L-10 external features of the Heart Flashcards
Where is the position of the heart
Present in the mediastinum
What is the mediastinum
Space between the lungs which also contains the major blood vessels, esophagus ,nerves and trachea
What are the external features of the heart
▪️Pyramidal, hollow, four chambered muscular organ
▪️Apex, a base and two surfaces
How is the base placed and where is the Apex directed
Base is placed posteriorly and Apex should be directed forwards downwards to the left
Name the surfaces of the heart
Sternocostal (anterior) posterior surface (base) diaphragmatic surface (inferior)
Describe the sternocostal surface of the heart
▪️Formed by the four chambers right atrium,left auricle and mainly right ventricle
▪️Related to the sternum and costal cartilage and anterior Borders of both lungs and pleura
What is an auricle
Anterior part of each Atrium is a wrinkled flag like extension called an auricle
What are the grooves found in the sternocostal surface of the heart
▪️Atrioventricular groove (coronary sulcus) which separates the atria from the ventricles
Coronary arteries lie in the groove
▪️Anterior interventricular groove separates the right from the left ventricle it contains the anterior interventricular artery and the great cardiac vein
Describe the posterior surface of the heart
▪️Formed by the back of both the left and the right atria mainly the left
▪️Lies opposite the middle four (5 to 8)Thoracic vertebrae
▪️The four pulmonary veins enter the left atrium and the superior and inferior vena cava entering the right atrium
Where can the coronary sinus be seen
Between the back of the left atrium and the back of the left ventricle
Describe the diaphragmatic surface
▪️Triangular in shape and rests on the diaphragm
▪️it is formed by both the ventricles mainly the left
What groove does the diaphragmatic surface contain
Posterior interventricular groove which contains the posterior interventricular artery in the middle cardiac vein
What are the borders of the heart
▪️The right border is formed by the right atrium
▪️The left border is formed by the left ventricle
▪️The upper border is formed by both atria mainly the left
▪️The lower border is formed by the right ventricle and the apex of the left ventricle
How is the upper border hidden
By the ascending aorta and the pulmonary trunk
Describe the borders of the heart in relation to the surface anatomy
Point 1: lower border of the left second coastal cartilage 1.5 inches from the middle line
Point 2:upper border of the right third coastal cartilage 1 inch from the middle line
Point 3: right sixth coastal cartilage half an inch from the middle line
Point 4: left fifth intercostal space 3.5 inches from the middle line
Describe the surface anatomy of the valves
(PAMT 3cc 3is 4cc 4is)
1-pulmonary valve: behind the left border of the sternum opposite the 3rd costal cartilage
2-aortic valve:behind the left border of the sternum opposite the 3rd intercostal space
3-mitral valve:behind the left border of the sternum opposite the 4th costal cartilage
4-tricuspid valve: mid line opposite the 4th intercostal space
What would the marking of the heart be affected by
Posture
breathing
hypertrophy
dilation of the ventricle
What is the pericardium and describe it
▪️The heart and its pericardium make up the contents of the Mediastinum
Left and right phrenic nerves lie to the of left and right of the pericardium respectively
▪️Formed of two parts:
Outer fibrous pericardium and inner serous pericardium
Describe the outer fibrous pericardium
Conical in shape
Tough sac enclosing the heart and provides attachments to the adjacent structures
▪️Anteriorly it is attached to the sternum
▪️Posteriorly it’s related to the descending aorta and esophagus
Describe the inner serous pericardium
Formed of two layers which are continuous with each other
Outer parietal layer lines the fibrous pericardium
Innervision there covers the heart the continuance between the 2 layers takes place at points where the major blood vessels enter and leave the heart
 what are the parts of serous pericardium
Between the two layers is the pericardial
cavity which is a potential space that contains a small amount of fluid which facilitates the movement of the heart
