Untitled Flashcards Set

Pericardium

Fibrous, double-layer serous membrane surrounding the heart; secretes fluid to reduce friction.

Myocardium

Heart muscle (cardiac muscle).

Atria

Receiving chambers of the heart (Left and Right).

Ventricles

Pumping chambers of the heart (Left and Right).

Vena Cava

Carries low O₂ blood to the right atrium.

Pulmonary Trunk

Carries low O₂ blood to the lungs; splits into right and left pulmonary arteries.

Aorta

Carries high O₂ blood to the body from the left ventricle.

Pulmonary Veins

Carry high O₂ blood from the lungs to the left atrium.

SA Node (Sinoatrial Node)

The pacemaker of the heart; sets the rhythm of the heartbeat (~100 bpm).

AV Node (Atrioventricular Node)

Slows the electrical signal, allowing atria to fully contract.

AV Bundle (Bundle of His)

Transmits signal from atria to ventricles.

Purkinje Fibers

Spread the action potential throughout the ventricles.

P Wave

Represents atrial depolarization (atria contracting).

QRS Complex

Represents ventricular depolarization (ventricles contracting).

T Wave

Represents ventricular repolarization (ventricles relaxing).

Systole

Contraction phase of the cardiac cycle (blood is pumped out).

Diastole

Relaxation phase of the cardiac cycle (heart fills with blood).

EDV (End Diastolic Volume)

Volume of blood in the heart after relaxation and filling.

ESV (End Systolic Volume)

Volume of blood left in the heart after contraction and ejection.

Stroke Volume (SV)

Volume of blood ejected from the ventricles per heartbeat.

Cardiac Reserve

The difference between max cardiac output during exercise and resting cardiac output.

Norepinephrine

Increases heart rate at the SA node and AV node, increases contractility.

Acetylcholine

Decreases heart rate but has no effect on contractility.

Proprioceptors

Detect movement and send information to the Cardiovascular Center.

Chemoreceptors

Detect CO₂ and O₂ levels in the blood.

Baroreceptors

Detect blood pressure.

Epinephrine

Hormone that increases heart rate and contractility.

Thyroid Hormones

Increase heart rate and contractility.

What is the difference between systole and diastole?

Systole = Contraction, Diastole = Relaxation.

Where does the SA node send the electrical impulse next?

To the AV node.

What does the T wave on an ECG represent?

Ventricular repolarization (ventricles relaxing).

Which valve is found between the left atrium and left ventricle?

The bicuspid (mitral) valve.

What is the primary fuel used by cardiac muscle cells during rest?

Fatty acids.