Gross Anatomy of the Heart Flashcards
Location of the heart
- Located in the middle mediastinum between the lungs within the thoracic cavity.
- Located anterior; deep to the sternum and costal cartilages 3-5.
- The apex is near the midclavicular line (MCL) at teh level of the 5th intercostal space.
Mediastinum
A space located between the two pleural cavities and contains all the thoracic viscera except the lungs. It runs from the superior thoracic aperture to the diaphragm and from the sternum to the thoracic vertebral bodies.
Layers of the pericardium
- Fibrous pericardium
- Parietal layer of serous pericardium
- Visceral layer of serous pericardium
Fibrous pericardium
Dense CT, fused to the diaphragm and tunica adventitia of the great vessels (aorta, SVC). The fibrous pericardium and heart move with the diaphragm during respiration.
Parietal layer of serous pericardium
Simple squamous epithelium and thin layer of LCT lines the inner surface of fibrous pericardium. It is reflected back onto the heart where the great vessels enter and leave the heart to become the visceral layer of serous pericardium (=epicardium).
Visceral layer of serous pericardium
Epicardium.
This is the outermost layer of the three layers of the heart, with the two other layers being the myocardium and endocardium.
Adipose tissue frequently deposits between the epicardium and mycoardium, making identification and dissection of the coronary vessels difficult.
Pericardial cavity
Is located between the parietal and visceral layers, it is a potential space with thin film of serous fluid = reduces friction as the heart pumps.
Transverse pericardial sinus
Lies anterior to the SVC and posterior to the ascending aorta and pulmonary trunk.
Oblique sinus
Lies posterior to the heart in the pericardial sac.
What vessels open into the right atrium?
SVC, IVC and coronary sinus.
Fossa ovalis
A remnant of the foramen ovale in the interartrial septum.
Describe the anatomy of the walls of the right atrium.
The internal atrial wall is smooth posteriorly and rough (pectinate muscles) anteriorly.
What is the junction between the smooth wall and pectinate muscles called in the right atrium?
Sulcus terminal exteriorly and crista terminalis internally.
What is the term for the muscle ridges in the right ventricle?
Trabeculae carnae
What separates the inflow tract from the outflow tract in the right ventricle?
The supraventricular crest which is an elevated smooth musclar ridge.
Conus arteriosus
The superior narrowing of the outflow track. Also termed infudibulum.
Septomarginal trabecula
Also called the ‘moderator band’.
Curved muscle bundle travelling from the inferior interventricular septum to the base of the anterior papillary muscle in the right ventricle.
It carries part of the conducting system.
Describe the structure of the walls of the left atrium.
Mostly smooth walled except the small left auricle which has pectinate muscles.
Difference between right and left ventricle.
The left ventricle has a thicken wall, and the trabeculae carnae are finer and more numerous than RV. Has large papillary muscles.
Aortic vestibule
Outflow area of LV.
Custs of pulmonary valve
Anterior, right and left.
Cusps of aortic valves
Posterior, right and left.
Tricuspid valve cusps
septal, anterior and posterior.
Mitral valve cusps
Anterior, posterior.