Anatomy of the heart Flashcards
What are the external features of the heart?
- Conical in shape
- Apex (formed by the left ventricle)
- Base (Formed by the atrium of the heart “mainly in the posterior surface)
- Four borders: (1. Upper, 2. Lower, 3. Right, 4. Left)
- Four surfaces: (Sternocostal, diaphragmatic, left and right surfaces)
Describe the Apex of the heart
- Downwards, forwards, and to the left
- Formed by the left ventricle mainly
- Lies opposite to the left 5th intercostal space, 3.5 inches from the median plane (medial to the mid-clavicular line)
- Overlapped by the left pleura and the lung
Where is the location of the apex of the heart?
The left 5th intercostal space, 3.5 inches from the median plane (just below the left nipple)
Describe the base of the heart
- Backwards and to the left
- Formed by the left atrium mainly (RA to a small extent)
- Opposite to the middle four thoracic vertebrae (T5-8)
- Related posteriorly to the right pulmonary veins, Esophagus and the descending aorta
What structures overlap the apex of the heart?
Left pleura and the lung
Which vertebral segments are correlated with the base of the heart?
T5-T8
What separates the base of the heart from the inferior surface?
The coronary sinus
What are the borders of the heart?
1) Upper border:
- Formed by the two atria (mainly the left)
2) Right border:
- Formed by the right atrium (extends from the opening of the superior vena cava to the opening of the inferior vena cava)
3) Left border:
- Formed mainly by the left ventricle and partly by the left auricle
4) Lower border:
- Formed mainly by the right ventricle, slightly concaved downwards due to the upward convexity of the diaphragm
What are the structures that overlap the upper border of the heart?
1) Pulmonary trunk
2) Ascending aorta
3) Superior vena cava
What are the surfaces of the heart?
1) Sternocostal surface
2) Diaphragmatic surface
3) Left surface
4) Right surface
Describe the sternocostal surface of the heart
- Divided by the coronary groove
- Its atrial portion lies above the coronary groove and is made up of the right atrium and the auricle of the left atrium
- Its ventricular portion lies below the coronary groove, and it is formed 1/3 by the left ventricle and 2/3 by the right ventricle separated by the anterior interventricular groove (which contains the left anterior descending artery “anterior interventricular artery” and the great cardiac vein)
- When a tab wound behind the sternum at the fourth intercostal space it is probably hitting this surface
Describe the diaphragmatic surface of the heart
- Directed downwards & slightly backward
- Formed by the two ventricles (Left ventricle mainly)
- The posterior interventricular groove divides it into right and left ventricles
Which structures are related to the diaphragmatic surface?
1) Central tendon and the left cupola of the diaphragm
Describe the left surface of the heart
- Formed by the left ventricle mainly + THE LEFT ATRIUM AURICLE
Which structures are related to the left surface of the heart?
1) Pericardium
2) Left phrenic nerve
3) Left pericardiacophrenic vessels
Describe the right surface of the heart
Formed by the right atrium
Which structures are related to the right surface of the heart?
1) Pericardium
2) Right phrenic nerve
3) Right pericardiophrenic vessels
What are the grooves of the heart?
1) Atrioventricular groove (coronary groove)
2) Interatrial groove
3) Posterior interventricular groove (“on the diaphragmatic surface” Contains the posterior interventricular artery, and the middle cardiac vein)
4) Anterior interventricular groove (“lies on the sternocostal surface”, has the anterior interventricular artery “left anterior descending artery”, and the great cardiac vein)
Describe the coverings of the heart
1) Fibrous Pericardium (Its base fuses with the central tendon of the diaphragm)
2) Serous pericardium (enclosed by the fibrous pericardium, consists of a parietal layer “firmly adherent to the fibrous epicardium” and a visceral layer “covers the heart and is adherent to it)
3) Pericardial cavity (space between the parietal and visceral layers, containing a thin fil of fluid which enables the heart to beat frictionless)
Which ligament attaches the fibrous pericardium to the sternum?
The sternopericardial ligament
What is the function of the fibrous pericardium?
It prevents the heart from overfilling
What type of cells is the serous pericardium made of?
- Simple squamous epithelium
- It directly reflects on the roots of the great vessels
What happens in pericarditis?
It is when inflammation occurs at the serous cavity of the epicardium making a detectable sound on auscultation
What is pericardial effusion?
It is the accumulation of fluid within the pericardial sac
