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46 Cards in this Set
- Front
- Back
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Functions of blood |
transpot regulation protection |
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explain what blood transports |
-Oxygen and nutrients to the cells -Waste away from cells -Hormones |
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explain what blood regulates |
maintains body temp by absorbing and distributing heat |
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explain how blood protects |
prevents infection blood clotting prevents blood loss |
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composition of blood |
blood in composed of Plasma and formned elements |
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explain blood plasma |
90% water along with dissolved compounds Proteins– albumin, antibodies, clotting proteins Electrolytes– sodium, potassium, calcium, magnesium, chloride, bicarbonate |
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explain formed elements in blood |
erythrocytes, leukocytes,platelets |
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what do the proteins in the plasma do? |
maintain osmotic pressure |
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Albumin |
protein in plasma 60% of plasma proteins -transports substances such a bilirubin and bile salts |
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Globulins |
protein in plasma α , β –transports hormones, cholesterol, and iron; angiotensinogen and clotting factors Gamma globulins - antibodies |
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Fibrinogen |
protein in plasma precursor for the clotting protein fibrin |
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Erythrocytes (red blood cells) |
-Biconcaveshape -Containsno nucleus or organelles -Enzymesin cytoplasm: Glycolyticenzymes to carry out glycolysis Carbonicanhydrase – converts CO2 to HCO3 -Last~120 daysand are then destroyed by the spleen or liver |
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erythrocytes function/contains? |
- Function – to transport oxygen and to alesser extent carbon dioxide -Contains hemoglobin |
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hemoglobin |
in erythrocytes made of 4 globin polypeptides and 4 heme groups |
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Erythropoiesis |
production of new erythrocytes (~3 millionper second) -Occurs in the red bonemarrow -Rate of production is controlled by erythropoietin producedby the kidneys in response to blood oxygen levels |
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Anemia |
- decrease in oxygencarrying ability of the blood |
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Causes of anemia? |
-Decreasednumber of RBC (low hematocrit) -Deficientor abnormal hemoglobin -Deficiencyin iron or vitamin B12 -Kidneydisease, decrease in EPO -Bloodloss -Malaria,sickle-cell anemia |
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Polycythemia |
increased numbers oferythrocytes / hematocrit |
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Causes of Polycythemia |
cancer, high altitudes,lung and heart disease, dehydration |
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Leukocytes |
white blood cells |
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functions of Leukocytes |
-Protect againstinfection and initiates inflammation -Destroycancerous cells -Tissuerepair |
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type of Leukocytes |
granulocytes agranulocytes |
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granulocytes |
granule containing cells with lobed nuclei |
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types of granulocytes |
neutrophils eosinophils basophils |
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neutrophils (granulocyte) |
(60– 70%) -Phagocytes -Firston the scene of infection and triggers inflammation |
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eosinophils (granulocyte) |
(1-4%) associated with allergies and parasite infections |
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basophils (granulocyte) |
contain and release histamine (less than 1%) |
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type of agranulocytes |
monocytes lymphocytes |
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monocytes (agranulocytes) |
(2-6%) travel into tissue and mature into macophages |
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lymphocytes (agranulocytes) |
(25-33%) specific immune defense B cells and T cells |
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Hematopoiesis |
All blood cells arise from a common stem cell foundin the red bone marrow |
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Platelets (a.k.a thrombocytes) |
Irregularshaped cellfragments from megakaryocytes
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Platelets (a.k.a thrombocyte) play a role in: |
Playa role in bloodclotting |
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Platelets (a.k.a thrombocyte) and homeostasis |
–prevents the loss of blood when bloodvessels are damaged 3 phases: Vascularspasm Plateletplug formation Coagulation |
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Platelet plug formation |
-Brokenor damaged blood vessels cause platelets to become sticky and cling to the site -Releasechemicals that attract other platelets (ADP) -Releasechemicals that cause vasoconstriction: serotonin, epinephrine, thromboxane A2 |
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Vascular spasms |
Bloodvessels constrict to diminish blood flow and loss |
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Coagulation |
Formationof a network of fibers that seals the blood vessel -Involvesa clotting cascade |
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Clotting cascade |
-Involves12 clotting factors -Requiresthe presence of Ca2+ and platelet factor 3 (PF3) produced by aggregating platelets
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clotting cascade summary |
-Aninitial inactive clotting factor, found in the plasma, is activated by exposedcollagen -Thisactivates the next factor and so on….. Until thrombin converts fibrinogen intofibrin |
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Intrinsic Pathway of clotting cascade |
Initiatedwhen Hageman factor is activated by exposed collagen |
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Extrinsic Pathwayof clotting cascade |
Factor X is activated by thromboplastin released by damaged tissues |
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Role of Thrombin in clotting cascade |
-Convertsfibrinogen to fibrinq -Activatesstabilizing factor (XIII) -Enhancesconversion of more thrombin from prothrombin -Enhancesplatelet aggregation |
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Coagulation Clot retraction |
Platelets trapped in the clotcontract and squeeze serum out |
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Coaongulation Vessel repair |
Platelets attract fibroblaststhat repair blood vessel |
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Coaongulation Clot dissolution |
Thrombin and tissue plasminogenactivator (tPA) converts plasminogeninto plasmin which breaks down fibrin |
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Clotting disorders |
-Thromboembolism– clots forming in intact vessels -Imbalancein clotting – anticlotting mechanisms -Slowmoving blood -Releaseof thromboplastin from damaged tissue -Hemophilia– deficiency in one of the clotting factors (usually VIII), excessive bleeding -Thrombocytopenia– deficiency in platelets - Impairedliver -Lackof vitamin K |
