The Cardiovascular System II: Blood, Blood Pressure, and Auscultation

What are the two components of whole blood?

Plasma and formed elements

What is the average percentage of plasma?

55%

What is the average percentage of formed elements?

45%

What percent of formed elements are erythrocytes?

99.9%

What is the basic function of erythrocytes?

To carry oxygen throughout the body

What percentage of the formed elements are leukocytes and platelets?

0.1%

What protein in red blood cells binds to oxygen?

Hemoglobin

What ion is the oxygen binding site?

Iron (Fe)

What color is produced when oxygen binds to the above ion?

Bright red

Why measure hemoglobin concentration in red blood cells?

To see how well a person carries oxygen in their blood.

What is the normal shape of a red blood cell?

A flat/Biconcave disk

What is a complete blood count (CBC)?

A blood sample test measuring amounts of formed elements and hemoglobin concentration

What four basic measurements are made of CBC?

1) Amounts/Characteristics of red blood cells

2) Total amounts of white blood cells

3) Percentage of each type of WBC

4) Amount hemoglobin

What instrument is used to produce a modern CBC?

Hemotology analyzer

Why are CBCs performed?

Check overall health, scan for/check on medical condition, or check on medical treatment impact

What signs in a CBC indicate anemia?

Low RBC High Hb Low HCT

What signs in a CBC indicate leukemia?

Higher than normal wbc count

What is hematocrit?

The percentage of whole blood volume composed of red blood cells

What is considered an average hematocrit for females?

Approximately 42%

What is considered an average hematocrit for males?

Approximately 47%

Why is hematocrit so close to % of formed elements?

Because RBCs make up 99.9% of the formed elements

Why is hematocrit typically higher in males than in females?

Males generally have higher testosterone levels, which stimulate erythropoiesis

Why measure hematocrit?

To evaluate oxygen-carrying capacity and diagnose anemia or polycythemia

What is hypoxia?

Insufficient oxygen concentration to maintain homeostasis in the body’s tissue.

What are the consequences of prolonged hypoxia?

Can damage tissue and the organs those tissues make up.

What is hypoxemia?

Insufficient oxygen concentration in the blood.

What is the difference between hypoxia and hypoxemia?

Hypoxemia refers to low oxygen in blood, while hypoxia refers to low oxygen in tissues

What is anemia?

A reduction in the blood’s ability to carry oxygen.

What two measurements would you take to detect anemia?

Hemoglobin concentration and hematocrit

What are the types of anemia and their causes?

Hemorrhagic anemia: Excessive blood loss

Sickle cell anemia: Mutation in the gene for hemoglobin

Aplastic anemia: Malfunction of bone marrow production of erythrocytes

Pernicious anemia: Vitamin B12 deficiency

What are the 4 ABO blood types?

A, B, AB, O

What is/are the name of the antigen(s) responsible for blood type A?

A antigen

What type(s) of antibodies (if any) does a blood type A person produce?

Anti-B antibodies

What is/are the name of the antigen(s) responsible for blood type B?

B Antigen

What type(s) of antibodies (if any) does a blood type B person produce?

Anti-A antibodies

What is/are the name of the antigen(s) responsible for blood type AB?

A and B antigens

What type(s) of antibodies (if any) does a blood type AB person produce?

None

What is/are the name of the antigen(s) responsible for blood type O?

None

What type(s) of antibodies (if any) does a blood type O person produce?

Anti A and Anti B antibodies

What is agglutination?

Clumping of red blood cells due to antibody-antigen interaction

Explain how we determined blood type in lab.

By mixing synthetic blood with Anti-A, Anti-B, and Anti-D antibodies. Agglutination indicates presence of corresponding antigen.

Know all the possible agglutination combinations and what blood types they indicate.

Agglutination with A only → Type A

Agglutination with B only → Type B

Agglutination with A and B → Type AB

No agglutination → Type O

Agglutination with D → Rh+

No agglutination with D → Rh–

What is Rh factor?

Another RBC surface antigen (D protein)

What is the name of the antigen responsible for Rh+?

D- Antigen

What is the Rh- person missing that the Rh + person has?

The D antigen

What does the Rh- person produce that the Rh+ person does not?

Anti-D antibodies

Define auscultation

Medical/Physical examination where the examiner often listens to internal sounds from the patients body using a stethoscope.

Describe systolic pressure

Pressure in arteries during heart contraction

What is considered normal systolic pressure?

~120 mmHg

Describe diastolic pressure

Pressure in arteries during heart relaxation

What is considered normal diastolic pressure?

~80 mmHg

Describe how to measure blood pressure with a stethoscope and sphygmomanometer.

Inflate cuff above systolic pressure to stop flow → slowly release while listening for first sound (systolic) → continue until sound disappears (diastolic)

When do you record diastolic pressure?

When the Korotkoff sounds disappear

When do you record systolic pressure?

When the Korotkoff sounds first appear

Know how to calculate pulse pressure.

Systolic – Diastolic

What is considered a normal pulse pressure?

~40 mmHg

What does a pulse pressure greater than 60 mmHg indicate?

Arterial stiffness or risk of cardiovascular disease

What two factors alter pulse pressure?

Stroke volume and arterial compliance

Know how to calculate mean arterial pressure.

MAP = Diastolic + (Pulse Pressure / 3)

What factors alter mean arterial pressure?

Heart rate, stroke volume, and peripheral resistance

What is mean arterial pressure?

Average pressure in arteries during one cardiac cycle

What are the two major heart sounds?

S1 (“lub”) and S2 (“dub”)

What are the four heart sound positions?

Aortic, Pulmonic, Tricuspid, Mitral

What event causes the 1st heart sound (S1), the "lub"?

Closure of the AV valves (tricuspid and mitral)

Which position(s) allow you to hear the S1 best?

Tricuspid and Mitral positions

What is a split S1?

Slight difference in closing time of AV valves

What is the first sound of a split S1 called?

M1

What produces the first sound of a split S1?

Closure of the mitral valve

What is the second sound of a split S1 called?

T1

What produces the second sound of a split S1?

Closure of the tricuspid valve

In what heart sound position(s) would you hear the split S1 best?

Tricuspid position

What event causes the 2nd heart sound (S2), the "dub"?

Closure of semilunar valves (aortic and pulmonary)

Which position(s) allow you to hear the S2 best?

Aortic and Pulmonic positions

What is a split S2?

Delay in closure of the pulmonary valve compared to the aortic valve

What is the first sound of a split S2 called?

A2

What produces the first sound of a split S2?

Closure of the aortic valve

What is the second sound of a split S2 called?

P2

What produces the second sound of a split S2?

Closure of the pulmonary valve

At what heart sound position(s) would you hear the split S2 best?

Pulmonic area

What can your patient do to cause you to hear a split S2 normally? Explain why this causes a split S2.

Inhale deeply. Inhalation increases venous return to the right heart, delaying pulmonary valve closure

What is a heart murmur?

Abnormal heart sound due to turbulent blood flow

What is a systolic murmur?

Murmur between S1 and S2 (during systole)

When do systolic murmurs appear?

Between S1 and S2

What is a diastolic murmur?

Murmur between S2 and the next S1 (during diastole)

When do diastolic murmurs appear?

Between S2 and the next S1

What three anatomical abnormalities can cause heart murmurs?

Valve stenosis, valve insufficiency, holes in the septum (atrial or ventricular)