Heart Anatomy PDF

# External Features of the Heart ## Anatomical Site - The heart lies in the middle mediastinum (between both lungs), with slight deviation of its apex to the left. ## Parts of the Heart - The heart is formed of four chambers: - 2 atria - 2 ventricles - Both atria and ventricles are sepa...

# External Features of the Heart ## Anatomical Site - The heart lies in the middle mediastinum (between both lungs), with slight deviation of its apex to the left. ## Parts of the Heart - The heart is formed of four chambers: - 2 atria - 2 ventricles - Both atria and ventricles are separated from each other on the outer surface of the heart by a circular grove called artioventricular grove (coronary sulcus). ## Atria - Each atrium has a triangular outgrowth called auricle. - The 2 atria are separated from each other from inside by interatrial septum. ## Ventricles - The 2 ventricles are separated from each other from inside by the interventricular septum. - And from outside by the **anterior** and **posterior** interventricular grooves. # How Blood Circulates Inside the Heart? - Deoxygenated blood → superior vena cava and inferior vena cava → right atrium → tricuspid valve → right ventricle → pulmonary trunk → corresponding lungs → oxygenated blood → left atrium → mitral valve → left ventricle → ­­­­4 pulmonary valve → aorta → distributed to all the body. - The wall of the left ventricle is more thicker than the right ventricle. ## Interatrial septum ## Interventricular septum # Apex and Base - **Horizontal plane:** بالنسبة للى - **Vertical plane:** بالنسبة للى ## Surfaces of the Heart ### Sterno-costal Surface - Lies behind the sternum and costal cartilage. - Formed of 4 chambers: - Right ventricle (2/3). - Left ventricle (1/3). - Right atrium (mainly). - Left atrium (small part). ### Diaphragmatic Surface - Lies on the diaphragm. - Formed of: - Left ventricle (2/3). - Right ventricle (1/3). ## Borders of the Heart ### Superior Border - Formed by both artia (mainly the left). ### Right Border - Formed by the right atrium. ### Left Border - Formed mainly by the left ventricle and its upper part is formed by the left auricle. ### Inferior Border - Formed by both ventricles (mainly the right). # Grooves of the Heart ## 1- Atrio-ventricular Groove (Coronary Sulcus) - Site: between the 2 artia and 2 ventricles (circular groove). - Contents: - The main trunks of the right and left coronary arteries. - Circumflex branch of the left coronary artery. - Coronary sinus. ## 2- Anterior Inter-ventricular Groove - Site: between the 2 ventricles on the sternocostal surface. - Contents: - Anterior interventricular artery. - Great cardiac vein. ## 3- Posterior Inter-ventricular Groove - Site: between the 2 ventricles on the inferior surface. - Contents: - Posterior interventricular artery. - Middle cardiac vein. ## 4- Sulcus Terminalis - Faint groove (باهت) - Presents on the outer surface of the right atrium between the SVC and IVC. - Represented on the inner surface by the crista terminalis. # Surface Anatomy of the Heart ## Step one: (mesures on the horizontal plane). - First point: 0.5 inch from the midline - Second point: 1 inch from the midline - Third point: 1.5 inches from the midline - Fourth point: 3.5 inches from the midline ## Step two: (mesures on the vertical plane). - First point: at the right sixth costal cartilage. - Second point: at the right third costal cartilage. - Third point: at the left second costal cartilage. - Fourth point: at the left fifth intercostal space. ## Step three: (merge the two sets of numbers). - First point: 0.5 inch from the midline at the right sixth costal cartilage. - Second point: 1.0 inch from the midline at the right third costal cartilage. - Third point: 1.5 inches from the midline at the left second costal cartilage. - Fourth Point: 3.5 inches from the midline at the left fifth intercostal space. ## Step four: (values of the heart). - 3 = third rib - P = Pulmonary valve - 3.5 = third intercostal space - A = Aortic valve. - 4 = Fourth rib - M = Mitral value - 4.5 = fourth intercostal space - T = Tricuspid valve on the midline - Pulmonary valve lies behind the left border of the sternum opposite the 3rd costal cartilage. - Aortic valve lies behind the left border of the sternum opposite the 3rd intercostal space. - Mitral valve lies behind the left border of the sternum opposite the 4th costal cartilage. - Tricusped value lies at the midline opposite the 4th intercostal space. -The coronary sukus corresponds to a line between the first and the third points.