Cardiovascular System — General Characteristics, Heart Structure, Blood Vessels, and Regulation

A comprehensive set of practice flashcards covering the major concepts from the lecture on the cardiovascular system, including heart structure, vessels, blood flow, regulation, and common clinical topics.

What are the two primary components of the cardiovascular system, and what is the heart's main function?

The heart and blood vessels; the heart is a hollow, cone-shaped muscular pump that generates force to transport respiratory gases, nutrients, and wastes throughout the body.

What are the three types of blood vessels and their main roles?

Arteries carry blood away from the heart; veins carry blood toward the heart; capillaries exchange nutrients, gases, and wastes between blood and tissues.

What are the two closed circuits in the cardiovascular system, and what does each circuit do?

Pulmonary circuit carries blood from the heart to the lungs for gas exchange and back to the heart; systemic circuit transports oxygen-rich blood to body tissues and returns wastes to the heart.

Which side of the heart pumps to the pulmonary circuit, and which pumps to the systemic circuit?

Right side to the pulmonary circuit; left side to the systemic circuit.

Where is the heart located and how big is it?

Located in the mediastinum of the thoracic cavity, about the size of a fist (roughly 14 cm long and 9 cm wide).

What are the coverings of the heart, including the fibrous, parietal, and visceral pericardium?

Pericardium covers the heart and proximal ends of large vessels; fibrous pericardium is the tough outer layer; parietal pericardium is the outer serous layer; visceral pericardium (epicardium) is the inner serous layer attached to the heart; there is a pericardial cavity between parietal and visceral layers.

What are the three layers of the heart wall and their principal roles?

Epicardium (outer, visceral pericardium; reduces friction); Myocardium (middle, cardiac muscle; contracts to pump); Endocardium (inner lining of chambers and valves).

What are the four chambers of the heart and their general functions?

Atria (thin-walled upper chambers that receive blood) and ventricles (thick-walled lower chambers that pump blood); auricles are flap-like projections from the atria.

What structures separate the atria from the ventricles and separate the right and left sides of the heart?

Interatrial septum separates the atria; Interventricular septum separates the ventricles.

Which valves separate the atria from the ventricles, and which separate the ventricles from the great arteries?

Tricuspid and mitral valves separate atria from ventricles; pulmonary and aortic semilunar valves separate ventricles from the pulmonary trunk and aorta.

What are chordae tendineae and papillary muscles, and what is their function?

Chordae tendineae attach the AV valve cusps to papillary muscles to prevent cusps from bulging into the atria during ventricular contraction.

What is the skeleton of the heart, and what is its function?

Dense connective tissue rings around vessel origins and valve openings; provide attachments for valves and muscle fibers and prevent excessive dilation; forms the fibrous skeleton of the heart.

Name the major coronary arteries and one key branch for each.

Right coronary artery (RCA) and Left coronary artery (LCA); RCA gives posterior interventricular and right marginal branches; LCA gives circumflex and anterior interventricular (left anterior descending) branches.

Where do cardiac veins drain, and where do they drain into?

Cardiac veins drain into the coronary sinus, which drains into the right atrium.

What are the major components of the Cardiac Conduction System, in order from the pacemaker outward?

SA node (pacemaker) → internodal atrial pathways → AV node → AV bundle (His) → left and right bundle branches → Purkinje fibers; coordinates atrial and ventricular contraction.

What are the main waves in the ECG and what do they represent?

P wave: atrial depolarization; QRS complex: ventricular depolarization; T wave: ventricular repolarization; atrial repolarization is hidden in the QRS.

What do S1 (lubb) and S2 (dupp) heart sounds correspond to?

S1: closure of the AV valves during ventricular systole; S2: closure of the semilunar valves during ventricular diastole; murmurs are abnormal sounds from incomplete valve closure.

What is the difference between systole and diastole?

Systole is the contraction of a heart chamber; diastole is the relaxation of a chamber.

Outline the sequence of blood flow through the heart for a complete cycle starting with systemic venous return.

Systemic veins → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary trunk → lungs (gas exchange) → pulmonary veins → left atrium → mitral valve → left ventricle → aorta → systemic circulation; returns via systemic veins to the right atrium.

What is cardiac output and how is it calculated?

Cardiac output is the volume of blood discharged from a ventricle per minute; CO = heart rate × stroke volume.

What is stroke volume, and what factors determine its value?

Stroke volume is the amount of blood ejected by a ventricle per beat; determined by preload (EDV), contractility, and afterload.

What is preload and the Frank-Starling law of the heart?

Preload is the degree of stretch of ventricular muscle cells at end of diastole (EDV); greater preload leads to greater force of contraction (Frank-Starling law).

What is central venous pressure and why is it clinically important?

Pressure in the right atrium; affects flow into the heart and peripheral venous pressure; elevated CVP can indicate heart dysfunction and edema.

What is the baroreceptor reflex, and how does it regulate blood pressure?

Baroreceptors detect BP changes and influence the cardioinhibitory and cardioaccelerator reflexes via the medulla, adjusting heart rate and peripheral resistance to maintain BP.

Name common factors and outcomes associated with hypertension.

High arterial blood pressure; risk factors include obesity, high salt/sugar intake, stress; can lead to atherosclerosis, heart disease, stroke; managed by diet, exercise, and medications.

How are arteries structurally different from veins, and what are their primary functions?

Arteries have thick walls with three tunics (endothelium, smooth muscle, elastic tissue) to withstand and regulate high-pressure blood flow away from the heart; veins have thinner walls, less smooth muscle, and valves to return blood at lower pressure and serve as reservoirs.

What are precapillary sphincters and their role in capillary blood flow?

Smooth muscle bands that surround the entrance to capillaries and regulate blood flow into capillary beds.

What are the four main methods capillaries use to exchange substances with tissues, and what drives filtration vs. reabsorption?

Diffusion (gas and small solutes), filtration (hydrostatic pressure), osmosis/colloid osmotic pressure, and transcytosis; filtration predominates at the arteriolar end, reabsorption at the venular end, aided by osmotic pressure.

What is the hepatic portal system and its primary purpose?

A portal venous system where blood from abdominal viscera drains into the hepatic portal vein, goes to the liver for processing, then exits to the inferior vena cava via hepatic veins.

What is the Circle of Willis, and why is it important?

Cerebral arterial circle formed by the internal carotid arteries and basilar artery; provides redundant blood supply to the brain.

What are the major branches of the aortic arch?

Brachiocephalic trunk, left common carotid artery, and left subclavian artery.

How are the upper limb veins organized and how do they connect to larger veins?

Deep veins (digital to radial/ulnar to brachial to axillary) and superficial veins (basilic and cephalic) drain the upper limb and join larger veins (e.g., axillary, subclavian) that eventually feed into the superior vena cava.

Where are common arterial pulse points, and what is their clinical use?

Temporal, carotid, brachial, radial (and other sites); used to assess heart rate, rhythm, and pulse strength.

What are the main forces driving capillary exchange, and which side of the capillary dominates filtration vs. reabsorption?

Hydrostatic pressure drives filtration from arteriolar ends; colloid/osmotic pressure drives reabsorption at venular ends; diffusion and transcytosis aid substance exchange; lymphatics drain excess interstitial fluid.

What is the typical adult blood volume and its relation to body weight?

About 5 liters; roughly 8% of body weight.

What is the role of the coronary sinus?

Collects venous blood from the myocardium and drains into the right atrium.

What happens to blood flow during exercise with regard to capillary beds in different tissues?

Muscle capillaries receive more blood flow, while digestive system capillaries receive less; during meals, digestive capillaries receive more blood flow. Capillary distribution adapts to activity.