Exercise 20 Gross Anatomy of the Heart BI 232

The heart  Two-sided, double- pumping organ.  The left side controls the flow of blood to all tissues and cells in the body, where oxygen and nutrients are delivered and wastes are taken away.  The right side sends blood to the lungs, where oxygen stored in RBCs is replenished and CO2 is released

The Pericardium  Membranous sac  2 parts: outer fibrous pericardium that is fused to adjacent structures and an inner serous pericardium which is a delicate serous membrane that forms a double-layered sac around the heart.  The serous pericardium consists of parietal and visceral layers.

Mediastinum  The heart and pericardial cavity are located within the mediastinum, a centrally located area within the thoracic cavity.

External Anatomy of the Heart

Internal Anatomy of the Heart

Coronary Circulation

 On the posterior surface of the heart, the coronary artery branches to become the posterior interventricular artery  Near the apex of the heart the anterior and posterior interventricular arteries form an anastomosis (connection)

Coronary Circulation  On the posterior surface of the heart, the coronary sinus runs along the coronary sulcus and empties into the right atrium.  Great cardiac vein found in the anterior interventricular sulcus  Middle cardiac vein ascends along the posterior interventricular groove

Blood flow Through the Heart  Pulmonary Circulation- Blood from the right side of the heart flows to and from the lungs  Systemic Circulation- Blood from the left side of the heart flows from and to all body tissues.

Position of Heart  Base of the heart extends from the inferior border of the second costal cartilage on the left side to the superior border of the third costal cartilage on the right.  Apex of the heart is located in the left fifth intercostal space, left of the median plane

Today’s lab  Dissect sheep heart  ID structures on the heart models