Circulatory System and Cardiac Physiology

Flashcards covering key terms and concepts related to the circulatory system and cardiac physiology.

Pulmonary circulation

Loops of blood vessels between the heart and lungs.

Systemic circulation

Circuit of blood vessels between the heart and other body systems.

Cardiac cycle

The cycle of blood flow in the heart, characterized by alternating contractions and relaxations.

Atrioventricular valve

Valve between the atrium and ventricle (e.g., tricuspid and bicuspid valves) that prevents backflow during contraction.

S1 heart sound

Sound produced by the closing of the atrioventricular valves; signifies the beginning of ventricular contraction.

S2 heart sound

Sound produced by the closing of the semilunar valves; signifies the end of ventricular contraction.

Cardiac conduction pathway

Pathway that triggers heart contractions; includes the SA node and AV node.

Pacemaker potential

The gradual depolarization of pacemaker cells (SA node) that leads to action potentials.

Funny channels

Sodium channels that are leaky and allow sodium to flow into the SA node cells, contributing to pacemaker activity.

Absolute refractory period

Time during which the heart cannot be depolarized again until it repolarizes.

ECG (Electrocardiogram)

A recording of the electrical activity of the heart used to diagnose heart conditions.

Junctional rhythm

Heart rhythm that occurs when the SA node is non-functional and the AV node paces the heart.

Ventricular fibrillation

A chaotic and irregular heart rhythm with no organized pattern.

Cardiac myocytes

Heart muscle cells that transmit signals but do not contract.

Cardiac action potential

The electrical impulse that triggers heart muscle contraction, lasting about 200 milliseconds.

AV nodal delay

Delay in conduction through the AV node to allow for effective filling of the ventricles.

Cardiomyopathy

Disease of the heart muscle that can affect its size, shape, and ability to pump blood.

Hypokalemia

Low potassium levels in the blood, which can affect heart rhythm.

ST segment

Part of the ECG that indicates the time between ventricular depolarization and repolarization.

junctional rhythm

• SA node non functional

• P- wave absent 

• Paced by AV nod e

• QRS complex and T-wave is bigger 

• Needs pacemaker

heart blockage

p-wave is not conducted to AV nide, more p-wave than QRS complex

ventricular fibrillation

• Chaotic and irregular 

• Heart is quivering- no pattern 

• shock the heart

complete heart block

• Number of p waves does not match number of QRS complex 

• Atrium pumping twice as much as ventricles

cardiomyopathy

• ST elevated myocardial infarction 

• ST system does not reset 

• QRS and T Wave are linked

  • Depolarizes and repolarizes- heart cramps 

  • Heart stops

major heart attack - widow maker

• Cannot be shocked- heart is already cramped 

• Need epinephrine, morphine,and atropine

  • Administered quickly in under 3 minutes