The circulatory system consists of what?
Heart, blood vessels, and blood.
The term cardiovascular system refers to what?
Heart, and vessels.
What are the functions of the circulatory system?
Transport, Protection, and Regulation
Plasma
Matrix of blood. A clear, light yellow fluid constituting a little over half of the blood volume.
Formed elements
Suspended in the plasma and consist of cells and cell fragments including the red blood cells, white blood cells, and platelets.
What are the seven kinds of formed elements?
1. Erythrocytes 2. Platelets 3. Neutrophils 4. Eosinophils 5. Basophils 6. Lymphocytes 7. Monocytes
Leukocytes are divided into what 2 categories?
Granulocytes and Agranulocytes
Which leukocytes are granulocytes?
Neutrophils, Eosinophils, and Basophils
Which leukocytes are agranulocytes?
Lymphocytes and Monocytes
Serum
Remaining fluid when blood clots and solids are removed. It is identical to plasma except for the absence of fibrinogen.
Protein is the most abundant ____ solute by weight.
Plasma
Albumin
the smallest and most abundant plasma protein. Contribute to viscosity and osmolarity: influence blood pressure, flow and fluid balance.
What are the three major categories of plasma proteins?
Albumins, Globulins, and Fibrinogen.
Globulins (antibodies)
Provide immune system functions. Produced by plasma cells
Fibrinogen
Precursor of fibrin threads that help form blood clots.
Where are plasma proteins formed?
The liver
The liver produces as much as __g of plasma protein per hour.
4
Viscosity
Resistance of fluid to flow, resulting from the cohesion of its particles
Osmolarity
The total molarity of those dissolved particles that cannot pas through the blood vessel wall.
If too high, blood absorbs too much water, increasing the blood pressure
If too low, too much water stays in tissue, blood pressure drops, and edema occurs
Opti
Hemopoiesis
Production of blood, especially its formed elements.
Hemopoietic Tissues
Produce blood cells. Their main function is to carry oxygen and Carbon Dioxide.
Erythrocytes or Red Blood Cells (RBCs) have two principal functions. What are they?
1. To pick up oxygen from the lungs and deliver it to tissues elsewhere and 2. to pick carbon dioxide from tissues and unload it in the lungs.
An erythrocyte is a ____ cell with a ____ shape.
1. Discoidal 2. Biconcave
Hemoglobin
33% of cytoplasm. The red pigment that gives an RBC its color and name. It is known especially for its role in oxygen transport, but it also aids in the transport of carbon dioxide and buffer the blood of pH.
Hemoglobin consist 4 protein chains called what?
Globins
Hematocrit (packed cell volume, PCV)
Percentage of whole blood volume composed of RBCS
Men 42% to 52% cells; Women 37% to 48%
Hemoglobin concentration of whole blood is normally ___ in men and ____ in women.
1.13-18 g/dl 2. 12-16 g/dl
Erythropoiesis
RBC production
Erythropoietin (EPO)
A A hormone secreted by the kidneys. EPO stimulates the ECFU to transform into an erythroblast which multiply and synthesize hemoglobin
Iron is a critical part of the hemoglobin and therefore one of the key nutritional requirements for what?
Erythropoiesis.
The RBC count is maintained by a classic ___ ____ manner.
negative feedback
Hypoxemia
A drop in RBC count detected by the kidneys
Where is the "erythrocyte graveyard" located?
The spleen.
Hemolysis
The Rupture of RBCs, releases hemoglobin and leaves empty plasma membranes.
Primary Polycythemia (Polycythemia Vera)
Is due to cancer of the erythropoietic line of the red bone marrow. RBC count as high as 11 million RBCs/uL; hematocrit 80%
The cause of anemia fall into what 3 categories?
1. Inadequate erythropoiesis or hemoglobin synthesis
2. Hemorrhagic anemia from bleeding
3. Hemolytic anemia from RBC destruction
What is the most common form of anemia?
Iron- deficiency anemia
Intrinsic factor
a substance secreted by the stomach that enables the body to absorb vitamin B12. It is a glycoprotein.
Pernicious Anemia
an autoimmune disease in which antibodies destroy stomach tissue. Leads to inadequate vitamin B12 absorption
Effects the elderly
can be hereditary
Treatable with vitamin B12 injections or oral B12 and intrinsic factor
aplastic anemia
Complete cessation of erythropoiesis
Leads to grotesque tissue necrosis and blackening of the skin.
Most victims die within a year
About half of cases are of unknown or hereditary cause.
Sickle-cell disease
Hereditary defects that occur mostly among people of african descent.
Caused by recessive allele that modifies structure of Hb (makes HbS)
HbS does not bind to oxygen well and RBCs become rigid, sticky, pointed at ends. They clump together and block small
Antigens
Complex molecules on surface of cell membrane that activate an immune response
Used to distinguish self from foreign matter.
Foreign antigens generate an immune response
Agglutinogens
Antigens on the surface of the RBC that are the basis for blood typing.
Antibodies
Proteins (gamma globulins) secreted by plasma cells.
Part of immune response to foreign matter
Bind to antigens and mark them for destruction
Agglutination
Antibody molecule binding to antigens. Causes clumping of red blood cells
What is the most common blood type?
O
What blood type is the universal donor?
O
What blood type is the universal recipient?
AB
What blood type is the rarest?
AB
RH Blood group
Contains numerous RBC antigens, of which the principal types are antigens C, D, and E
Antigen D is not normally present. They form in Rh- individuals exposed to Rh+ blood.
~ Rh- woman with fetus or transfusion of Rh+ blood
~No problems with first transfus
Hemolytic disease of the newborn (HDN) or erythroblastosis fetalis
Baby is born with a severe anemia.
Occurs if Rh- mother has formed antibodies and is pregnant with second Rh+ child.
Prevention:
RhoGAM given to pregnant Rh- women
~Binds fetal agglutinogens in her blood so she will not
form anti-D antibodies.
Leukocytes or White blood cells (WBCs)
Are the least abundant formed elements, totaling only 5,00 to 10,000.
Protect against infectious microorganisms and other pathogens
Neutrophils
60% to 70% of circulating leukocytes.
Barely visible granules in cytoplasm; three to five lobed nucleus
Aggressively antibacterial.
Eosinophils
2% to 4% of WBC total.
Large rosy-orange granules; bilobed nucleus
Count fluctuates greatly. It rises in allergies, parasitic infections, collagen disease of the spleen and central nervous system.
Basophils
Less than 1% of the WBCs.
Large, abundant, violet granules (obscure a large S-shaped nucleus)
Secrets 2 hormones- Histamine and Heparin
Basophils secret two chemicals that aid in the body's defense processes. What are they and what do they do?
1. Histamine- Vasodilator that speeds flow of blood to an injured area
2. Heparin- anticoagulant that promotes the mobility of other WBCs in the area
Lymphocytes
25% to 33% of the WBC count.
Increased numbers in diverse infections and immune responses.
Destroy cells (cancer, foreign, and virally infected cells)
Monocytes
3% to 8% of the WBC count.
Increased numbers in viral infections and inflammation.
They leave the bloodstream and transform into macrophages. They phagocytize pathogens and debris
Leukopoiesis
Production of white blood cells.
Leukopenia
A count below the normal 5,000 to 10,000 WBC
Caused by radiation, poisons, infectious disease
Elevates risk of infection
Leukocytosis
A count above 10,000 WBC
Caused by infection, allergy, disease
Differential WBC count: identifies what percentage of the total WBC count consist of each type of leukocyte
Leukemia
Cancer of the hemopoietic tissue usually producing a very high number of circulating leukocytes
Myeloid Leukemia
Uncontrolled granulocyte production
Lymphoid Leukemia
Uncontrolled lymphocyte or monocyte production
Hemostasis
The cessation of bleeding.
Stopping potentially fatal leaks
Platelets are not cells but what?
Small fragments of marrow cells called megakaryocyte cells
The production of platelets is a division of hemopoiesis called what?
Thrombopoiesis
Thrombocytopenia
A dangerous platelet deficiency.
Happens when anything interferes with platelet production.
Vascular Spasm
Prompt constriction of a broken vessel
Most immediate protection against blood loss
Platelet Plug
platelets stick together to form a temporary seal to cover the break in the vessel wall.
Platelets degranulate releasing a variety of substances: Serotonin (vasoconstrictor).
The plug is looser and more delicate than the blood clot to follow which is why
Coagulation
Clotting which is the last and most effective defense against bleeding.
Conversion of plasma protein fibrinogen into insoluble fibrin threads to form framework of clot
Extrinsic pathway- Factors released by damaged tissues begin cascade
Intrinsic pathway-
What are the three hemostatic mechanisms?
1. Vascular spasm
2. Platelet plug formation
3. Coagulation
Degranulation
is a cellular process that releases antimicrobial cytotoxic molecules from secretory vesicles called granules found inside some cells. It is used by several different cells involved in the immune system, including granulocytes (neutrophils, basophils and
Extrinsic Pathway
Initiated by release of tissue thromboplastin from damaged tissue
Intrinsic Pathway
Initiated by platelets releasing Hageman factor
Fibrinolysis
The dissolution of a clot.
Hemophilia
A deficiency of any clotting factor can shut down the coagulation cascade.
Family of hereditary diseases characterized by deficiencies of one factor or another
Sex-linked trait
Hematomas
Masses of clotted blood in the tissues
Thrombosis
Abnormal clotting in unbroken blood vessel.
Thrombus (clot)
Most likely to occur in leg veins of inactive people.
Embolus
Anything that can travel in the blood and blood blood vessels
Erythrocytes and albumin are mainly responsible for the ___ of blood, its resistance to flow.
Viscosity