Considering how the body is organized, give one reason why it is so difficult for scientists to build a heart.

a)the heart is a pump made of muscle and that is difficult to grow in the lab.
b)even if researchers build a heart, there is no guarantee that a person's body will accept it.
c)human hearts are not like any other animal hearts so there is not source for cells and tissues.
d)the heart is made up of many different types of cells that are organized into different tissues.

An 80-year-old woman comes to the urgent care clinic with dyspnoea on exertion. on physical examination, her blood pressure is 100/70, and her pulse is 75. she has no pulsus paradoxus. her jugular veins are distended, and she has distant heart sounds. in addition, she has extra third and fourth heart sounds. her liver is enlarged, and she has pedal oedema. she has occasional premature ventricular contractions on her electrocardiogram. a chest x-ray reveals clear lung fields with a dilated cardiac silhouette. her echocardiogram reveals ventricular walls with a "speckled pattern". which of the following is the most likely diagnosis? - alcoholic cardiomyopathy- amyloidosis- haemochromatosis- tuberculosis- viral myocarditis