CH 19: Heart

What is the orientation of the heart in the thorax?

The heart is slightly to the left, with the apex pointing downward and leftward.

Where is the heart located in the thorax?

The heart is located in the mediastinum between the lungs, behind the sternum.

At what level is the base of the heart broad?

The base of the heart is broad at the 2nd intercostal space.

Where is the apex of the heart located?

The apex is located between the 5th and 6th rib.

What are the layers of the pericardium?

The pericardium consists of a tough outer fibrous layer and a serous layer with parietal and visceral (epicardium) components.

What is found in the pericardial cavity?

The pericardial cavity contains serous fluid.

What are the three layers of the heart wall?

The three layers of the heart wall are the epicardium, myocardium, and endocardium.

Which chamber of the heart receives deoxygenated blood?

The right atrium receives deoxygenated blood from the superior/inferior vena cava and coronary sinus.

What is the function of the right ventricle?

The right ventricle pumps blood into the lungs via the pulmonary trunk.

What does the left atrium receive?

The left atrium receives oxygenated blood from the pulmonary veins.

Where is the thickest wall of the heart and what is its purpose?

The left ventricle has the thickest walls to pump oxygenated blood to the body via the aorta.

Name the atrioventricular valves.

The atrioventricular valves are the tricuspid valve (between right atrium and ventricle) and the bicuspid (mitral) valve (between left atrium and ventricle).

Where are the semilunar valves located?

The semilunar valves are the pulmonary valve (between right ventricle and pulmonary trunk) and the aortic valve (between left ventricle and aorta).

How does a drop of blood flow through the heart?

Deoxygenated blood flows from the right atrium through the tricuspid valve to the right ventricle, then through the pulmonary valve to the lungs, and oxygenated blood returns from the lungs via pulmonary veins to the left atrium, through the mitral valve to the left ventricle, and out through the aortic valve to the body.

What are the structural features of cardiac muscle tissue?

Cardiac muscle tissue is short, branching, can have one or two nuclei, and is rich in mitochondria for endurance.

What are intercalated discs and their importance in cardiac muscle?

Intercalated discs are complex cellular junctions that include fasciae adherens (desmosomes) for cell adhesion during contraction and gap junctions that allow for the passage of ions and faster signal transmission.

What is the function of the sinoatrial node?

The sinoatrial node is the pacemaker of the heart that initiates the heartbeat.

What is the role of the atrioventricular node?

The atrioventricular node delays the electrical signal to allow time for ventricular filling.

Describe the path of the conduction system in the heart.

The conduction pathway includes the sinoatrial node, atrioventricular node, Bundle of His, and Purkinje fibers.

Where do the coronary arteries originate?

The right and left coronary arteries originate from the aorta to supply oxygenated blood to the heart.

What do cardiac veins do?

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

Define coronary artery disease.

Coronary artery disease is the buildup of fatty plaque (atherosclerosis) in the coronary arteries, potentially leading to angina or heart attack.

What is heart failure?

Heart failure is a condition where the heart is too weak to pump blood effectively.

What is atrial fibrillation?

Atrial fibrillation is characterized by rapid and irregular heartbeat, reducing blood flow efficiency.

What is ventricular fibrillation?

Ventricular fibrillation is rapid and uncoordinated beating of the heart, which prevents effective blood pumping.