The Cardiovascular System Blood

Functions of Blood I. TransportationI. Transportation –Oxygen –Carbon dioxide –Nutrients –Heat –Waste products –Hormones RBCs are most numerous, white blood cells are stained purple.

II. RegulationII. Regulation –pH using buffers –Body temperature –Water content of cells. Functions of Blood Water content of blood is regulated by the kidneys

III. ProtectionIII. Protection –Blood loss –Against microbes and viruses. Red Blood Cell Infected With Malaria Functions of Blood

Physical Characteristics of Blood TemperatureTemperature –38 C. More viscous than water.More viscous than water. pHpH – VolumeVolume –5-6 liters (male) –4-5 liters (female) Percent total body weightPercent total body weight –8 percent

Components of Blood I. PlasmaI. Plasma II. Formed elementsII. Formed elements –Red blood cells –White blood cells GranularGranular AgranularAgranular III. Platelets NeutrophilPlateletsRBC

Plasma Straw-colored liquid 91.5% water, 7% proteins Albumins maintain osmotic pressure Antibodies fight disease

Formation of Blood cells HemopoiesisHemopoiesis –Occurs in fetus Yolk sac, then liver, spleen and thymusYolk sac, then liver, spleen and thymus Red bone marrow- after birth and throughout lifeRed bone marrow- after birth and throughout life

Adult hemopoiesis Proximal ends of femur and humerus. Flat bones such as scapula, ribs, pelvis, sternum.Flat bones such as scapula, ribs, pelvis, sternum. Originates from hemopoietic stem cells that differentiate into five types of blood cells.

Erythrocytes: red blood cells Structure:Structure: –Biconcave discs. –8 microns in diameter –No nucleus or organelles. –Contains hemoglobin. –4.5 to 5.5 million per.mm 3. –4.5 to 5.5 million per. mm 3.

FunctionFunction –Carries oxygen & carbon dioxide. –Hemoglobin consists of four proteins attached to four hemes –Each heme has iron. –Iron attaches to oxygen.

–RBCs maintain a biconcave shape. –Maximum S.A. for gas exchange –2 million are made each second!

Recycling of a RBC –RBCs live from 3 to 120 days. –Removed by spleen, liver, and red bone marrow. (Macrophages)

Jaundice –The non- Iron part of hemoglobin is usually converted into bilirubin. –Liver then excretes it into the large intestine. –If the liver fails to process bilirubin in newborns, they will turn a yellow color: jaundice

Erythrocytes Production of RBCsProduction of RBCs –Erythropoiesis –Kidneys determine rate of RBC production. –Kidneys produce erythropoietin. Speeds up erythropoiesis.Speeds up erythropoiesis.

Leukocytes StructureStructure –Contains a nucleus. –Granular NeutrophilsNeutrophils EosinophilsEosinophils BasophilsBasophils –Agranular LymphocytesLymphocytes

Leukocytes FunctionsFunctions –Neutrophils and monocytes are phagocytic. –Monocytes are referred to as macrophages. –WBC’s are capable of emigration (diapedesis). –Capable of chemotaxis. Monocyte Tortora Pages

Leukocytes Life SpanLife Span –Most live just a few days. –Lymphocytes live years. –5, ,000/ mm 3. Tortora Pages

Leukocytes NumberNumber –5, ,000/ mm 3. Leukocytes are produced in the red bone marrow.Leukocytes are produced in the red bone marrow. Macrophages Tortora Pages

Thrombocytes StructureStructure –Fragment of cytoplasm surrounded by membrane. –Originate from a megakaryocyte. –Megakaryocyte fragments to form platelets. Thrombocyte Tortora Pages

Thrombocytes FunctionFunction –Forms a plug to stop bleeding. –Initiates clotting process.

Thrombocytes Life SpanLife Span –5 to 9 days. NumberNumber 250,000 to 400,000 mm 3.250,000 to 400,000 mm 3. ProductionProduction –Formed in red bone marrow.

Hemostasis Three mechanismsThree mechanisms –Vascular spasm –Platelet plug formation –Blood coagulation

Hemostasis Vascular SpasmVascular Spasm –Smooth muscle in wall contracts. –Initiated by nociceptors. –Lasts from 20 minutes to several hours.

Hemostasis Platelet Plug FormationPlatelet Plug Formation –Platelets get ‘sticky’ when they come in contact with a damaged blood vessel.

Hemostasis CoagulationCoagulation –Clotting involves several coagulation factors. Formation of prothrombinase.Formation of prothrombinase. Prothrombin converted to thrombin.Prothrombin converted to thrombin. Fibrinogen converted to fibrin by thrombin.Fibrinogen converted to fibrin by thrombin. Fibrin forms threads of protein that trap RBC’s to form clot.Fibrin forms threads of protein that trap RBC’s to form clot.

Hemostasis Extrinsic pathwayExtrinsic pathway –Initiated from outside the circulatory system –Tissue Factor (TF) found on surface of cells cause the formation of prothrombinase.

Hemostasis Intrinsic pathwayIntrinsic pathway –Initiated from inside the blood vessels. –Slower than extrinsic. –Initiated when blood contacts damaged endothelial cells.

Blood Groupings ABOABO –Based on types of proteins (antigens) on surface of the red blood cells. –Type A has only A antigen. –Type B has only B antigen. –Type O has none. –Type AB has both.

Blood Groupings Type O is the universal donor.Type O is the universal donor. Type AB is the universal recipientType AB is the universal recipient

Blood Groupings Typing Blood.Typing Blood. –Antisera –Clumping means antigen is present.

Blood Groupings RhRh –Separate system –Positive –Negative

Rh Incompatibility