Which substances would complete the equation that

The heart is a cone-shaped muscular organ located within the ________ of the thorax. its apex rests on the ___________ and its s

Arte-miy333 [17]

The heart is a cone-shaped muscular organ located within the mediastinum of the thorax.

The mediastinum is the space lined with membranous tissue between the lungs. The mediastinum contains not only the heart but also the great vessels (pulmonary artery, aorta, pulmonary veins, and the superior and inferior vena cava), as well as parts of the esophagus and the trachea.

Its apex rests on the diaphragm and its superior margin lies at the level of the 2nd rib.

The apex of the heart is the conical area created by the confluence of the ventricles, but mainly by the left ventricle. It rests on the diaphragm. The superior margin of the heart, also known as the base, lies at the level of the second rib.

Approximately two-thirds of the heart mass is seen to the left of the midsternal border.

This is because to the left of the midsternal border lies the left ventricle which comprises most of the heart mass as the left ventricle is the one responsible for pumping blood throughout the systemic circulation and significant pressure should be overcame; resulting to the physiologic hypertrophy of the left ventricle.

The heart is enclosed in a serosal sac called the pericardium. The loosely fitting double outer layer consists of the outermost fibrous pericardium, lined by the parietal layer of the serous pericardium.

The pericardium is one of three layers of the heart (other ones being the myocardium and the endocardium); and is the outer layer of the heart. The pericardium is composed of two tissues, the fibrous pericardium and the serous pericardium. The pericardium functions to lubricate the movement of the heart by the action of the pericardial fluid.

The heart has four chambers. Relative to the roles of these chambers, the atria are the receiving chambers, whereas the ventricles are the discharging chambers.

The four chambers of the heart are namely the right atrium, right ventricle, left atrium, and the left ventricle. Venous blood goes to the right atrium via the vena cavas then to the right ventricle via the tricuspid valve; then to the pulmonary circulation via the pulmonary artery where it will be oxygenated. From the pulmonary circulation, the left atrium will receive the oxygenated blood via the pulmonary veins then to the left ventricle via the mitral valve where it will be pumped to the systemic circulation via the aorta.

6 0

3 years ago

In which of the following situations would mass be conserved?

Butoxors [25]

Answer:

i guess option b is correct.

3 0

3 years ago

Read 2 more answers

Which will probably decrease population density?

-Dominant- [34]

The factor given in the choices that will probably decrease population density would be C. forest fire. Normal rainfall is beneficial to the ecosystem to help grow the vegetation and in result, benefits the consumers. Predators decrease the population while birth rate can also increase population.

3 0

3 years ago

When scientists assessed the ability of corn and tobacco to take up zinc from the environment, they found that different plant p

VikaD [51]

Answer:

Option D, leaves

Explanation:

The maximum concentration of zinc is accumulated both in the leaves and stem of corn and tobacco plants. But comparatively it is higher in the leaves than in the stem.

Zinc is a micro nutrient as it is required only in a small amount and it is found that plants will lesser zinc concentration dry out easily.

Also the relation between the zinc absorbed is linear to the accumulation of zinc in the leaves. Hence, the higher the zinc absorbed in the corn and tobacco plants, the higher is the zinc accumulating in the leaves.

Hence, option D is correct

3 0

3 years ago

What might a scientist do to determine evolutionary relationships among groups of organisms? (select all that apply.)?

Gennadij [26K]

When the idea of evolution originated, scientists used objects that were similar. An example being given would be that of monkeys and humans were much more alike than dogs and monkeys. When scientists realized how minor those differences were, it enabled them to study how close those relationships actually were. Public knowledge grew about cells and DNA; scientists also knew how it could be used to determine similarities and differences in proteins in humans and animals. Tying all of these methods together will create an evolutionary map.

3 0

3 years ago