Transcript Blood presentation

Blood
• Cells in the body are fixed within tissues and
must have nutrients and oxygen brought to them
and waste removed.
• The blood is classified as a fluid matrix
connective tissue
– The cells and cell fragments are the formed
elements and the matrix of the blood is fluid
(plasma).
– Formed elements make up about 45% and
plasma 55% of the total blood volume.
– Blood volume: 4-5 L in females, 5-6 L in
males.
Blood Functions
• Distribution and transportation
– Respiration
– Nutritive
– Excretory
– Negative Aspects
• Regulation and Maintenance
– Hormonal regulation
– Thermoregulation
– pH / acid-base balance
– Fluid volume
• Protection
– Clotting
– Immunity
Major Components of the
Circulatory System
• Two divisions: Cardiovascular and lymphatic systems.
– Cardiovascular: Heart, blood vessels
• Heart
• Vessels
– Lymphatic: lymphatic vessels and lymphoid tissues in
spleen, thymus, tonsils, and lymph nodes.
• The fluid portion of the blood (plasma) passes through the
capillary walls under hydrostatic pressure (interstitial fluid).
• Some interstitial fluid returns to the blood and some enters the
lymphatic system
– Lymphatic vessels carry interstitial fluid now called lymph
back to the venous blood.
– Lymph nodes along the way filter and cleanse the blood
before it is returned.
Erythrocytes
• Structure
– Biconcave, anucleate
– 4.8 million/mm3 in
women.
– 5.4 million/mm3 in men.
– 7.5 um in diameter
• Components
– Hemoglobin
– Lipids, ATP, carbonic
anhydrase
• Function
– Transport oxygen from
lungs to tissues and carbon
dioxide from tissues to
lungs
Hemoglobin
• Consists of:
– 4 globin molecules: 2 alpha and 2 beta chains
• 280 million per RBC.
• Transport carbon dioxide (carbonic anhydrase involved), nitric
oxide.
– 4 heme molecules: Transport oxygen
• Iron is required for oxygen transport
Erythropoiesis
• Production of red blood cells
– Stem cells
proerythroblasts
early erythroblasts
intermediate
late
reticulocytes
• Erythropoietin: Hormone to stimulate RBC production
Hemolytic Anemia
Anemias
• Result of either a decrease in hemoglobin / RBC or in the
number of RBCs.
• Symptoms: pale, lethargic, shortness of breath, tired.
• Aplastic anemia: inability of red bone marrow to produce
RBCs
• caused by: damage to Red bone marrow, Iron of Folate
deficiency
• Pernicious anemia - Vitman B12 deficiency
• Hemorhagic anemia - results from loss of blood
• Hemolytic anemia - erythrocytes rupture or are destroyed
at an increased rate.
• Thalasemia - defective hemoglobin production
Malaria
Sickle cell anemia
Formed Elements
• Red blood cells (erythrocytes)
• White blood cells (leukocytes)
– Granulocytes
• Neutrophils
• Eosinophils
• Basophils
– Agranulocytes
• Lymphocytes
• Monocytes
• Platelets (thrombocytes)
Production of Formed Elements
• Hematopoiesis or hemopoiesis: Process of blood
cell production
• Stem cells: All formed elements derived from
single population
– Proerythroblasts: Develop into red blood cells
– Myeloblasts: Develop into basophils,
neutrophils, eosinophils
– Lymphoblasts: Develop into lymphocytes
– Monoblasts: Develop into monocytes
– Megakaryoblasts: Develop into platelets
Hematopoiesis
Neutrophil
• Appearance
– 2-5 lobes
– 10-12 um
– 54-62% of white cells
• Characteristics
– Fights bacterial and
fungal infections
– Contains peroxidases and
defensins
– Numbers increase with
meningitis and
appendicitis
Eosinophil
• Appearance
– Bilobed nucleus
– Red granules
– 11-14 um
– 1-3% of white blood cells
• Characteristics
– Fights parasitic infections.
– Releases antiinflammatory chemicals.
– Secretes enzymes that
break down clots.
Basophils
Basophil
Eosinophil
• Appearance
– Two indistinct lobes
– Blue-purple granules
– 10-12 um
– Less than 1% of WBC
• Characteristics
– Release histamine
– Chemoattractant for other
WBCs
– Releases heparin to
prevent clots.
Monocyte
• Apearance
– Nucleus round, kidney
or horseshoe shaped
– 12-20 um
– 3-9 % of WBC
• Characteristics
– Transforms into
macrophages
Lymphocyte
• Appearance
– Round nucleus
– 6-14 um
– 25-33% of WBC
• Characteristics
– Found in lymphoid tissue
– Provides specific immune
response
• T - lymphocytes
• B - lymphocytes
Leukocytes
Hemostasis
• Arrest of bleeding
• Events preventing excessive blood loss
– Vascular spasm: Vasoconstriction of damaged
blood vessels
– Platelet plug formation
– Coagulation or blood clotting
Thrombocytes
• Cell fragments pinched off
from megakaryocytes in
red bone marrow
• Important in preventing
blood loss
– Platelet plugs
– Promoting formation
and contraction of clots
Platelet Plug Formation
Coagulation
• Stages
– Activation of
prothrombinase
– Conversion of
prothrombin to
thrombin
– Conversion of
fibrinogen to fibrin
• Pathways
– Extrinsic
– Intrinsic
Clot Formation
Fibrinolysis
• Clot dissolved by
activity of plasmin, an
enzyme which
hydrolyzes fibrin
Blood Grouping
• Determined by antigens (agglutinogens) on
surface of RBCs
• Antibodies (agglutinins) can bind to RBC
antigens, resulting in agglutination (clumping) or
hemolysis (rupture) of RBCs
• Groups
– ABO and Rh
ABO Blood Groups
Agglutination Reaction
Rh Blood Group
• First studied in rhesus monkeys
• Types
– Rh positive: Have these antigens present on
surface of RBCs
– Rh negative: Do not have these antigens
present
• Hemolytic disease of the newborn (HDN)
– Mother produces anti-Rh antibodies that cross
placenta and cause agglutination and hemolysis
of fetal RBCs
Erythroblastosis Fetalis
Diagnostic Blood Tests
• Type and crossmatch
• Complete blood count
– Red blood count
– Hemoglobin measurement
– Hematocrit measurement
• White blood count
• Differential white blood count
• Clotting
Blood Disorders
• Erythrocytosis: RBC
overabundance
• Anemia: Deficiency of
hemoglobin
– Iron-deficiency
– Pernicious
– Hemorrhagic
– Hemolytic
– Sickle-cell
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Hemophilia
Thrombocytopenia
Leukemia
Septicemia
Malaria
Infectious mononucleosis
Hepatitis