Lab 13, 14, 15 - Blood Typing, ECG, Blood Pressure

Flashcards covering key concepts from Labs 13, 14, and 15 focused on blood typing, electrocardiography, and blood pressure.

What determines your ABO blood type?

The presence or absence of A and B antigens on red blood cells.

What determines your Rh blood type?

The presence (+) or absence (–) of the D antigen on RBCs.

What are antigens?

Proteins or glycoproteins on the surface of RBCs that trigger an immune response.

What are antibodies?

Proteins in plasma that recognize and bind to specific antigens, causing agglutination.

What antibodies are found in Type A blood?

Anti-B antibodies.

What antibodies are found in Type B blood?

Anti-A antibodies.

What antibodies are found in Type AB blood?

None — Type AB has no anti-A or anti-B antibodies.

What antibodies are found in Type O blood?

Both anti-A and anti-B antibodies.

When do people have anti-D (Rh) antibodies?

Only if they are Rh– and have been exposed to Rh+ blood.

What happens if mismatched blood is transfused?

Agglutination (clumping) occurs, which can be fatal.

Who can Type A blood donate to?

Type A and Type AB.

Who can Type A receive from?

Type A and Type O.

Who can Type B blood donate to?

Type B and Type AB.

Who can Type B receive from?

Type B and Type O.

Who can Type AB donate to?

Only Type AB.

Who can Type AB receive from?

Everyone — universal recipient.

Who can Type O donate to?

Everyone — universal donor.

Who can Type O receive from?

Only Type O.

What safety precautions should be followed when handling blood samples?

Wear gloves, goggles, and lab coat; disinfect benches; dispose of sharps in hazardous containers; wash hands after lab.

What indicates blood agglutination in typing tests?

Clumping in the sample when exposed to specific antibody serum.

What initiates the electrical impulse in the heart?

The sinoatrial (SA) node.

What is the function of the SA node?

It acts as the heart’s natural pacemaker.

What happens after the SA node fires?

The impulse spreads through both atria, causing atrial contraction.

What is the function of the AV node?

It delays the signal to allow the atria to contract before the ventricles.

What is the AV bundle (bundle of His)?

A pathway that conducts impulses from the AV node to the bundle branches.

What are Purkinje fibers?

Nerve fibers that distribute impulses throughout the ventricles for contraction.

What is an ECG?

A recording of the heart’s electrical activity over time.

What forms Einthoven’s triangle?

Electrodes on the right arm, left arm, and left leg.

What does the P wave represent?

Atrial depolarization.

What does the QRS complex represent?

Ventricular depolarization.

What does the T wave represent?

Ventricular repolarization.

What is the P–R interval?

The time from the start of atrial depolarization to the start of ventricular depolarization.

What happens to heart rate when the R–R interval decreases?

Heart rate increases.

Which waveform changes the most when heart rate increases?

The T–P segment.

What is a normal duration for a QRS complex?

Less than 0.12 seconds.

What is the Q–T interval?

Time from the start of ventricular depolarization to the end of ventricular repolarization.

How do you calculate heart rate from an ECG?

Divide 60 by the R–R interval in seconds.

How are intervals and segments different on an ECG?

An interval includes at least one wave and a flat line, while a segment includes only the flat portion between waves.

If the heart rate increases, what would you expect to see in the ECG?

The R–R interval decreases.

What is blood pressure?

The force of blood against the inside of blood vessel walls.

What causes blood to move through vessels?

A pressure gradient — blood moves from high to low pressure.

What three main factors influence blood pressure?

Cardiac output, peripheral resistance, and blood volume.

What is systolic pressure?

The maximum arterial pressure during ventricular contraction.

What is diastolic pressure?

The minimum arterial pressure during ventricular relaxation.

What tool is used to measure blood pressure?

A sphygmomanometer and a stethoscope.

What are Korotkoff sounds?

The sounds heard in an artery as pressure is released from the cuff.

When is systolic pressure recorded?

When Korotkoff sounds are first heard.

When is diastolic pressure recorded?

When Korotkoff sounds are no longer heard.

How should the blood pressure cuff be positioned?

Tubes facing anterior and exiting toward the hand.

Why should the cuff not be inflated more than 20–30 mmHg above the expected value?

Overinflation may cause injury to the patient.

What is normal adult blood pressure?

Around 115/70 mmHg.

What do the two numbers in a blood pressure reading represent?

Systolic (top) and diastolic (bottom) pressures.

What is hypertension?

Chronically elevated blood pressure above 130/80 mmHg.

What is hypotension?

Chronically low blood pressure below 90/60 mmHg.

Why does blood pressure increase during exercise?

To ensure adequate oxygen supply to muscles.

Why does blood pressure lower after exercise?

Oxygen demand decreases and vessels relax.

What happens to blood when you stand up compared to lying down?

Blood pools in the lower limbs due to gravity.

What happens to blood pressure when moving from standing to lying down?

It decreases in the lying position.