Heart Anatomy and Circulation - Flashcards

A comprehensive set of questions and answers covering heart anatomy, membranes, chambers, valves, coronary circulation, common disorders, and clinical considerations to study for exams.

Where is the human heart located within the body?

In the thoracic cavity, medially between the lungs in the mediastinum, within the pericardial cavity.

What is the pericardium and what are its two sublayers?

The pericardium is the double-walled sac around the heart; it has an outer fibrous pericardium and an inner serous pericardium.

What are the two layers of the serous pericardium and how are they related to the heart wall?

Parietal pericardium (fused to the fibrous pericardium) and visceral pericardium (epicardium; fused to the heart).

What cavity lies between the epicardium and the pericardium, and what does it contain?

The pericardial cavity, filled with lubricating serous fluid.

What are the three layers of the heart wall from outermost to innermost?

Epicardium (visceral pericardium), Myocardium, Endocardium.

Which layer of the heart wall is primarily responsible for pumping blood?

The myocardium, a thick layer of cardiac muscle.

Which ventricle is thicker and why?

The left ventricle is thicker because it must generate high pressure to pump blood through the systemic circuit.

What are the four chambers of the heart?

Right atrium, left atrium, right ventricle, left ventricle.

What are the two main circulatory paths in the heart called, and what do they do?

Pulmonary circuit (to and from the lungs for gas exchange) and systemic circuit (to the rest of the body).

Where do the coronary arteries originate, and what are the key aortic sinuses involved?

They originate from the aorta just above the aortic semilunar valve; the left coronary artery comes from the left posterior aortic sinus and the right coronary from the anterior aortic sinus.

Which vessels carry deoxygenated blood in the pulmonary circuit, and which carry oxygenated blood back to the heart?

Pulmonary trunk/arteries carry deoxygenated blood to the lungs; pulmonary veins carry oxygenated blood back to the left atrium.

What vessel drains most of the heart’s venous blood into the right atrium?

The coronary sinus.

What is the function of the chordae tendineae and papillary muscles?

They anchor the atrioventricular valve leaflets and tense them during ventricular contraction to prevent backflow (regurgitation).

What is the moderator band and where is it located?

A band of muscle in the right ventricle that reinforces the ventricle wall and aids conduction.

How many papillary muscles are in the left ventricle and what are they called?

Two papillary muscles: the anterior and posterior.

What is the fossa ovalis and what does it signify?

A shallow depression in the interatrial septum; it marks the former site of the foramen ovale in fetal life.

What are the atrioventricular and semilunar valves called, and where are they located?

Atrioventricular valves (tricuspid on the right, mitral on the left) between atria and ventricles; semilunar valves (pulmonary and aortic) at the exits of the ventricles.

Which valves have chordae tendineae and papillary muscles, and which do not?

Atrioventricular valves have chordae tendineae and papillary muscles; semilunar valves do not.

Describe the structure and function of the endocardium.

Endocardium lines the chambers and covers valves; it's made of endothelium and helps regulate contractility and ionic balance.

What is the epicardium, and how is it related to the pericardium?

The epicardium is the visceral layer of serous pericardium; it is the outer layer of the heart wall.

What are pectinate muscles and where are they found?

Ridges of muscle found mainly in the right atrium and the right atrial auricle; more prominent there.

What is the atrial appendage (auricle) and why is it relevant?

An ear-like extension of each atrium that can fill with blood; it contributes to atrial volume.

What is the interatrial septum and the interventricular septum?

Interatrial septum divides the atria; interventricular septum divides the ventricles.

What is the atrioventricular septum?

The septum between the atria and ventricles containing the openings for the AV valves.

What is the cardiac skeleton and its function?

Dense connective tissue rings around the valve openings; provides attachment for valves and an electrical boundary.

Explain the flow of blood through the heart starting from the right atrium.

Right atrium → right ventricle through tricuspid valve → pulmonary trunk → lungs (gas exchange) → pulmonary veins → left atrium → left ventricle through mitral valve → aorta → systemic circulation.

What are the two main coronary arteries and what areas do they supply?

Left coronary artery supplies the left heart and interventricular septum (LAD and circumflex branches); right coronary artery supplies the right atrium, portions of both ventricles, and the conduction system.

What is an anastomosis in the heart?

A network where vessels interconnect to provide alternate routes for blood flow in case of blockage.

What is myocardial infarction (MI) and how is it detected?

MI is heart muscle death due to ischemia; detected by ECG changes (ST, Q waves) and elevated cardiac enzymes like CK-MB and troponin.

What is the condition Tetralogy of Fallot and its four components?

A congenital defect with four features: pulmonary infundibular stenosis, overriding aorta, ventricular septal defect, and right ventricular hypertrophy (blue baby when severe).

What is patent foramen ovale and how common is it?

A condition where the foramen ovale fails to close after birth; can be benign or require surgery in rare cases; present in about 20–25% of people.

What is cardiac tamponade and what can cause it?

Excess fluid in the pericardial cavity compressing the heart and reducing filling; causes include trauma, inflammation, or disease.

What is the difference between stenosis, insufficiency, and prolapse in heart valves?

Stenosis is valve stiffening narrowing; insufficiency is incomplete closure causing regurgitation; prolapse is valve cusp displacement leading to leakage.

What is the term for listening to heart sounds and why is it useful?

Auscultation; it helps detect murmurs and valvular or septal abnormalities.

What role does endothelin play in the heart and vessels?

Endothelins are potent vasoconstrictors produced by endothelium that help regulate vascular tone and contractility.

Why is CPR important and what are the current standards for chest compressions?

CPR maintains circulation when the heart stops; perform compressions at least 5 cm deep at about 100 per minute, focusing on chest compressions rather than rescue breaths.