Anterior Interventricular Artery Landmark

• The cardiovascular system consists of the heart and vessels.

The Heart

• The heart is a hollow muscular organ
• The heart sits in the middle of the thoracic cavity
• The heart wall is primarily composed of cardiac muscles
• The heart comprises four chambers: two atria (right and left) and two ventricles (right and left)
• The septum separating the two atria is called the interatrial septum
• The two ventricles are separated by the interventricular septum

Heart Surfaces

• The heart features an apex, base, sternocostal surface, and diaphragmatic surface

The Apex

• The left ventricle forms the apex of the heart
• The apex is opposite the left fifth intercostal space, approximately 3 1/2 inches from the midline

The Base

• The base is mainly formed by the left atrium and a small portion of the right atrium

Sternocostal Surface

• The sternocostal surface includes both atrial and ventricular parts
• The atrial part is mainly the right atrium and left auricle
• The ventricular part includes the right ventricle (2/3) and left ventricle (1/3)

Grooves on the Sternocostal Surface

• Atrio-ventricular groove (coronary sulcus) separates the atria from ventricles, and houses the coronary arteries
• Anterior interventricular groove separates the right from the left ventricle, and contains the anterior interventricular artery and great cardiac vein

Diaphragmatic Surface

• The diaphragmatic surface consists of the left ventricle (2/3) and right ventricle (1/3)
• The posterior interventricular groove separates the two ventricles, containing the posterior interventricular artery and middle cardiac vein

Borders of the Heart

• The right border is formed by the right atrium
• The lower border is formed by the right ventricle, except at the apex where it is formed by the left ventricle
• The left border is formed by the left ventricle and left auricle
• The upper border is formed by both atria, mainly the left

Heart Valves

• Atrioventricular Valves include:
  • Tricuspid Valve: located between the right atrium and the right ventricle
  • Mitral Valve: located between the left atrium and the left ventricle
• Semilunar Valves feature pocket-like cusps with a concave upper surface
  • Pulmonary Valve
  • Aortic Valve

Arterial Supply of the Heart

• The cardiac muscle gets is supplied by the coronary arteries
• There are two coronary arteries: right and left
• Both arise from the ascending aorta, above the aortic valve

Venous Drainage of the Heart

• Coronary Sinus drains into the right atrium
• The veins that drain into the coronary sinus include:
  • Great Cardiac Vein: in the anterior interventricular groove
  • Middle Cardiac Vein: in the posterior interventricular groove
  • Small Cardiac Vein: runs along the lower border of the heart
  • Oblique vein of the left atrium.
  • Posterior vein of the left ventricle.
• Anterior Cardiac Veins: one or two veins drain the anterior wall of the right ventricle and open directly into the right atrium.

Pericardium

• The pericardium is a fibro-serous sac enclosing the heart, composed of:
  • Outer Fibrous Pericardium
  • Inner Serous Pericardium

Blood Circulation

• The right atrium receives deoxygenated blood from the head, neck and rest of body via the superior and inferior vena cava, respectively
• Blood passes from the right atrium to the right ventricle through the tricuspid valve
• The right ventricle pumps blood to the pulmonary trunk, and then to the lungs for oxygenation
• Oxygenated blood returns to the left atrium via the 4 pulmonary veins
• Oxygenated blood passes from the left atrium to the left ventricle through the mitral valve
• The left ventricle contracts to pump blood into the aorta

Types of Blood Circulation

• Systemic circulation
• Pulmonary circulation
• Portal circulation

Systemic Circulation

• The left ventricle contracts, pushing oxygenated blood through the aorta; deoxygenated blood is then collected by veins to reach the right atrium

Pulmonary Circulation

• The right ventricle contracts, pushing deoxygenated blood to the lungs through the pulmonary trunk for oxygenation, and then blood returns to the left atrium through 4 pulmonary veins

Portal Circulation

• Involves the circulation of blood between two sets of capillaries
• Transports digestive materials from the gastric tube to the liver

Vascular System

• Includes three types of vessels:
  • Arteries
  • Veins
  • Capillaries

Aorta

• Originates from the left ventricle

Pulmonary Trunk

• Extends from the right ventricle to the lungs

Vena Cava

• Superior vena cava opens to the right atrium
• Inferior vena cava opens to the right atrium

The anterior interventricular artery, also known as the left anterior descending artery, is located in the anterior interventricular sulcus. Surgeons use this sulcus as a primary anatomical landmark to find the artery during cardiac procedures.