Circulatory System

The unlikely similarity

A cow's heart is a bit bigger than a human's heart, due to it's massive body size. Thus, more power is needed so that blood could be pump to each and every part of the cow's body. But other than that, the heart of the cow is really the same as a human's. Parts from cattle hearts have also been used in human heart surgeries, hence showing how similar our hearts are.

The Heart

The heart of the cow has four chambers – two atria and two ventricles. This is the most efficient system, as deoxygenated and oxygenated bloods are not mixed. The right atrium receives deoxygenated blood from the body through both the inferior and superior vena cava. The blood then passes to the right ventricle to be pumped through the pulmonary arteries to the lungs, where it becomes oxygenated. It returns to the left atrium via the pulmonary veins, this oxygen-rich blood is then passed to the left ventricle and pumped through the aorta to the rest of the body. The aorta is the largest artery and has an enormous amount of stretch and elasticity to withstand the pressure created by the pumping ventricle. The four-chambered heart ensures that the tissues of the body are supplied with oxygen-saturated blood to facilitate sustained muscle movement. Also, the larger oxygen supply allows the cow maintain it's body temperature.

~MooMoo

The dissection of a cow's heart

Enjoy this short video first !!!

This photo shows the adult cow heart cut in cross section through the ventricles, with the smaller right ventricle at top and the larger left ventricle at the bottom.  The two are separated by the interventricular septum, and this example shows that the left ventricle's walls are much thicker.  Only the ventricles are visible in this photo.

From the right atrium, deoxygenated blood passes through the tricuspid valve into the right ventricle which pumps it to the lungs to pick up oxygen (and release carbon dioxide) in the adult.

This oxygenated blood returns to the left atrium via the pulmonary veins, passes into the left ventricle through the mitral valve , and is pumped out through the aorta to the body. Because the systemic circuit is long and has a high resistance to blood flow, the left ventricle must be very strong to pump at high pressure; this is why it is more thick even in the healthy individual.

This is a view of the cow heart showing the origin of the aorta. The first several inches of the aorta have been cut (on its long axis) to open it.  You can see the inside (lumen) of the aorta and where it exits the left ventricle of the heart.


The aortic valve has three leaflets, which result in the triangular appearance of the opening when it is partly open




This is a view of a ventricle opened to show one of the atrio-ventricular (AV) valves of the cow heart (the atrium has been mostly removed from the top in this view). The AV valves are found between the atria and the ventricles and ensure that blood flows in only one direction -- from the atrium to the ventricle.
The AV valves close when the right and left ventricles contract to expel blood into the pulmonary trunk (artery) and aorta, respectively.
The chordae tendinae are thin strands of connective tissue that anchor the leaflets of each AV valve so that they cannot open into the atrium (thus allowing backflow of blood into the atrium).

Hmmm.. interesting yeah ? never knew that i was sooo special ...

~MooMoo