Pericardium, Heart and Innervation Flashcards
What are the two main layers of the pericardium?
The fibrous pericardium and serous pericardium.
What are the two layers of the serous pericardium?
The parietal layer and visceral layer (epicardium).
What is the function of the pericardium?
It encloses and protects the heart, prevents excessive dilation, and reduces friction.
What structures form the fibrous pericardium?
Dense connective tissue attached to the diaphragm and great vessels.
What is the clinical significance of the pericardial cavity?
It contains serous fluid, reducing friction between the pericardial layers.
What is cardiac tamponade?
A life-threatening condition where fluid accumulation in the pericardial cavity compresses the heart.
What is the arterial supply of the pericardium?
The pericardiacophrenic, musculophrenic, and coronary arteries.
What veins drain the pericardium?
The pericardiacophrenic veins, draining into the brachiocephalic veins.
What nerves supply the pericardium?
The phrenic nerve (somatic sensation), vagus nerve, and sympathetic trunk.
What is the location of the heart in the thoracic cavity?
In the middle mediastinum, posterior to the sternum, between the lungs.
What are the borders of the heart?
Right border (right atrium), left border (left ventricle and auricle), inferior border (right ventricle), superior border (atria and great vessels).
What are the surfaces of the heart?
Anterior (sternocostal), inferior (diaphragmatic), and posterior (base).
What are the chambers of the heart?
Right atrium, right ventricle, left atrium, left ventricle.
What structure separates the right and left atria?
The interatrial septum.
What structure separates the right and left ventricles?
The interventricular septum.
What is the function of the right atrium?
It receives deoxygenated blood from the body and pumps it into the right ventricle.
What is the function of the left atrium?
It receives oxygenated blood from the lungs and pumps it into the left ventricle.
What is the function of the right ventricle?
It pumps deoxygenated blood into the pulmonary circulation via the pulmonary trunk.
What is the function of the left ventricle?
It pumps oxygenated blood into the systemic circulation via the aorta.
What are the main heart valves?
The tricuspid, pulmonary, mitral, and aortic valves.
What is the function of the tricuspid valve?
It prevents backflow of blood from the right ventricle into the right atrium.
What is the function of the pulmonary valve?
It prevents backflow from the pulmonary trunk into the right ventricle.
What is the function of the mitral valve?
It prevents backflow from the left ventricle into the left atrium.
What is the function of the aortic valve?
It prevents backflow from the aorta into the left ventricle.
What structures anchor the atrioventricular valves?
Chordae tendineae and papillary muscles.
What is the fibrous skeleton of the heart?
A dense connective tissue framework that supports the heart valves and anchors the myocardium.
What are the main coronary arteries?
The right and left coronary arteries.
What areas of the heart does the right coronary artery supply?
The right atrium, right ventricle, SA node, AV node, and part of the left ventricle.
What areas of the heart does the left coronary artery supply?
The left atrium, left ventricle, and most of the interventricular septum.
What are the main cardiac veins?
The great cardiac vein, middle cardiac vein, small cardiac vein, and coronary sinus.
What is the function of the coronary sinus?
It collects venous blood from the heart and drains into the right atrium.
What is the conducting system of the heart?
The SA node, AV node, AV bundle, right and left bundle branches, and Purkinje fibers.
What is the function of the sinoatrial (SA) node?
It acts as the pacemaker, initiating the heartbeat.
What is the function of the atrioventricular (AV) node?
It delays electrical impulses to allow atrial contraction before ventricular contraction.
What is the function of the atrioventricular bundle (Bundle of His)?
It transmits impulses from the AV node to the ventricles.
What is the function of the Purkinje fibers?
They distribute impulses rapidly to the ventricular myocardium, ensuring synchronized contraction.
What is the autonomic innervation of the heart?
The heart is innervated by the cardiac plexus, receiving sympathetic and parasympathetic fibers.
What is the effect of sympathetic stimulation on the heart?
Sympathetic stimulation increases heart rate and force of contraction.
What is the effect of parasympathetic stimulation on the heart?
Parasympathetic stimulation decreases heart rate and force of contraction.
What is the clinical significance of the cardiac plexus?
It coordinates autonomic control of heart rate and force of contraction.
What are the major branches of the right coronary artery?
The sinoatrial nodal artery, right marginal artery, posterior interventricular artery.
What are the major branches of the left coronary artery?
The anterior interventricular artery (LAD) and circumflex artery.
What is the anatomical basis of referred cardiac pain?
Cardiac pain is referred to the left arm, shoulder, neck, and jaw due to shared spinal segments (T1-T4).
What is the blood supply of the interventricular septum?
The anterior two-thirds is supplied by the LAD, and the posterior one-third by the posterior interventricular artery.
What are the three layers of the heart wall?
Endocardium, myocardium, and epicardium.
What is the role of the endocardium?
It lines the heart chambers and valves, providing a smooth surface for blood flow.
What is the role of the myocardium?
It contains cardiac muscle, responsible for contraction and blood ejection.
What is the role of the epicardium?
It is the outermost layer, consisting of visceral pericardium and fat.
What is the embryological origin of the heart?
The heart develops from the mesodermal cardiogenic plate.
What is the clinical significance of the transverse pericardial sinus?
It allows surgical clamping of the aorta and pulmonary trunk during procedures like cardiopulmonary bypass.
