![]() Identify the entrance to the aorta and probe it from the inside of the left ventricle.Ĭompare the right and left ventricles with regard to their respective sizes and the thickness of the myocardium. Examine the endocardium and the mitral valve (Figure 5.15). The valve between the left atrium and ventricle has two cusps and is termed the bicuspid or mitral valve (miter = type of hat that tapers to a point). Left atrium and ventricleĬut open the left atrium and ventricle through the entrance for the pulmonary vein into the left atrium (Figure 5.14). Note the papillary muscle and chordae tendineae.Ĭan you trace the blood flow out of the right ventricle? What organ is the first to receive this blood? 7. One of the cusps of the tricuspid valve, held up by a finger. Image by Karolinska Institutet / CC BY 4.0 Figure 5.13. Image by Karolinska Institutet / CC BY 4.0 Figure 5.12. Finally, identify the pulmonary valve and probe it from the inside of the ventricle. Proceed to examine the muscular wall of the ventricle and take note of the trabeculae carneae (beam-like structures). Observe and palpate the valve (Figure 5.13). This valve has three cusps, which are attached to papillary muscles extending from the inner wall of the ventricle. Open the right ventricle and take note of the valve (Figure 5.12). You will then cut through the tricuspid valve. The right ventricleĬut open the right ventricle through the opening from the right atrium, along the right side of the heart (Figure 5.11). How would a patent (open) foramen ovale affect the range of possible outcomes? 6. They may give rise to a thromboembolism, when part of a blood clot comes off, and is transported by the blood to some other part of the body thus blocking the blood flow. Probing of the fossa ovalis.ĭeep venous thromboses are not uncommon. Image by Karolinska Institutet / CC BY 4.0 Figure 5.10. Image by Karolinska Institutet / CC BY 4.0 Figure 5.9. Find the fossa ovalis and examine with a probe whether any opening remains (Figure 5.10). Sometimes, a small opening may persist, and is then termed a patent foramen ovale. This opening normally closes at birth, leaving a shallow pit-fossa ovalis-in the myocardium. Also notice the pectinate muscles.ĭuring fetal life, when lungs are not used for gas exchange, there is an opening-foramen ovale. ![]() Take note of the smoothness of the endocardium, the tissue lining the inside of the heart. Remove any coagulated blood that may be found here. Cut open the right atrium along the path between the vena cavae openings and continue into the auricle (Figure 5.9). Identify the openings for the superior and inferior vena cavae (Figure 5.8). How much of the heart appears to receive its blood supply from only one single artery? 5. The anatomy of the coronary vessels may vary greatly between individuals. The effect of diminished flow in one coronary artery depends on, among other things, whether other arteries can compensate for the decreased flow. In angina or myocardial infarction, the myocardium (heart muscle) receives insufficient blood flow. Try pouring a little water on the valve and see if the valve closes. The aortic valve and base of the pulmonary artery. ![]() Inspect the valves and palpate them (feel them with a finger). The aortic and pulmonary valves are each made up of three leaflets. Identify the aorta and the pulmonary artery and then cut them to make the valves visible (Figure 5.4). It may be necessary to remove excessive tissue to visualize structures and for ease of dissection. ![]() Several vessels extend from the superior (topmost) side of the heart. It has been speculated that they function as reservoirs for blood, which may be mobilized in times of increased physiological need. The auricles are appendages to the atria. You also may find cuts that have been made when the heart was removed from the chest cavity. The heart commonly has some adipose tissue on the outer surface. Image by Karolinska Institutet / CC BY 4.0 Entrances of superior vena cava and inferior vena cavaįigure 5.3.Demarcation between the right and the left ventricle (interventricular septum).Specimens may or may not have been perfused with a preservative that will cause a different heart color than shown. Surface anatomy of the heartīegin by orienting the heart (Figure 5.3). Images by Karolinska Institutet / CC BY 4.0 2. Forceps and scissors (including vascular scissors) are best held as shown here, as these grips give good control. Image by Karolinska Institutet / CC BY 4.0įigure 5.2. Identify internal anatomical structures of the heart.ġ.Identify external anatomical structures of the heart. ![]() Demonstrate proficient dissection skills. ![]()
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