – a natural anticoagulant
Stain a dark blue with a base dye
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Blood Cells
Agranulocytes
• Monocytes
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Constitute approximately 3-8 percent of all WBCs
Largest of all white blood cells
Have a kidney bean-shaped nucleus
Phagocytic in nature
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Agranulocytes
• Lymphocytes
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Constitute approximately 20-25 percent of all WBCs
Have a large spherical-shaped nucleus
Play important role in immune process
Some lymphocytes are phagocytic
Other lymphocytes produce antibodies
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Cell Fragments
• Thrombocytes
• Small, disc-shaped fragments of very large cells called
megakaryocytes
• Also known as platelets
• Contain no hemoglobin
• Essential for normal clotting of blood
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Blood Clotting
• Clotting of blood = coagulation
• Injury to blood vessel creates roughened area in vessel
• Platelets come in contact with rough spot and disintegrate
• Release substance called thromboplastin
• Thromboplastin converts prothrombin into thrombin
• In presence of calcium ions and other clotting factors
• Thrombin converts fibrinogen into fibrin
• Fibrin threads form a mesh that forms the clot
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PATHOLOGICAL
CONDITIONS
The Blood
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Malaria
Plasmodium vivax is a protozoal parasite and a human pathogen. The most
frequent and widely distributed cause of recurring (tertian) malaria, P. vivax is
one of four species of malarial parasite that commonly infect humans. It is
less virulent than Plasmodium falciparum, which is the deadliest of the four,
and seldom fatal. P. vivax is carried by the female Anopheles mosquito, since it
is the only sex of the species that bites.
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Sickle Cell Anemia
• Chronic hereditary form of hemolytic anemia in which RBCs
become crescent-shaped in presence of low oxygen
concentration
• Crescent-shaped RBCs clump together forming thromboses which
occlude small blood vessels, causing much pain for the individual
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Sickle-cell
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Hemophilia
• Hemophilia is a rare genetic bleeding disorder caused by a
shortage of certain clotting factors. Blood clotting factors
are needed to help stop bleeding after a cut or injury to
prevent spontaneous bleeding. Approximately 20,000
people in the United States suffer from hemophilia.
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Leukemia
• Leukemia is a cancer of the blood or bone marrow
characterized by an abnormal proliferation of blood
cells, usually leukocytes (white blood cells). Leukemia
is a broad term covering a spectrum of diseases. In
turn, it is part of the even broader group of diseases
called hematological neoplasms.
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Thalassaemia
Thalassaemia is an inherited autosomal recessive blood
disease. In thalassemia, the genetic defect results in
reduced rate of synthesis of one of the globin chains that
make up hemoglobin. Reduced synthesis of one of the
globin chains can cause the formation of abnormal
hemoglobin molecules, thus causing anemia, the
characteristic presenting symptom of the thalassemias.
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Blood doping
• Blood doping is the practice of boosting the number of
red blood cells (RBCs) in the bloodstream in order to
enhance athletic performance. Because they carry
oxygen from the lungs to the muscles, more RBCs in
the blood can improve an athlete’s aerobic capacity
(VO2 max) and endurance.
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Lymphatic
system
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Lymphatic System
Overview
• Lymphatic system functions to produce antibodies and
lymphocytes important to immunity
• Lymphatic system also functions to maintain a balance of
fluid in the internal environment
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Lymphatic System
Overview
• Lymphatic system
• Lymph fluid
• Stems from the blood and tissue fluid
• Lymph vessels
• Similar to blood vessels – designed to return tissue fluid to
bloodstream
• Lymph nodes
• Located along path of collecting vessels
• Lymphatic organs
• Thymus, spleen, and tonsils
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Lymphatic System
Overview
• How lymph vessels differ from blood vessels
• Lymph vessels do not form a closed circuit as does the
cardiovascular system
• Lymph vessels originate in intercellular spaces of soft tissues of
the body
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Lymphatic System
Overview
• Lymphatic system is an important part of the immune
system
• Immune system consists of:
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Bone marrow
Thymus
Lymphoid tissues
Lymph nodes
Spleen
Lymphatic vessels
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Lymph Vessels
• Lymph capillaries
• Smallest lymphatic vessels
• Originate in tissue spaces as blind-ended sacs
• Capillaries pick up accumulated interstitial fluid and return it
to the blood
• Fluid inside the lymphatic vessels is known as lymph
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Lymph Vessels
• Lymph vessels
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Larger than capillaries
Receive lymph from lymphatic capillaries
Valves prevent backward flow of fluid
Transport fluid in only one direction
• Away from the tissues toward the thoracic cavity
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Lymph Vessels
• Lymphatic ducts
• Only points of entry of lymph into blood vessels of body
• Right lymphatic duct
• Receives lymph drainage from right side of head and neck
• Also receives lymph drainage from right upper extremity, and right
side of chest
• Empties into right subclavian vein
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Lymph Vessels
• Lymphatic ducts
• Thoracic duct
• Receives lymph drainage from remaining regions of the body
• Empties into left subclavian vein
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Lymph Nodes
• Collections of lymphatic tissue
• Also called lymph glands
• Located at intervals along course of lymphatic system
vessels
• Lymph passes through stationary lymph nodes
• Old, dead cells and bacteria present in lymph are filtered out
• Macrophages engulf and destroy any bacteria present
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Axillary lymph nodes
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Thymus
• Located in mediastinum
• Secretes thymosin – stimulates red bone marrow to produce
T lymphocytes
• T- cells important in immune response
• T-cells mature in the thymus
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Spleen
• Located in upper left quadrant of abdomen: just below
diaphragm, behind stomach
• Largest lymphatic organ in the body
• Plays an important role in the immune response
• Filters blood
• Macrophages of spleen remove pathogens from circulating
blood
• Macrophages also remove old red blood cells from circulation
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Tonsils
• Masses of lymphatic tissue
• Located in protective ring, just under the mucous
membrane
• Surround the mouth and back of the throat
• Serve as first line of defense from the external
environment
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Tonsils
• Three groups
• Pharyngeal tonsils or adenoids
• Located near opening of the nasal cavity into pharynx (throat)
• Palatine tonsils
• Located on each side of the throat, near opening or oral cavity into
pharynx
• Commonly known as ‘the tonsils’
• Lingual tonsils
• Located near the base of the tongue
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Immunity
• Natural
• Immunity with which we are born; genetic
• Acquired
• Body has developed ability to defend itself against a specific
agent
• Can occur as result of having had the particular disease
• Can be result of having received immunizations against a disease
• Can be passive acquired immunity or active acquired immunity
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Immunity
• Passive Acquired Immunity
• Acquired artificially by injecting antibodies into a
person’s body
• Protects person from a specific disease
• Short-lived immunity – lasts only a few weeks
• Example: gamma globulin
• Given to individuals exposed to viruses such as measles and
infectious hepatitis
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Immunity
• Active Acquired Immunity
• Acquired naturally as result of having had a disease
• Acquired artificially by being inoculated with a vaccine,
antigen, or toxoid
• Immunization = process of creating immunity to a specific
disease
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Immune Reaction
• Immune reaction = Immune response
• Defense mechanism of the body
• Produces antibodies to destroy invading antigens and
malignancies
• Humoral immune response
• B lymphocytes come in contact with specific invading
antigens
• Produce antibodies known as immunoglobulins
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Immune Reaction
• Cell-mediated immune response
• T lymphocytes come in contact with specific invading
antigens
• T lymphocytes multiply rapidly and engulf and digest the
antigen
• Multiplication of cells produces memory cells
• Memory cells provide the body with resistance
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Hypersensitivity
• Abnormal condition characterized by an excessive
reaction to a particular stimulus
• Body’s immune system fails to protect itself against
foreign material
• Allergic reaction is triggered by an allergen
• Examples of allergens:
• Ingested foods, penicillin and other antibiotics, grass,
ragweed pollen and bee or wasp stings
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Hypersensitivity
• Hypersensitive reactions
• Local reaction
• Occurs at the site where treatment or medication was
administered
• Systemic reaction
• Evidenced by generalized body symptoms such as runny nose,
itchy eyes, hives, and rashes
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Hypersensitivity
• Hypersensitive reactions
• Anaphylactic shock
• Also known as anaphylaxis
• Antigen-antibody reaction stimulates a massive secretion of
histamine
• Example causes: insect stings, contrast media containing iodide,
aspirin, antitoxins prepared with animal serum, allergens used in
testing
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PATHOLOGICAL
CONDITIONS
Lymphatic System
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Acquired Immunodeficiency
Syndrome (AIDS)
• Clinical conditions that destroy the body’s immune system
in the last or final phase of a human immunodeficiency virus
(HIV) infection, which primarily damages helper T cell
lymphocytes with CD4 receptors
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Hypersensitivity
• Tissue damage resulting from exaggerated immune responses
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IgE-mediated-Type I hypersensitivity response
Cytoxic-Type II hypersensitivity reaction
Immune complex-mediated-Type III sensitivity response
Delayed-Type IV hypersensitivity responses
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Sources
• Thomas Delmar Learning
• Dr. Aziz Fall 2013 Lecture
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