Cardiovascular System Overview

Flashcards covering key concepts from the cardiovascular system, including structure, function, and regulation.

What are the main components of the cardiovascular system?

The heart, blood vessels, and blood.

What is the function of contractile cardiocytes?

Responsible for the heart's pumping action.

What do autorhythmic cardiocytes do?

Generate electrical impulses that initiate and regulate heartbeats.

Describe the pathways of blood flow in the pulmonary circuit.

Blood flows from the right side of the heart to the lungs via pulmonary arteries for gas exchange, and returns to the left side of the heart through pulmonary veins.

What is the function of the atrioventricular (AV) node?

Delays electrical conduction from the atria to the ventricles, allowing time for atrial contraction.

What is the composition of the heart wall?

The heart consists of three layers: epicardium, myocardium, and endocardium.

How do valves function in the heart?

Valves ensure unidirectional blood flow by opening and closing based on pressure gradients.

What is the role of the sinoatrial (SA) node?

Acts as the primary pacemaker of the heart, generating electrical activity.

What occurs during the isovolumetric contraction phase of the cardiac cycle?

Ventricular muscles contract while all valves are closed, increasing ventricular pressure.

Define cardiac output (CO).

The volume of blood pumped by the heart per minute.

How is stroke volume (SV) calculated?

SV = End-Diastolic Volume (EDV) - End-Systolic Volume (ESV).

What is the ejection fraction (EF)?

The percentage of EDV that is ejected during a heartbeat.

What influences vascular resistance?

Vessel radius, vessel length, and blood viscosity.

What is the primary function of arterioles?

Regulate blood flow into capillary beds.

How do sympathetic and parasympathetic systems affect heart rate?

Sympathetic increases heart rate, while parasympathetic decreases it.

What are the Starling forces involved in capillary exchange?

Hydrostatic pressure and osmotic pressure.

What is the significance of mean arterial pressure (MAP)?

It’s the average pressure in a person's arteries during one cardiac cycle, crucial for organ perfusion.

What mechanisms assist in venous return?

Skeletal muscle pump and respiratory pump.

What is reactive hyperemia?

Increased blood flow that occurs after a period of occlusion.

Describe the myogenic response of arterioles.

Vessels adjust for stretch; increased pressure triggers muscle contraction to prevent excessive dilation.

What is the effect of norepinephrine on arteriolar tone?

It causes vasoconstriction, increasing vascular resistance and blood pressure.