Structure of Heart
Both right and left sides of the heart pump equal amounts of blood
Describe the general location, size, and shape of the heart.
Location: mediastinum- anatomical region extending from sternum to the vertebral column, the first rib and between the lungs
Size: size of a closed fist
Shape: upside down pear
What is the epicardium synonymous with?
Visceral pericardium
Describe the left coronary artery
Supplies blood to the left side of the heart muscle (L. Ventricle & L. Atrium)
-Branches off the Aortic Sinus on the left side of the heart
-Gives rise to:
1. Anterior Interventricular branch of the Left Coronary Artery
2. Circumflex branch of the Left Coronary Artery
Define Angina
A sense of heaviness or pain in the chest resulting from temporary and reversible ischemia.
Describe the layers of the heart wall.
Epicardium: visceral layer of serous pericardium
Myocardium: cardiac muscle, pumps
Endocardium: smooth lining, minimizes friction
Describe the systemic and pulmonary circuits
Systemic circuit: Takes oxygenated blood from left side of heart to deliver oxygen to tissues
-Delivers blood to right side of heart
Pulmonary circuit: Takes deoxygenated blood from right side of heart to pick up oxygen from lungs
-Delivers blood to left side of heart
Name all layers of the heart's pericardial sac from superficial to deep
-Fibrous pericardium
-parietal layer of serous pericardium
-visceral layer of serous pericardium (aka epicardium)
Describe the right coronary artery
Supplies the right atrium and sinuatrial node (pacemaker)
-Branches of the Aortic Sinus on the right side of the heart
-Gives rise to:
1. Posterior Interventricular branch of the Right Coronary Artery
2. Marginal branch of the Right Coronary Artery
Define Ischemia
The deficiency of blood flow to the cardiac muscle.
What is systemic or pulmonary edema?
Unequal pumping of blood between right and left sides of the heart
Identify where blood is oxygen-rich and where it's oxygen-poor.
Oxygen-rich: all areas of blood flow after lungs:
-left pulmonary veins, left atrium, left AV valve, aortic valve, aorta
Oxygen-poor: All areas of blood flow from the inferior venae cavae to the lungs:
Right atrium, Right AV valve, pulmonary valve, pulmonary trunk, pulmonary arteries
Describe the pericardial sac that encloses the heart and its different parts
Fibrous:
-superficial
-prevents over stretching of the heart, provides protection, and anchors the heart in mediastinum
Serous:
-deep double layer
-outer parietal layer and inner visceral (epicardium) layer
-contains serous fluid which prevents friction
Describe the great cardiac vein
Runs alongside the anterior interventricular artery
-Collects blood from the anterior aspect of the heart and carries it from the apex towards the coronary sulcus, then turns and empties into the coronary sinus
Define Myocardial Infarction
heart attack, the death of heart tissue
What are the four chambers of the heart?
Superior chambers: right and left atria
Inferior chambers: right and left ventricles
What do arteries, capillaries, and veins do?
Arteries: carry blood away from the heart
Capillaries: site of exchange
Veins: carry blood to the heart
What is the function of pericardial fluid
Lubricates the membranes and allows the heart to beat with minimal friction
Describe the coronary sinus
a large transverse vein in the coronary sulcus on the posterior side of the heart. it collects blood from veins and empties blood into the right atrium.
Describe bypass surgery
The replacement of diseased valves (often with
Trace the pathway of blood through the heart- starting with the Right Atrium
R Atrium--> thru R AV valve --> R Ventricle --> thru pulmonary valve --> pulmonary trunk & arteries --> lungs (pulmonary circulation) --> pulmonary veins --> L Atrium --> thru L AV valve --> L Ventricle -->Aortic Valve --> Aorta --> Body (systemic circulation) --> systemic veins --> vena cavae
Identify the surface features of the heart and correlate them with its internal four-chambered anatomy.
•Atrioventricular sulcus—separates atria and ventricles
•Interventricular sulcus—overlies the interventricular septum that divides the right ventricle from the left
•Sulci contain coronary arteries
•Interatrial septum-Wall that separates atria
•Pectinate muscles-Internal ridges of myocardium in right atrium and both auricles
•Interventricular septum-Muscular wall that separates ventricles
•Trabeculae carneae-Internal ridges in both ventricles-May prevent ventricle walls from sticking together after contraction
What is the significance of the endocardium?
Endocardium: simple squamous epithelium overlying a thin layer of areolar tissue
--> Covers the valve surfaces and is continuous with the endothelium of the blood vessels.
Compare and contrast the structure and function of the atrioventricular and semilunar valves.
Atrioventricular: regulate the openings between the atria and ventricles
--Right AV valve has three cusps
--Left AV valve has two cusps
Semilunar: regulate the blood flow from the ventricles into the great arteries.
--Both the pulmonary and aortic valves have 3 cusps shaped like shirt pockets
What are chordae tendineae and what is their function? What heart valve disorder results if the chordae tendineae fail to function properly?
Chordae tendineae: in the left ventricle- stringy cords connecting the heart valve cusps to the papillary muscles on the floor of the ventricle.
Function: prevent the AV valves from flipping inside out or bulging into the atria when the ventricles contract.
Improper functioning leads to:
Mitral Valve Prolapse- when one or both mitral valve cusps bulge into the atrium during ventricular contraction.