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BIO 151 A&P II > Unit 1: Ch 18, 19, 20 > Flashcards

Unit 1: Ch 18, 19, 20 Flashcards

1
Q

ABO Blood Group Determination

A
  • Hereditary presence or absence of antigens A and B on the RBCs
    • Type O: doesn’t agglutinate in either one
    • Type A or B: agglutinates only in the corresponding antiserum
    • Blood type AB: exhibits agglutination in both antisera
  • Wright stain test
    • Determined by placing a drop of blood in a pool of anti-A serum and another drop in a pool of anti-B
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2
Q

Agglutination

  • Description
A
  • Antibody molecules that bind to antigens; “clumping of RBCs”
    • Can attach to foreign antigens on different RBCs at the same time
    • Agglutinated RBCs block small blood vessels, hemolyze, and release their hemoglobin over the next few hours or days
  • Responsible for mismatched transfusion reaction
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3
Q

Anemia

  • What causes it?
  • How does it effect the body?
A
  • Causes
    • Kidney failure
    • Dietary deficiency
  • Effects
    • Reduced blood osmolarity
    • Reduced blood viscosity
    • Hypoxia
      • Lethargy
      • Shortness of breath
      • Necrosis of brain, heart, or kidney
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4
Q

Anemia Types

  • List & describe
A
  • Aplastic anemia: complete cessation of erythropoiesis
  • Hypoplastic anemia: decline in erythropoiesis
  • Iron-deficiency anemia: nutritional anemia
  • Pernicious anemia: autoimmune disease in which antibodies destroy stomach tissue
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5
Q

Antibodies

  • Description
  • Types
A
  • An immune system protein that aids in immune response
  • Types
    • Anti-A and -B
      • Appear 2 to 8 months after birth
      • Maximum concentration by 10 YOA
      • Do not form antibodies against your antigens
    • Anti-D
      • Form only in Rh- individuals who are exposed to Rh+ blood (transfusion or birth)
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6
Q

Antigens

  • Description
A
  • Any substance that is capable of causing an immune reaction
  • Usually proteins, glycoproteins, or glycolipids
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7
Q

Basophils

  • Cell type
  • Secretions and their functions
A
  • A type of granulocyte
  • Fight fungal or bacterial infections and viruses
    • Secrete heparin (anticoagulant): promotes the mobility of other WBCs in the area
    • Secrete histamine (vasodilator): speeds flow of blood to an injured area
  • Increased numbers found in chickenpox, sinusitis, diabetes
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8
Q

Blood Clot Dissolution

  • List & describe the 3 approaches
A
  • Hementin: produced by giant Amazon leech
  • Streptokinase: enzyme made by streptococci bacteria
    • Used to dissolve clots in coronary vessels
    • Digests almost any protein
  • Tissue plasminogen activator (TPA): works faster, is more specific, and now made by transgenic bacteria
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9
Q

Blood Clot Prevention

  • List & describe the 3 approaches
A
  • Aspirin
    • Suppresses thromboxane A2
  • Vitamin K
    • Required for formation of clotting factors
    • Examples: Coumarin, warfarin (Coumadin)
  • Other anticoagulants discovered in animal research
    • Medicinal leeches used since 1884 (hirudin)
    • Snake venom from vipers (arvin)
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10
Q

Blood Clot Retraction

  • Methods and descriptions
  • Timing of clot retraction
A
  • Methods
    • Platelet-derived growth factor secreted by platelets and endothelial cells
      • Mitotic stimulant for fibroblasts and smooth muscle to multiply and repair damaged vessel
    • Fibrinolysis—dissolution of a clot
      • Factor XII speeds up formation of kallikrein enzyme
      • Kallikrein converts plasminogen into plasmin, a fibrin-dissolving enzyme that breaks up the clot
  • Retraction occurs within 30 minutes
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11
Q

Blood Components

A
  1. Liquid connective tissue: adults have 4-6 L of blood
  2. Extracellular matrix: blood plasma
  3. Formed elements: RBC, WBC, and platelets
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12
Q

Blood Plasma

  • Description
A
  • The liquid portion of blood (serum) after blood clots and solids are removed
  • Identical to plasma except for the absence of fibrinogen
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13
Q

Blood Production

(Daily for adults)

A
  • 400 billion platelets
  • 200 billion RBCs
  • 10 billion WBCs
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14
Q

Blood Type Discovery

  • Who discovered ABO blood types
  • What is its significance
A
  • Karl Landsteiner discovered blood types A, B, and O in 1900
    • Won a Nobel Prize in 1930
    • Type AB discovered later
  • Blood types and transfusion compatibility are a matter of interactions between plasma proteins and erythrocytes
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15
Q

Blood Viscosity

  • Description
  • Ratio to water
  • Ratio to plasma
A
  • Resistance of fluid to flow, resulting from the cohesion of its particles
    • Whole blood 4.5 - 5.5 times as viscous as water
    • Plasma is 2x as viscous as water; important in circulatory function
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16
Q

Cardiovascular System Components

A
  • Heart
  • Blood Vessels
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17
Q

Centrifugation

  • Description
A
  • Separates the formed elements
  • Determines hematocrit (packed cell volume)
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18
Q

Charles Drew

A
  • Blood banking pioneer
    • First black person to pursue advanced degree in medicine to study transfusion and blood banking
    • Used plasma rather than whole blood; caused less transfusion reactions
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19
Q

Circulatory System Components

A
  • Heart
  • Blood vessels
  • Blood
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20
Q

Circulatory System Functions

A
  • Transport
    • O2, CO2, nutrients, wastes, hormones, and stem cells
  • Protection
    • Inflammation, limit spread of infection, destroy microorganisms and cancer cells, neutralize toxins, and initiate clotting
  • Regulation
    • Fluid balance, stabilizes pH of ECF, and temperature control
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21
Q

Coagulation Pathways

A
  • Extrinsic pathway
    • Factors released by damaged tissues begin the cascade
    • Initiated by release of tissue thromboplastin (factor III) from damaged tissue
    • Cascades to factor VII, V, and X
  • Intrinsic pathway
    • Factors found in blood begin the cascade (platelet degranulation)
    • Initiated by platelets releasing Hageman factor (factor XII)
    • Cascades to factor XI to IX to VIII to X
  • Calcium required for both pathways
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22
Q

Coagulation Process

A
  1. Activation of factor X
  2. Production of prothrombin activator
  3. Prothrombin converted to thrombin
  4. Thrombin converts fibrinogen into fibrin

Positive feedback loop: thrombin speeds up formation of prothrombin activator

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23
Q

Disseminated Intravascular Coagulation (DIC)

A
  • Widespread clotting within unbroken vessels
    • Limited to one organ or occurring throughout the body
    • Usually triggered by septicemia but also occurs when blood circulation slows markedly (as in cardiac arrest)
    • Marked by wide-spread hemorrhaging, congestion of the vessels with clotted blood, and tissue necrosis in blood-deprived organs
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24
Q

Embolus

A
  • Anything that can travel in the blood and block blood vessels
    • Infarction (tissue death) may occur if clot blocks blood supply to an organ (MI or stroke)
    • 650,000 Americans die annually of thromboembolism (traveling blood clots)
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25
Q

Eosinophils

A
  • Type of granulocyte
  • Increased numbers in parasitic infections, collagen diseases, allergies, diseases of spleen and CNS
    • Phagocytosis of antigen–antibody complexes, allergens, and inflammatory chemicals
    • Release enzymes to destroy large parasites
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26
Q

Erythrocyte death & disposal process

A
  • RBCs & macrophages in spleen
  • Separate heme from globin
    • Globins hydrolyzed into amino acids
    • Iron removed from heme
      • Heme pigment converted to biliverdin (green)
      • Biliverdin converted to bilirubin (yellow)
      • Released into blood plasma (kidneys—yellow urine)
  • Liver removes bilirubin and secretes into bile
    • Concentrated in gallbladder: released into small intestine; bacteria create urobilinogen (brown feces)
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27
Q

Erythrocyte Disorders

  • Description
  • List and describe the 2 types
A
  • Imbalance between the rates of erythropoiesis and RBC destruction
  • Types
    • Polycythemia: RBC excess
    • Anemia: RBC or hemoglobin deficiency
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28
Q

Erythrocyte / RBC Functions

A
  • Carry oxygen from the lungs and deliver it to tissues
  • Pick up CO2 from tissues and bring to lungs
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29
Q

Erythrocytes / RBCs

  • Shape
  • Description
A
  • Disc-shaped cell with thick rim
  • Most abundant formed elements of the blood and most critical to survival
    • It is the lack of life-giving oxygen, carried by erythrocytes, that leads rapidly to death in cases of major trauma
    • The only human cells that carry on anaerobic fermentation indefinitely
  • Lose nearly all organelles during development
    • Lack mitochondria; rely exclusively on anaerobic fermentation to produce ATP
    • Lack of nucleus and DNA; no protein synthesis or mitosis
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30
Q

Fibrinogen

A
  • Becomes fibrin, the major component of blood clots
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31
Q

Formed Elements

  • List various types
A
  • Erythrocytes (RBC)
  • Platelets
  • Leukocytes (WBC)
    • Granulocytes (with granules)
      • Basophils
      • Eosinophils
      • Neutrophils
    • Agranulocytes (without granules)
      • Lymphocytes
      • Monocytes
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32
Q

Fractionation

A
  • Fractionation of blood into formed elements, plasma, and serum
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33
Q

Hematocrit

A
  • The percentage by volume of red cells in your blood
  • Packed cell volume
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34
Q

Hematology

A
  • The study of blood
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35
Q

Hematomas

  • Description
A
  • Masses of clotted blood in the tissues
    • Thrombosis: Abnormal clotting in unbroken vessel
    • Thrombus: Clot most likely to occur in leg veins of inactive people
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36
Q

Hematopoiesis

A
  • The production of blood, especially its formed elements
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37
Q

Hematopoietic stem cells (HSC)

  • What do they produce?
A
  • Differentiate into distinct types of colony-forming units (CFU) and then produce the following cell lines, each committed to a certain outcome
    • Myeloblasts: differentiate into 3 types of granulocytes
      • basophils
      • eosinophils
      • neutrophils
    • Monoblasts: lead ultimately to monocytes
    • Lymphoblasts: produce all lymphocyte types
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38
Q

Hemoglobin Degradation

  • 5 streams
A
  1. Heme → Biliverdin → Bilirubin → Bile → Feces
  2. Heme → Iron → Storage → Reuse
  3. Heme → Iron → Reuse
  4. Heme → Iron → Loss by menstruation, injury, etc
  5. Globin → Hydrolyzed to free amino acids
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39
Q

Hemolysis

A
  • Rupture of RBCs
    • Releases hemoglobin and leaves empty plasma membranes
    • Membrane fragments digested by macrophages in the liver and spleen
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40
Q

Hemolytic disease of the newborn (HDN) / erythroblastosis fetalis

  • Description
  • Causes
A
  • Can occur when a woman has a baby with a mismatched blood type, typically when she is Rh- and carries an Rh+ fetus
  • Causes
    • Mismatched Rh type (most severe)
    • Mismatched ABO type
    • Mismatched Kell blood group
    • Mismatched Kidd
    • Mismatched Duffy
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41
Q

Hemophilia

  • Description
  • Types
A
  • A family of hereditary diseases characterized by deficiencies of one factor or another
    • Occurs predominantly in males
    • Can inherit it only from mothers
  • Types
    • Classical hemophilia (hemophilia A): Lack of factor VIII
    • Hemophilia B: Lack of factor IX
    • Hemophilia C: Lack of factor XI; autosomal and not sex-linked - occurs equally in both sexes
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42
Q

Hemostasis

A

The cessation of bleeding

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43
Q

Hemostatic Mechanisms

A
  • Vascular spasm
    • Immediate protection against blood loss
    • Constriction of broken blood vessels
  • Platelet plug formation
    • Mass of formed platelets
  • Blood clotting (coagulation)
    • The last but most effective defense against bleeding
    • Converts fibrinogen into fibrin
    • 2 reaction pathways
      • Extrinsic mechanism: initiated by clotting factors released by the damaged blood vessel and perivascular tissues. Come from sources external to the blood itself
      • Intrinsic mechanism: Uses only clotting factors found in the blood itself
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44
Q

Hypoproteinemia

A
  • “Starvation” / deficiency of plasma proteins
    • extreme starvation
    • liver or kidney disease
    • severe burns
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45
Q

Hypoxemia

  • Description
  • Causes
A
  • Oxygen deficiency in the blood
  • Causes
    • Blood loss
    • Low levels of oxygen in the atmosphere
    • Abrupt increase in the body’s oxygen consumption
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46
Q

Infectious mononucleosis

A
  • Infection of B lymphocytes with Epstein-Barr virus
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47
Q

Kernicterus

  • Description & cause
  • Treatments
A
  • Syndrome of toxic brain damage that can be lethal or leave the child with motor, sensory, and mental deficiencies
  • Caused by HDN; high bilirubin levels
  • Treatments
    • Phototherapy: exposes the infant to ultraviolet radiation
    • Exchange transfusion: completely replaces an infant’s Rh+ blood with Rh-
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48
Q

Kwashiorkor

A
  • Children with severe plasma protein deficiency
    • Thin arms and legs
    • Swollen abdomen
  • Fed on cereals once weaned
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49
Q

Leukemia classifications

  • List and describe the 4 types of leukemia
A
  • Acute leukemia
    • Appears suddenly, progresses rapidly, and causes death if untreated
  • Chronic leukemia
    • Develops more slowly and may go undetected
    • If untreated, the typical survival time is 3 yrs
  • Lymphoid leukemia
    • Uncontrolled lymphocyte or monocyte production
  • Myeloid leukemia
    • Uncontrolled granulocyte production
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50
Q

Leukocyte disorders

  • List and describe the 3 primary leukocyte disorders
A
  1. Leukocytosis—high WBC count: above 10,000 WBCs/mL
    • Causes: infection, allergy, disease
    • Differential WBC count: identifies what percentage of the total WBC count consist of each type of leukocyte
  2. Leukemia—cancer of hemopoietic tissue that usually produces an extraordinary high number of circulating leukocytes and their precursors
    • Effects: normal cell percentages disrupted; impaired clotting; opportunistic infections
  3. Leukopenia—low WBC count: below 5,000 WBCs/mL
    • Causes: radiation, poisons, infectious disease
    • Effects: elevated risk of infection
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51
Q

Leukocytes / WBCs

  • Description
A
  • Least abundant formed elements
  • Protect against infection & other diseases
  • Differ from RBCs in that they retain their organelles throughout their life
  • Conspicuous nucleus
  • Retain their organelles for protein synthesis
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52
Q

Lymphocytes

  • Cell type
  • Function
  • Effect
A
  • Type of agranulocyte
  • Function
    • Destroy cells (cancer, foreign, and virally infected cells)
    • “Present” antigens to activate other immune cells
    • Secrete antibodies and provide immune memory
  • Increased numbers in diverse infections and immune responses
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53
Q

Monocytes

A
  • Type of agranulocyte
  • Increased numbers in viral infections and inflammation
    • Leave bloodstream and transform into macrophages
    • Phagocytize pathogens and debris
    • “Present” antigens to activate other immune cells—antigen-presenting cells (APCs)
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54
Q

Myeloid

A
  • Blood formation in the bone marrow
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55
Q

Neutrophils

A
  • Type of granulocyte
  • Increased numbers in bacterial infections
    • Phagocytosis of bacteria
    • Release antimicrobial chemicals
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56
Q

Opportunistic infection

A
  • The establishment of pathogenic organisms that usually cannot get a foothold in people with healthy immune systems
  • Caused by the deficiency of competent WBCs
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57
Q

Osmolarity of blood

  • Description
  • Effect if too high & low
A
  • The total molarity of dissolved particles that cannot pass 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
  • Optimum osmolarity is achieved by the body’s regulation of sodium ions, proteins, and RBCs
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58
Q

Other blood groups

  • Description
  • Types
A
  • Rarely cause transfusion reactions
  • Useful for legal purposes (paternity) and criminal cases
  • Now that DNA sequencing is more economical, it has replaced blood typing in many applications
  • Types
    • Duffy
    • Kell
    • Kidd
    • Lewis
    • MNS
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59
Q

Plasma Proteins Role

A
  • Clotting
  • Defense against pathogens
  • Transport of other solutes such as iron, copper, lipids, and hydrophobic hormones
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60
Q

Plasma Proteins

  • Description
  • Categories
A
  • Formed by liver, except globulins which are produced by plasma cells
  • Categories
    1. Albumins
      • smallest and most abundant
      • contribute to visosity and osmolarity
      • influence blood pressure, flow and fluid balance
    2. Globulins
      • antibodies
      • provide immune system functions
      • alpha, beta, and gamma globulins
    3. Fibinogen
      • precursor of fibrin threads that help form blood clots
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61
Q

Platelet Functions

A
  • Initiate the formation of a clot-dissolving enzyme
  • Secrete vasoconstrictors
  • Internalize and destroy bacteria
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62
Q

Platelet Production

  • List & describe the 3 platelet cell types
A
  • Thrombopoiesis
    • Stem cells (that develop receptors for thrombopoietin) become megakaryoblasts
  • Megakaryoblasts
    • Repeatedly replicate DNA without dividing
  • Megakaryocytes
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63
Q

Pulmonary Embolism

A
  • When a blood clot breaks free and travels from veins to lungs
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64
Q

Reasons oxygen in blood are higher in women

A
  • Androgens stimulate RBC production, and men have higher androgen levels than women
  • Women of reproductive age have periodic menstrual losses
  • The hematocrit is inversely proportional to % of body fat, which average higher in women
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65
Q

Red bone marrow

A
  • Produces all 7 formed elements
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66
Q

Rh blood group

  • Description
  • Antigens
  • Prevention
  • Rh determination
A
  • Description
    • Named for the rhesus monkey
    • ABO blood type has no influence on Rh type
    • Occurs if Rh- mother has formed antibodies and is pregnant with second Rh+ child
      • Anti-D antibodies can cross placenta
  • Prevention
    • RhoGAM given to pregnant Rh- women
      • Binds fetal agglutinogens in her blood so she will not form anti-D antibodies
  • Antigens
    • Principal RBC antigen types are C, D, and E
    • Antigen D is the most reactive
  • Determination
    • Rh+ if a person has antigen D
    • Rh- if someone does not have antigen D
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67
Q

Sickle-Cell Disease

A
  • Hereditary hemoglobin defects that occur mostly among people of African descent
  • Caused by a recessive allele that modifies the structure of the hemoglobin molecule (HbS)
    • Differs only on the sixth amino acid of the beta chain
    • HbS does not bind oxygen well
    • RBCs become rigid, sticky, pointed at ends
    • Clump together and block small blood vessels causing intense pain
    • Can lead to kidney or heart failure, stroke, rheumatism, or paralysis
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68
Q

Thalassemia

A
  • Hereditary anemias most common in Greeks, Italians, and others of Mediterranean descent
  • Deficiency or absence of alpha or beta hemoglobin and RBC counts that may be less than 2 million
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69
Q

Thrombocytopenia

A
  • Platelet counts below 100k
  • Causes include bone marrow destruction by radiation, drugs, poisons, or leukemia
  • Signs include small hemorrhagic spots in the skin or hematomas in response to minor trauma
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70
Q

Blood Type Compatibility

A
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71
Q

Universal Donor & Recipient

  • Description of each
A
  • Universal donor
    • Type O: most common blood type
    • Lacks RBC antigens
    • Donor’s plasma may have both antibodies against recipient’s RBCs (anti-A and anti-B)
    • May give packed cells (minimal plasma)
  • Universal recipient
    • Type AB: rarest blood type
    • Lacks plasma antibodies; no anti-A or anti-B
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72
Q

Cardiovascular System Components

A
  • Heart
  • Blood vessels
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73
Q

Circulatory System Components

A
  • Heart
  • Blood vessels
  • Blood
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74
Q

Circulatory System Divisions

  • List and describe
A
  • Pulmonary circuit
    • Right side of heart
    • Carries blood to lungs for gas exchange and back to heart
    • Lesser oxygenated blood arrives from inferior and superior venae cavae
    • Blood sent to lungs via pulmonary trunk
  • Systemic circuit
    • Left side of heart
    • Supplies oxygenated blood to all tissues of the body and returns it to the heart
    • Fully oxygenated blood arrives from lungs via pulmonary veins
    • Blood sent to all organs of the body via aorta
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75
Q

Heart Base & Apex

  • Describe
A
  • Base
    • Wide, superior portion of heart
    • Blood vessels attach here
  • Apex
    • Inferior end
    • Tilts to the left, tapers to point
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76
Q

Pericardium

  • Describe
A
  • Double-walled sac (pericardial sac) that encloses the heart
    • Allows heart to beat without friction, provides room to expand, yet resists excessive expansion
    • Anchored to diaphragm inferiorly and sternum anteriorly
77
Q

Parietal Pericardium

A
  • Outer wall of sac
    • Superficial fibrous layer of connective tissue
    • Deep, thin serous layer
78
Q

Epicardium (Visceral Pericardium)

A
  • Heart covering
    • Serous lining of sac turns inward at base of heart to cover the heart surface
    • Adipose in thick layer in some places
    • Coronary blood vessels travel through this layer
79
Q

Pericardial Cavity

A
  • Space inside the pericardial sac filled with 5 to 30 mL of pericardial fluid
80
Q

Pericarditis

A
  • Inflammation of the membranes
    • Painful friction rub with each heartbeat
81
Q

Endocardium

A
  • Smooth inner lining of heart and blood vessels
  • Covers the valve surfaces and is continuous with endothelium of blood vessels
82
Q

Myocardium

A
  • Layer of cardiac muscle proportional to work load
    • Muscle spirals around heart which produces wringing motion
83
Q

Heart Chambers

A
  • Right and left atria
    • Two superior chambers
    • Receive blood returning to heart
    • Auricles (seen on surface) enlarge chamber
  • Right and left ventricles
    • Two inferior chambers
    • Pump blood into arteries
84
Q

Atrioventricular Sulcus

A
  • Separates atria and ventricles
85
Q

Interventricular Sulcus

A
  • Overlies the interventricular septum that divides the right ventricle from the left
86
Q

Right Atrium

A
  • Receives oxygen poor blood from body
  • Filling chamber
87
Q

Right Ventricle

A
  • Pumps blood to lungs to get oxygen and get rid of CO2
88
Q

Left Atrium

A
  • Receives oxygen rich blood from lungs
  • Filling station
89
Q

Left Ventricle

A
  • Pumps oxygen rich blood to the entire body
90
Q
A
92
Q

Atrioventricular (AV) Valves

  • Description
A
  • Control blood flow between atria and ventricles
    • Right AV valve has three cusps (tricuspid valve)
    • Left AV valve has two cusps (mitral or bicuspid valve)
93
Q

Semilunar Valves

  • Function
  • List & describe the two valves
A
  • Control flow into great arteries; open and close because of blood flow and pressure
    • Pulmonary semilunar valve: an opening between right ventricle and pulmonary trunk
    • Aortic semilunar valve: an opening between left ventricle and aorta
94
Q

Blood flow through the chambers

  • 11 steps
A
  1. Blood enters right atrium from superior and inferior venae cavae
  2. Blood in right atrium flows through right AV valve into right ventricle
  3. Contraction of right ventricle forces pulmonary valve open
  4. Blood flows through pulmonary valve into pulmonary trunk
  5. Blood is distributed by right and left pulmonary arteries to the lungs, where it unloads CO2 and loads O2
  6. Blood returns from lungs via pulmonary veins to left atrium
  7. Blood in left atrium flows through left AV valve into left ventricle
  8. Contraction of left ventricle (simultaneous with step 3) forces aortic valve open
  9. Blood flows through aortic valve into ascending aorta
  10. Blood in aorta is distributed to every organ in the body, where it unloads O2 and loads CO2
  11. Blood returns to the heart via venae cavae
95
Q

Where does the left & right coronary artery branch off from?

A
  • Ascending aorta
96
Q

Cardiocytes

  • Describe
A
  • Structure of the cardiac muscle
    • Striated, short, thick, branched cells
    • One central nucleus surrounded by light-staining mass of glycogen
97
Q

Conduction System

  • Description
  • List the nodes (in order of ventricular filling)
A
  • Coordinates the heartbeat
    • Composed of an internal pacemaker and nervelike conduction pathways through myocardium
  • Nodes (in order of ventricular filling)
    1. Sinoatrial (SA) node
    2. Atrioventricular (AV) node
    3. Atrioventricular (AV) bundle
    4. Purkinje fibers
98
Q

What steps are involved in the conduction system?

A
  1. SA node fires
  2. Excitation spreads through atrial myocardium
  3. AV node fires
  4. Excitation spreads down AV bundle
  5. Purkinje fibers distribute excitation through ventricular myocardium
99
Q

Nerves that supply to the heart

  • List & describe
A
  1. Sympathetic nerves: raises heart rate
  2. Parasympathetic nerves: slows heart rate
100
Q

Electrical & contractile activity of the heart

  • Systole
  • Diastole
  • Blood pressure measurement formula
A
  • Systole: atrial or ventricular contraction
  • Diastole: atrial or ventricular relaxation
  • Systole / diastole = blood pressure
101
Q

Cardiac Rhythm

  • List
A
  • Sinus rhythm
  • Ectopic rhythm
  • Ectopic foci
  • Arrhythmia
102
Q

Cardiac Cycle

  • Description
  • Cycle components and when they occur
A
  • One complete contraction and relaxation of all four chambers of the heart
  • Cycle components
    • Diastole (relaxation)
      • ​Occurs while ventricles in systole
    • ​Systole (contraction)
      • ​Occurs while ventricles are in diastole
    • Quiescent period
      • ​When all four chambers relaxed at same time
103
Q

Main variables that govern fluid movement

A
  1. Pressure causes a fluid to flow (fluid dynamics)
    • Pressure gradient—pressure difference between two points
    • Measured in mm Hg with a manometer or sphygmomanometer
  2. Resistance opposes fluid flow
104
Q

Valvular insufficiency disorders

  • Description
  • List types
A
  • Any failure of a valve to prevent reflux, the backward flow of blood
    1. Valvular stenosis
    2. Mitral valve prolapse
105
Q

Heart Sounds

A
  • S1
    • First heart sound
    • Louder and longer “lubb”
    • Occurs with closure of AV valves, turbulence in the bloodstream, and movements of the heart wall
  • S2
    • Second heart sound
    • Softer and sharper “dupp”
    • Occurs with closure of semilunar valves, turbulence in the bloodstream, and movements of the heart wall
  • S3
    • Rarely heard in people over 30
106
Q

Ventricular Filling Phases

A
  1. Rapid ventricular filling
    • First one-third
    • Blood enters very quickly
  2. Diastasis
    • Second one-third
    • Marked by slower filling
    • P wave occurs at the end of diastasis
  3. Systole
    • Final one-third
    • Atria contract
107
Q

Edema

  • Types & description
  • Which side will have fluid accumulation?
A
  • Pulmonary edema
    • When the left ventricle pumps less blood than the right, and blood pressure backs up into the lungs
  • Systemic edema
    • When the right ventricle pumps less blood than the left, and pressure backs up in the systemic circulation
  • The side that is working too hard is the side that will have fluid accumulation
108
Q

Congestive Heart Failure (CHF)

A
  • Results from the failure of either ventricle to eject blood effectively
109
Q

Left ventricular failure

A
  • Occurs when blood backs up into the lungs causing pulmonary edema
    • Shortness of breath or sense of suffocation
    • Eventually leads to total heart failure
110
Q

What does cardiac output measure?

A

The amount of blood ejected by the ventricles in 1 minute

111
Q

Pulse

A
  • Surge of pressure produced by each heart beat
  • Can be felt by palpating a superficial artery with the fingertips
    • Never use thumb to take pulse because it has it’s own heart rate
112
Q

Trachycardia

A
  • Resting adult heart rate above 100 bpm
    • Stress, anxiety, drugs, heart disease, or fever
    • Loss of blood or damage to myocardium
113
Q

Bradycardia

A
  • Resting adult heart rate of less than 60 bpm
    • In sleep, low body temperature, and endurance-trained athletes
114
Q

What initiates the heartbeat?

A
  • Cardiac centers in the reticular formation of the medulla oblongata initiate autonomic output to the heart
    • ANS does not initiate the heartbeat, it modulates rhythm and force
115
Q

Stroke Volume

  • List the 3 variables
A
  1. Preload
  2. Contractility
  3. Afterload
116
Q

Coronary Artery Disease (CAD)

  • What is it usually the result of?
A
  • A constriction of the coronary arteries
    • Usually the result of atherosclerosis
      • ​An accumulation of lipid deposits that degrade the arterial wall and obstruct the lumen
    • Endothelium damaged by hypertension, virus, diabetes, or other causes
117
Q

How do the heart valves operate?

A
  1. Atrioventricular valves open → atrioventricular valves close
  2. Semilunar valves open → semilunar valves close
118
Q

Chordae Tendineae

  • Description
  • Function
A
  • Cords that connect AV valves to papillary muscles on floor of ventricles
  • Prevent AV valves from flipping inside out or bulging into the atria when the ventricles contract
119
Q

Sinoatrial (SA) Node

  • Describe
A
  • A part of the conduction system
  • Pacemaker initiates each heartbeat and determines heart rate
    • Pacemaker in right atrium near base of superior vena cava
120
Q

Parasympathetic Nerve Pathway

  • List pathway steps
A
  1. Pathway begins with nuclei of the vagus nerves in the medulla oblongata (X cranial nerves)
    • Supplies the heart, lungs, upper digestive tract, and other organs of the chest and abdomen
  2. Fibers of right vagus nerve lead to the SA node
  3. Fibers of left vagus nerve lead to the AV node
  4. Little or no vagal stimulation of the myocardium
121
Q

Sinus Rhythm

A

Normal heartbeat triggered by the SA node

122
Q

Ectopic Focus

A
  • Another part of the heart that fires before the SA node
123
Q

Ectopic Foci

  • Description
  • Nodal rhythm
  • Intrinsic ventricular rhythm
A
  • Occur when myocardial cells located outside the SA node take over the normal pacemaker function of the SA node by becoming unusually “automatic”
    • Nodal rhythm
      • If SA node is damaged, heart rate is set by AV node, 40 to 50 bpm
    • Intrinsic ventricular rhythm
      • If both SA and AV nodes are not functioning, rate set at 20 to 40 bpm
  • Requires pacemaker to sustain life
124
Q

Arrhythmia

  • Description
  • What causes it?
A
  • Any abnormal cardiac rhythm
  • Failure of conduction system to transmit signals (heart block)
  • Types of heart blocks:
    • Bundle branch block
    • Total heart block (damage to AV node)
125
Q

Valvular Stenosis

A
  • Cusps are stiffened and opening is constricted by scar tissue
    • Result of rheumatic fever, autoimmune attack on the mitral and aortic valves
    • Heart overworks and may become enlarged
126
Q
A
127
Q

Mitral Valve Prolapse

A
  • Insufficiency in which one or both mitral valve cusps bulge into atria during ventricular contraction
    • Hereditary in 1 out of 40 people
    • May cause chest pain and shortness of breath
  • Which side of the heart will this be an issue? The systemic or pulmonary?
    • Whichever side of the heart the pulmonary valve is on is the side that has the problem with prolapse
129
Q

Atrioventricular (AV) bundle

  • Describe
A
  • A part of the conduction system
    • Bundle forks into right and left bundle branches
    • Branches pass through interventricular septum toward apex
130
Q

Purkinje fibers

  • Describe
A
  • A part of the conduction system
  • Nervelike processes that spread throughout ventricular myocardium
  • Signal passes from cell to cell through gap junctions
131
Q

Atrioventricular (AV) node

  • Describe
A
  • A part of the conduction system
  • Electrical gateway to the ventricles
    • Located near the right AV valve at lower end of interatrial septum
  • Fibrous skeleton—insulator prevents currents from getting to ventricles from any other route
132
Q

Right ventricular failure

A
  • ​Occurs when blood backs up in the vena cava causing systemic or generalized edema
    • Enlargement of the liver, ascites (pooling of fluid in abdominal cavity), distension of jugular veins, swelling of the fingers, ankles, and feet
  • Eventually leads to total heart failure
133
Q

Heart murmur

A

Abnormal heart sound produced by regurgitation of blood through incompetent valves

134
Q

Arteries

  • Function
A
  • Carry blood away from the heart
  • 99% carry oxygenated blood. The exception is the pulmonary artery/trunk
135
Q

Veins

  • Function
A
  • Carry blood back to the heart
  • 99% carry deoxygenated blood. Exception is the pulmonary vein
136
Q

Vessel Walls

  • List and describe the 3 layers of the vessel wall
A
  1. Tunica interna: lines the blood vessel and is exposed to blood
  2. Tunic media: middle layer
  3. Tunica externa: outermost layer
137
Q

Artery Types

  • List & describe
A
  • Conducting arteries (elastic or large arteries)
    • Biggest arteries
    • Examples: aorta, common carotid, subclavian, pulmonary trunk, common iliac arteries
  • Distributing (muscular or medium) arteries
    • Distributes blood to specific organs
    • Examples: brachial, femoral, renal, splenic
  • Resistance (small) arteries
    • Smallest arteries
    • Control amount of blood to various organs
  • Metarterioles
    • Short vessels that link arterioles to capillaries
    • Examples: muscle cells from a precapillary sphincter about entrance to capillary
138
Q

Aneurysm

  • Describe
  • Common sites
  • Common causes
A
  • Weak point in an artery or the heart wall
    • Forms a thin-walled, bulging sac that pulsates with each heartbeat and may rupture at any time
  • Common sites
    • Abdominal aorta
    • Renal arteries
    • Arterial circle at base of brain
  • Common cause is atherosclerosis and hypertension
139
Q

Capillaries

  • Description
  • Types & descriptions
A
  • Middle man between an artery and vein
  • Distinguished by ease with which substances pass through their walls and by structural differences that account for their greater or lesser permeability
  • Types
    1. Continuous capillaries
      • Occur in most tissues
    2. Fenestrated capillaries
      • Organs that require rapid absorption or filtration
      • kidneys, small intestine
    3. Sinusoids (discontinuous capillaries)
      • Irregular blood-filled spaces with large fenestrations
      • liver, bone marrow, spleen
140
Q

Capillary beds & pre-capillary sphincters

  • Description
A
  • Capillaries are organized into networks
  • Precapillary sphincters
    • Control which beds are well perfused
      • When sphincters open:
        • Capillaries are well perfused with blood and engage in exchanges with the tissue fluid
      • When sphincters closed:
        • Blood bypasses the capillaries
        • Flows through thoroughfare channel
  • 3/4 of the body’s capillaries are shut down at a given time
141
Q

Veins

  • List & describe the 5 types
A
  1. Postcapillary venules: smallest veins
  2. Muscular venules: up to 1 mm in diameter
  3. Medium veins: up to 10 mm in diameter
  4. Venous sinuses: Not capable of vasomotion
  5. Large veins: larger than 10 mm
    • Contains longitudinal bundles of smooth muscle
    • Venae cavae, pulmonary veins, internal jugular veins, and renal veins
142
Q

Varicose Veins

  • Describe
A
  • Occur when valves in veins stop working
  • Hemorrhoids are varicose veins of the anal canal
143
Q

Circulatory Routes

  • List the 6 routes
A
  • Simplest and most common route
  • Portal system
  • Anastomosis
  • Arterial anastomosis
  • Venous anastomosis (most common)
  • Arteriovenous anastomosis (shunt)
144
Q

Blood flow & perfusion

  • Description of each
A
  • Blood flow: the amount of blood flowing through an organ, tissue, or blood vessel in a given time (mL/min)
  • Perfusion: the flow per given volume or mass of tissue in a given time (mL/min./g)
  • At rest, total flow is quite constant, and is equal to the cardiac output (5.25 L/min)
145
Q

Blood pressure

  • Description
  • Measurement
  • Pressures recorded
A
  • The force that blood exerts against a vessel wall
  • Measured at brachial artery of arm using sphygmomanometer
  • Two pressures are recorded
    • Systolic pressure: peak arterial BP taken during ventricular contraction (ventricular systole)
    • Diastolic pressure: minimum arterial BP taken during ventricular relaxation (diastole) between heart beats
146
Q

Hypertension (2)

  • Description
  • Chronic hyperternsion
A
  • High blood pressure that can weaken small arteries and cause aneurysms
  • Chronic hyptertension is resting BP > 140/90
147
Q

Hypotension

  • Description
  • Caused by
A
  • Chronic low resting BP < 90/60
  • Caused by blood loss, dehydration, anemia
148
Q

Where is BP highest in relation to the heart?

A
  • BP is always higher in arteries closer to heart than in arteries farther away from the heart
149
Q

Peripheral resistance

  • Description
  • 3 variables of resistance
A
  • Opposition to flow that blood encounters in vessels away from the heart
  • 3 variables
    1. Blood viscosity (thickness)
    2. Vessel length
      • Pressure and flow decline with distance
    3. Vessel radius: most powerful influence over flow
      • Only significant way of controlling peripheral resistance
        • Vasoconstriction: by muscular effort that results in smooth muscle contraction
        • Vasodilation: by relaxation of the smooth muscle
150
Q

Blood velocity (speed) from aorta to capillaries

  • Increase or decrease?
  • Why?
A
  • Velocity decreases
  • 3 reasons
    1. Greater distance, more friction to reduce speed
    2. Smaller radii of arterioles and capillaries offers more resistance
    3. Farther from heart, the number of vessels and their total cross-sectional area become greater and greater
151
Q

Blood velocity (speed) from capillaries to vena cava

  • Increase or decrease?
  • Why?
A
  • Flow increases
  • Reasons
    • Decreased resistance going from capillaries to veins
    • Large amount of blood forced into smaller channels
    • Never regains velocity of large arteries
152
Q

Vasomotion

  • Description
  • 3 ways to control vasomotion
A
  • Altering blood pressure and flow via change in vessel radius
  • 3 ways of controlling vasomotion
    • Local control
    • Neural control
    • Hormonal control
153
Q

Local Control

  • Describe
  • List tpes
A
  • A form of controlling vasomotion
  • Local control types
    • Angiogenesis
    • Autoregulation
    • Reactive hyperemia
    • Vasoactive chemicals
154
Q

Neural Control

  • Describe primary & secondary roles
  • List 3 autonomic reflexes
A
  • A form of controlling vasomotion
  • Primary role
    • Adjust respiration to changes in blood chemistry
    • Under remote control by the CNS & ANS
  • Secondary role
    • Vasomotion
    • Vasomotor center of medulla oblongata exerts sympathetic control over blood vessels
      • Precapillary sphincters respond only to local and hormonal control due to lack of innervation
    • Integrating center for 3 autonomic reflexes
      • Baroreflexes
      • Chemoreflexes
      • Medullary ischemic reflex
155
Q

Anastomosis circulatory route

A
  • The point where two blood vessels merge
156
Q

Hormonal Control

  • What does hormone control influence?
  • How?
A
  • A form of controlling vasomotion
  • Hormones influence blood pressure
  • How?
    • Vasoactive effects
    • Regulating water balance
157
Q

Vasoconstriction & Vasodilation

  • Receptors they bind to
  • Blood vessels they bind to
A
  • A form of hormonal control
  • Vasoconstriction
    • Epinephrine
    • _​_Bind to a-adrenergic receptors
    • Most blood vessels
  • Vasodilation
    • Norepinephrine
    • Bind to b-adrenergic receptors
    • Skeletal and cardiac muscle blood vessels
158
Q

How does blood flow in response to changing priorities, to include exercise?

A
  • Arterioles shift blood flow with changing priorities
  • During exercise
    • Increased perfusion of lungs, myocardium, and skeletal muscles
    • Decreased perfusion of kidneys and digestive tract
159
Q

Capillary Exchange

  • Describe
  • 3 routes
  • Mechanisms
A
  • Two-way movement of fluid across capillary walls
  • Chemicals pass through via 3 routes
    1. Endothelial cell cytoplasm
    2. Intercellular clefts between endothelial cells
    3. Filtration pores (fenestrations) of the fenestrated capillaries
  • Mechanisms
    • Diffusion
    • Filtration
    • Reabsorption
    • Transcytosis
160
Q

Diffusion

  • Describe
  • Conditions required to occur
A
  • The most important form of capillary exchange
    • Glucose and oxygen diffuse out of the blood
    • CO2 and other waste diffuse into the blood
  • Conditions required to occur
    • The solute can permeate the plasma membranes of the endothelial cell; or
    • Find passages large enough to pass through
      • Filtration pores and intracellular clefts
161
Q

Transcytosis

A
  • Endothelial cells pick up material on one side of the plasma membrane by pinocytosis (cell-drinking, fluid endocytosis) or receptor-mediated endocytosis, transport vesicles across cell, and discharge material on other side by exocytosis
  • Important for fatty acids, albumin, and some hormones (insulin)
162
Q

Filtration & Reabsorption

  • Describe
  • List opposing forces
  • Capillary reabsorption
A
  • Fluid filters out of the arterial end of the capillary and osmotically reenters at the venous end
  • Opposing forces
    1. Blood hydrostatic pressure drives fluid out of capillary
      • High on arterial end of capillary, low on venous end
    2. Colloid osmotic pressure (COP) draws fluid into capillary
      • Oncotic pressure = net COP (blood COP − tissue COP)
    3. Hydrostatic pressure
      • Physical force exerted against a surface by a liquid
  • Capillaries reabsorb about 85% of the fluid they filter
    • Other 15% is absorbed by the lymphatic system and returned to the blood
163
Q

Edema

  • Description
  • 3 primary causes
A
  • The accumulation of excess fluid in a tissue
  • Occurs when fluid filters into a tissue faster than it is absorbed
  • 3 primary causes
    1. Increased capillary filtration
      • Kidney failure, histamine release, old age, poor venous return
    2. Reduced capillary absorption
      • Hypoproteinemia, liver disease, dietary protein deficiency
    3. Obstructed lymphatic drainage
      • Surgical removal of lymph nodes
164
Q

Edema Impact

  • List & describe the various types of edema/effects
A
  • Cerebral edema
    • Headaches, nausea, seizures, and coma
  • Pulmonary edema
    • Suffocation threat
  • Severe edema or circulatory shock
    • Excess fluid in tissue spaces causes low blood volume and low blood pressure
  • Tissue necrosis
    • Oxygen delivery and waste removal impaired
165
Q

Venous Return

  • Describe
  • List & describe mechanisms
A
  • The flow of blood back to the heart
  • Mechanisms
    1. Pressure gradient
      • Blood pressure is the most important force in venous return
      • 7 to 13 mm Hg venous pressure toward heart
      • Venules (12 to 18 mm Hg) to central venous pressure: point where the venae cavae enter the heart (~5 mm Hg)
    2. Gravity drains blood from head and neck
    3. Skeletal muscle pump in the limbs
      • Contracting muscle squeezed out of the compressed part of the vein
    4. Thoracic (respiratory) pump
      • Inhalation—thoracic cavity expands and thoracic pressure decreases, abdominal pressure increases forcing blood upward
        • Central venous pressure fluctuates
      • Blood flows faster with inhalation
    5. Cardiac suction of expanding atrial space
166
Q

Venous Return (2)

  • Impact on physical activity
A
  • Exercise increases venous return in many ways
    • Heart beats faster and harder, increasing CO and BP
    • Vessels of skeletal muscles, lungs, and heart dilate and increase flow
    • Increased respiratory rate, increased action of thoracic pump
    • Increased skeletal muscle pump
  • Venous pooling occurs with inactivity
    • Venous pressure not enough to force blood upward
    • With prolonged standing, CO may be low enough to cause dizziness
      • Prevented by tensing leg muscles, activate skeletal muscle pump
    • Jet pilots wear pressure suits
167
Q

Circulatory Shock (1)

  • Describe
A
  • When cardiac output is insufficient to meet the body’s metabolic needs
168
Q

Circulatory Shock (2)

  • 3 principal forms
A
  1. Hypovolemic shock (most common)
    • Loss of blood volume: trauma, burns, dehydration
  2. Obstructed venous return shock
    • Tumor or aneurysm compresses a vein
  3. Venous pooling (vascular) shock
    • Long periods of standing, sitting, or widespread vasodilation
169
Q

Circulatory Shock (3)

  • List & describe secondary forms
A
  • Anaphylactic shock
    • Severe immune reaction to antigen, histamine release, generalized vasodilation, increased capillary permeability
  • Cardiogenic shock
    • Inadequate pumping of heart (MI)
  • Low Venous Return (LVR)
    • Too little blood is returning to the heart
  • Neurogenic shock
    • Loss of vasomotor tone, vasodilation
    • Multiple causes from emotional shock to brainstem injury
  • Septic shock
    • Bacterial toxins trigger vasodilation and increased capillary permeability
170
Q

How does the body respond to circulatory shock?

  • List & describe the two responses
A
  • Compensated shock
    • Several homeostatic mechanisms bring about spontaneous recovery
    • Example: If a person faints and falls to a horizontal position, gravity restores blood flow to the brain
  • Decompensated shock
    • Triggers when the compensated shock mechanism fails
    • Life-threatening positive feedback loops occur
    • Condition gets worse causing damage to cardiac and brain tissue
171
Q

Blood flow & the brain

  • Description
  • Main chemical stimulous & list/describe methods
A
  • Regulates its own blood flow to match changes in BP and chemistry
  • Main chemical stimulus: pH
    • Hypercapnia
      • _​_CO2 levels increase in brain
      • Decreases pH, triggers vasodilation
    • Hypocapnia
      • Raises pH, stimulates vasoconstriction
      • Occurs with hyperventilation, may lead to ischemia, dizziness, and sometimes syncope
172
Q

Transient Ischemic Attacks (TIAs)

  • Describe
A
  • Brief episodes of cerebral ischemia
    • Caused by spasms of diseased cerebral arteries
    • Dizziness, loss of vision, weakness, paralysis, headache, or aphasia
    • Lasts from a moment to a few hours
    • Often early warning of impending stroke
173
Q

Stroke / Cerebral Vascular Accident (CVA)

A
  • Sudden death of brain tissue caused by ischemia
    • Atherosclerosis, thrombosis, ruptured aneurysm
  • Effects range from unnoticeable to fatal
    • Blindness, paralysis, loss of sensation, loss of speech common
  • Recovery depends on surrounding neurons, collateral circulation
174
Q

Veins of the head & neck

A
  • Large, thin-walled dural sinuses form between layers of dura mater
  • Drain blood from brain to internal jugular vein
  • Internal jugular vein receives most of the blood from the brain
    • Branches of external jugular vein drain the external structures of the head
  • Upper limb is drained by subclavian vein
175
Q

Which artery is most commonly used to determine BP?

A

Brachial artery

176
Q

Which artery is most commonly used to determine pulse?

A

Radial artery

177
Q

Where do branches to the lower limb arise from?

A
  • Branches to the lower limb arise from external iliac branch of the common iliac artery
178
Q

Hypertension (1)

  • Description
  • Why is it known as the silent killer?
  • Types
A
  • Most common cardiovascular disease affecting about 30% of Americans over 50
  • The silent killer
    • Major cause of heart failure, stroke, and kidney failure
      • Damages heart by increasing afterload
        • Myocardium enlarges until overstretched and inefficient
      • Renal arterioles thicken in response to stress
        • Drop in renal BP leads to salt retention (aldosterone) and worsens the overall hypertension
  • Types
    • Primary hypertension
      • Obesity, sedentary behavior, diet, nicotine
    • Secondary hypertension
      • Secondary to other disease
      • Kidney disease, hyperthyroidism
179
Q

Simplest and most common circulatory route

A
  • Heart → arteries → arterioles → capillaries → venules → veins
180
Q

Portal system circulatory route

A
  • Blood flows through two consecutive capillary networks before returning to heart
181
Q

Arteriovenous anastomosis (shunt) circulatory route

A
  • Artery flows directly into vein by passing capillaries
182
Q

Venous anastomosis (most common) circulatory route

A
  • One vein empties directly into another
183
Q

Arterial anastomosis circulatory route

A
  • Two arteries merge
184
Q

Dissecting aneurysm

  • Description
  • Cause
A
  • Occurs when blood accumulates between the tunics of the artery and separates them
  • Usually due to the degeneration of the tunica media​
185
Q

Angiogenesis

A
  • Form of local control
  • Growth of new blood vessels
    • Occurs in regrowth of uterine lining, around coronary artery obstructions, in exercised muscle, and malignant tumors
    • Controlled by growth factors
186
Q

Reactive hyperemia

A
  • Form of local control
  • If blood supply is cut off and then restored, blood flow increases above normal
187
Q

Vasoactive chemicals

A
  • Form of local control
  • Substances secreted by platelets, endothelial cells, and perivascular tissue to stimulate vasomotion
188
Q

Autoregulation

A
  • Form of local control
  • The ability of tissues to regulate their own blood supply
189
Q

Baroreflex

A
  • A form of neural control
  • An automatic, negative feedback response to changes in blood pressure
  • Important in short-term regulation of BP but not in cases of chronic hypertension
190
Q

Chemoreflex

A
  • A form of neural control
  • An automatic response to changes in blood chemistry
    • Especially pH, and concentrations of O2 and CO2
191
Q

Medullary ischemic reflex

  • Description
A
  • A form of neural control
  • Automatic response to a drop in perfusion of the brain
    • Activates corrective reflexes when it senses ischemia (insufficient perfusion)
    • Cardiac and vasomotor centers send sympathetic signals to heart and blood vessels
      • Increases heart rate and contraction force
      • Widespread vasoconstriction
      • Raises BP and restores normal perfusion to the brain

BIO 151 A&P II (8 decks)

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