Ch. 13 - Blood, Heart, Circulation

What are the functions of the circulatory system?

1. Transportation; respiratory gases, nutrients, immune cells

2. Regulation of hormones and temperature (vasodilation/contrstriction)

3. Protecting; blood clotting

What are the 3 components of the cardiovascular system?

• Blood

• Blood vessels

• Heart

What is centrifuged blood?

• Blood that has been spinned fast to separate components of blood by weight

What are the components of blood from heaviest to lightest?

1. RBCs (heaviest)

2. WBC’s/platelets

3. Plasma

How much of formed elements in blood? Plasma?

• Formed elements; 45%

• Plasma; 55%

Where does arterial blood go and what is its color? The exception?

• Leaving heart, bright red oxygenated blood

except pulmonary arteries carrying blood lungs

Where does venous blood go and what is its color? The exception?

• Entering heart, dark red deoxygenated (less) blood

except pulmonary veins carrying blood to heart

What is plasma? What is is made up of?

• Fluid that pushes blood cells throughout body

• Made up of; water and dissolved solutes (ions)

What are the two proteins that make up plasma?

• Albumin

• Fibrinogen 

What is the function of albumin?

• Creates osmotic pressure by drawing water from tissues maintaining BV and pressure

What is the function of fibrinogen?

• Helps in clotting after becoming fibrin (helps platelets)

What does plasma volume determine?

• Determines/shows hydration and other health factors 

How do osmoreceptors relate to plasma volume?

• Cause release of ADH in plasma; retaining hydration 

What is the shape of erythrocytes. What cellular structures do they lack?

Red blood cells

• Flattened biconcave discs; lack nuclei and mitochondria

What is the lifespan of erythrocytes? What removes them?

RBCs

• 120 days; removed by phagocytic cells

What protein are RBCs made up of? Its function?

• Hemoglobin: stores Fe for O2 binding

What units are hemoglobin made up of? What is attached to it that allows for O2 binding?

• 4 Heme units; contain Fe for O2 binding

What is the function of erythrocytes (RBCs)?

• Carry/hold on to O2 and release when needed

In red blood cells with high concentration of O2, what happens in high vs low pressure?

• High pressure; keeps O2

• Low pressure; releases O2

In red blood cells with low concentration of O2, what happens in high vs low pressure?

• High pressure; pick up O2

• Low pressure; can’t pick up

What is anemia?

• Abnormally low hemoglobin or RBC count

What are the two types of anemia?

MANY other types

• Iron deficiency anemia (most common)

• Pernicious anemia

What is iron deficiency anemia?

• Insufficient iron in hemoglobin of RBC not allowing RBC to transport O2

What is pernicous anemia?

• Lack of intrinsic factor (vitamin B12) preventing sufficient production of RBCs

What is the function of leukocytes?

White blood cells

• Defend against infection

What are the divisions of leukocytes?

WBCs

• Granulocytes; visible dots/granules

• Agranulocytes;  granules not visible

What are the types of granulocytes?

1. Neutrophils 

2. Basophils

3. Eosinophils 

What is the function of neutrophils?

• Phagocytic cells

What is the function of eosinophils?

• Detoxifies foreign substances, secretes enzymes that dissolve clots, fights parasitic infections

What are the two functions of basophils?

• Release histamine during inflammation

• Release anticoagulant heparin 

What are the types of agranulocytes?

1. Monocytes

2. Lymphocytes

What is the function of monocytes?

• Phagocytic cells

What is the function of lymphocytes?

• Provide specific (adaptive) immune response using antibodies

What is the function of platelets? What does it release?

• Platelets (cytoplasmic fragments): enables clotting, releasing serotonin causing vasoconstriction

What are antigens and their function?

• Extensions on surface of cells; to help immune system recognize its own cells

When are antibodies produced?

• Produced by lymphocytes in response to foreing antigens

What is the ABO system?

• Antigens on erythrocyte cell surface

What antigen does Type A blood have? Antibodies in plasma?

• Antigen A (IA); anti-B antiobodies in plasma 

What antigen does Type B blood have? Antibodies in plasma?

• Antigen B (IB); anti-A antibodies in plasma

What antigen does Type AB blood have? Antibodies in plasma?

• Has both A and B antigens (IAIB); has no antibodies in plasma 

UNIVERSAL RECIPIENT 

What antigen does Type O blood have? Antibodies in plasma?

• Has neither A nor B antigens; has both A and B antibodies in plasma

UNIVERSAL DONOR

When does a transfusion reaction occur? What occurs?

• Person receiving the wrong blood type; antibodies binding to erythrocytes causing agglutination 

What antigen does the Rh factor contain?

• Antigen D or Rho(D)

What does an Rh positive person’s blood contain?

• Contains antigen D or Rho(D)

person can receive Rh+ and Rh- blood

What does an Rh negative person’s blood not contain?

• Does not contain antigen D or Rho(D)

person can only receive Rh- blood

When may a Rh- person be exposed to Rh+ blood?

• Blood transfusion or pregnancy

How can Rh- negative mother experience issue with Rh+ blood?

• Rh- negative mother; exposed to Rh+ fetal blood producing antibodies

How will Rh+ fetal blood affect future pregnancies?

• Causes Erythroblastosis fatalis; causing antibodies to attack future Rh+ fetus’s blood 

What is the function of arteries?

• Carry oxygenated blood AWAY from heart

What is the function of arterioles?

• Control blood flow through capillaries using vasoconstriction and vasodilation

What is the function of capillaries?

• Where gases and nutrients are exchanged between blood and tissues

What is the function of venules?

• Collect blood from capillaries 

What is the function of veins?

• Returning deoxygenated blood back to the heart

In what blood vessel is most of the total blood volume located?

• Veins

What occurs in the right atrium?

• Receives deoxygenated blood from body

What occurs in the right ventricle?

• Pumps deoxygenated blood into the lungs

What occurs in the left atrium?

• Receives oxygenated blood from the lungs

What occurs in the left ventricle?

• Pumps oxygenated blood into the body

What are the right and left sides separated by in the heart?

• Septum 

What is the function of the septum?

• Prevents mixing of O2 rich and O2 poor blood

What is the function of the fibrous skeleton? What do they form?

• Separates atria from ventricles; allow atria to work as 1 unit and ventricles to work as a separate unit

form Annuli rings

What does the pulmonary circuit involve?

• Between heart and lungs

What are the functions of the pulmonary arteries and veins?

• Pulmonary arteries; pumps deoxygenated blood to lungs

• Pulmonary veins; returns oxygenated blood to heart

What does the systemic circuit involve?

• Between heart and body

What are the functions of the aorta and superior/inferior vena cava?

• Aorta: pump oxygenated blood to the body

• Superior/inferior: return deoxygenated blood to heart

What are the atrioventricular valves? Where are they located?

• Tricuspid valve: between RIGHT atria and ventricle

• Bicuspid (mitral) valve: between LEFT atria and ventricle

What is the function of the papillary muscles and chordae tendina surrounding the heart?

• Prevent valves from everting

What are the semilunar values? Where are they located?

• Pulmonary valve; between right ventricle and pulmonary trunk

• Aortic valve; between left ventricle and aorta

What is the pathway of blood from the heart to the lungs (pulmonary circuit)?

1. Superior/Inferior Vena Cava

2. Right atrium

3. Tricuspid valve

4. Right ventricle

5. Pulmonary valve

6. Pulmonary trunk to pulmonary artery 

What is pathway of blood from the lungs back to the heart (systemic circuit)?

1. Pulmonary veins

2. Left atrium

3. Bicuspid (mitral) valve

4. Left ventricle

5. Aortic Valve

6. Aorta 

What is generally a heart murmur caused by?

• Abnormal blood flow; defective heart valves

What is mitral stenosis?

Type of Heart Murmur

• Mitral valve calcifies and impairs flow between left atrium and ventricle; resulting hypertension

What is the cardiac cycle?

• Repeated pattern of contraction and relaxation

What is systole? Diastole?

• Systole: contraction of the heart (lub)

• Diastole: relaxation of the heart(dub)

What are sounds produced by the closing of valves?

• Lub

• Dub

What causes the “lub” sound of the heart? What is this called?

• Closing of AV valves; ventricular systole

What causes the “dub” sound of the heart? What is this called?

• Closing of semilunar valves; ventricular diastole

What is end diastolic volume?

• Total volume of blood in ventricles at the end of diastole

What is end systolic volume? How much blood left here in comparison to end diastole volume?

• Amount of blood left in left ventricle after systole

1/3 of diastolic volume 

What is pressure’s role in the cardiac cycle?

• Provides force needed to open valves and pump blood

What is the first step of the pressure changes in the cardiac cycle?

1. Ventricles begin contraction pressure rising; AV valves close “lub”: isovolumetric contraction

What is the second step of the pressure changes in the cardiac cycle?

2. Pressure builds; semilunar valves open pushing blood into arteries

What is the 3rd step of the pressure changes in the cardiac cycle?

3. Pressure in ventricles falls; semilunar valves close “dub”: isovolumetric relaxation

What is the 4th step of the pressure changes in the cardiac cycle?

4. Pressure in ventricles fall below atria, opening AV values filling ventricle with blood left

to balance out pressure in heart

What is the 5th step of the pressure changes in the cardiac cycle?

5. Atria contracting sending last of blood to ventricles

What are cardiac muscle cells connected by?

• Connected by gap junctions called intercalated discs

What does the myocardium/functional synctium allow the heart to do?

• Allow heart to contract from one stimulation event

What is automaticity of the heart?

• Automatic heart beat, rhythm

What are the main conducting tissues of the heart?

1. Sinoatrial node; pacemaker

2. AV node

3. Bundle of His

4. Bundle branches 

5. Purkinje fibers

What is the first step of conduction in the heart?

1. AP from SA node (pacemaker) spreads over atria

What is the second step of conduction in the heart? What does it stimulate?

2. SA sends signal to AV node stimulating atrial contraction

lagging here toe ensure all blood has been pumped into ventricles

What is the 3rd step of conduction in the heart?

3. AV node spreads signal to bundle of His towards ventricles 

What is the 4th step of conduction in the heart?

4. Bundle of His spreads signal to bundle branches

What is the 5th step of conduction in the heart? What does this stimulate?

5. Bundle branches spread signal to purkinje fibers stimulating ventricular contraction

What does a electrocardiograph (ECG) record?

• Records electrical activity of heart by picking up movements of ions in tissues (depolarization) in response to events

Does an ECG record contraction and relaxation itself?

• No, only records electrical activity

What is the order of ECG waves and intervals?

1. P wave

2. P-Q interval

3. QRS wave

4. S-T interval/segment

5. T wave

What occurs in the P wave in relation to electrical conduction?

1. Atrial depolarization; SA node spreading signal over atria (atrial contraction)

What occurs in the P-Q interval in relation to electrical conduction?

2. SA node signaling AV node; AV nodal delay

ensures all blood has been pumped out

What occurs in the QRS wave in relation to electrical conduction? Why is there a larger peak here?

3. Ventricular depolarization; AV node’s bundle of His and bundle branches signaling ventricles 

larger peak; needs more force to pump blood out