For comparison, see heart dissections of a bat, a fox and a tree shrew.

We began the dissection by making a medial cut on the ventral side of the ferret. We started the cut medial to the shoulder and continued approximately one third of the length of the body. We reflected the pectoralis superficialis and profundus and cut through the sternum. Next we made three dorsoventral cuts along the medial cut to reflect the ribs.

The lungs were immediately visible after removing the ribs. The left lung had two lobes, called the cranial and caudal lobes, while the right lung had three major lobes and a fourth minor one [1]. The three major lobes are the cranial, middle, and caudal lobes, while the fourth lobe is called the accessory lobe [1]. The lungs were composed of extremely dark tissue. We removed the left lung to access the heart, and cut the pulmonary vessels in this process. We did not remove the right lung from the chest cavity but we cut the right pulmonary vessels to remove the heart. The pulmonary artery was distinguishable from the pulmonary vein because of the latex injection. The pulmonary artery was filled with blue latex, while the pulmonary vein was red.

Once we removed the left lung, the heart was clearly visible in the mediastinum. We observed and then removed the thymus, a fatty-looking gland, just superior to the heart. There was a thin layer of fat surrounding the heart in the pericardium that we also removed. The heart was approximately one-third of the distance between the front and rear limbs, starting at the sixth rib and continuing just caudal to the eighth rib. The heart of the ferret is cone-shaped with the apex of the cone caudal to the base. The apex of the heart is directed to the left of the median plane. The average weight of a female ferret's heart is 3.7 grams [1]. The heart was connected to the sternum by a ligament covered with fat. We cut this ligament, the pulmonary vessels, the aorta, and the vena cavae and removed the heart from the cavity. The ferret has one superior vena cava and one inferior vena cava. We observed the vena cavae after we cut them and removed the heart. The aorta gives rise to two major trunks, the brachiocephalic artery and the left subclavian artery.

After we removed the heart, we identified the coronary arteries by their red color in the heart tissue. We also identified the cardiac veins and the coronary artery based on their blue color on the surface of the heart muscle. We made a cut across the apex of the ventricles to observe the relative sizes of the heart walls. The left side of the heart had much thicker and more muscular walls than the right side of the heart. The left side needs to be stronger than the right side because the left side of the heart pumps blood to all of the body's tissues while the right side just pumps blood to the lungs. We cut the heart tissue and identified the right and left atria and right and left ventricles. The right atrium was larger than the left atrium. Compared to the ventricles, the walls of the atria were much thinner because they pump blood only into the ventricles while the ventricles have to pump blood a much greater distance. We did not find the atrial septum and the closed oval foramen because of the large amount of clotted blood that remained in the heart. The blood was black and tar-like and it stuck to the sides of the chambers despite thorough and repeated washings.

References:

1. Fox, J.G. 1998. Biology and Diseases of the Ferret (2nd Ed.). Williams & Wilkins, Baltimore.

2. Klingener, D. 1980. Laboratory Anatomy of the Mink (2nd Ed.). William C. Brown, Dubuque, Iowa.

Links:

to Comparative Mammalian Anatomy home

to mammalian hearts