External Features of the Heart Flashcards
Measurements of the heart
12 x 9 cm
Weight = 300g in males and 250g in females
Relations of the heart
Anteriorly: Sternum
Posteriorly: Vertebral column
Inferiorly: Diaphragm
Laterally: Lung and pleura
What are the surfaces of the heart?
Anterior/sternocostal
Inferior/diaphragmatic
Left lateral
What are the borders of the heart?
Surfaces are demarcated by upper, inferior, right and left borders
What are the grooves/sulci of the heart?
Atrioventricular/coronary sulcus: Separates the atria from the ventricles
Interatrial groove: Groove between the atria and is faintly visible posteriorly, while anteriorly, it is hidden by the aorta and pulmonary trunk
Anterior interventricular groove: Nearer to the left margin of the heart
Posterior interventricular groove: Situated on the diaphragmatic or inferior surfaces fo the heart
What is the apex of the heart?
The apex is the lowest part of the heart which faces downwards, forward and left
Which structure forms the apex of the heart?
Formed entirely by the left ventricle
Location of the apex of the heart
Situated in the left fifth intercostal space (9 cm lateral to the midsternal line just medial to the midclavicular line)
Typically overlapped by the anterior border of the left lung
Pulsation of the heart can be felt over this region in living subjects
In children younger than 2 the apex is situated in the left side of the fourth intercostal space in the midclavicular line
Which structures form the base/posterior surface of the heart?
Formed mainly by the left atrium and by part of the right atrium
Relation of the base of the heart
Four pulmonary veins entering the left atrium
Superior and inferior vena cavae which open into the right atrium
Related to T5-T8 in the lying posture and descends by one vertebra in the erect posture
Which structures separate the base of the heart from the vertebral column?
Pericardium, the right pulmonary veins, the aorta and the esophagus
Which structures form the upper border?
Slightly oblique
Formed by the two atria (mainly the left atrium)
What structures form the right border?
Mostly vertical
Formed by the right atrium
Extends from superior vena cava to inferior vena cava
What structures form the inferior border?
Mostly horizontal
Mostly formed by the right ventrical and partly by the left ventrical near the apex
Extends from the IVC to the apex
What structures form the left border?
Oblique and curved
Formed mainly by the left ventrical and partly by the left auricle
Separates the anterior and left surfaces of the heart
Extends from the apex to the left auricle
What structures form the anterior surface of the heart?
Mainly right atrium and right ventricle
Partly left atrium and left ventricle
Most of the anterior surface is covered by the lungs but the part behind the cardiac notch is uncovered
Left atrium is mostly covered by the aorta and pulmonary trunk on the anterior surface
What structures form the inferior/diaphragmatic surface?
Left 2/3rds formed by left ventricle and right 1/3rd formed by right ventricle
The inferior surface of the heart is traversed by the posterior interventricular groove and is directly downwards and slightly backwards
It rests on the central tendon of the diaphragm
What structures form the left lateral surface of the heart?
Formed mostly by the left ventricle and partly by the left auricle
The upper part of the surface is crossed by the coronary sulcus
Related to the left phrenic nerve, left pericardiacophrenic vessels and pericardium
What is the crux of the heart?
Meeting point of interatrial (IA), atrioventricular (AV) and posterior interventricular (IV) grooves
