Structure and Functions of the Heart

Which of the following brings back deoxygenated blood to the Right Atrium?

• Coronary artery.

• Pulmonary vein.

• Vena cava.

• Aorta.

Answer explanation

The vena cava is the largest vein which consist of the superior and inferior vena cava. The vena cava transport deoxygenated blood from the upper and lower portion of the body at low pressure. The vena cava being a vein posses Valves which prevent backflow of bood.

Which of the following describes the function of arteries related to the heart? except the coronary artery.

• The arteries transport blood to the heart.

• The arteries transport blood away from the heart.

• The arteries transport blood inside of the heart.

• The arteries transport blood into the heart.

Answer explanation

Arteries transport blood away from the heart as they contain high blood pressure which enable them to transport blood to both the upper and lower portion of the body.

What characterizes Blood that leaves the heart?

• Oxygenated Blood with high pressure.

• Deoxygenated Blood with high pressure.

• Oxygenated Blood with low pressure.

• Both deoxygenated and oxygenated Blood with high pressure.

Answer explanation

The blood that leaves the heart are pumped out by ventricles which produces a high blood pressure since they posses thick cardiac walls. Both deoxygenated and oxygenated blood is pumped out via the pulmonary artery for doxygenated blood and the aorta for oxygenated.

Which of the following is has the thickest cardiac wall?

• The right atrium.

• The left ventricle.

• The Right ventricle.

• The left atrium.

Answer explanation

the left ventricle has the thickest cardiac muscle since it is required to pump blood to the systemic circulation that is throughout the body.

What prevents the backflow of blood between the Right ventricle and the right atrium?

• Semi lunar valves.

• The pressure exerted during atrial systole.

• The entry of blood into the Right atrium.

• The tricuspid valve.

Answer explanation

The tricuspid Valve is an atrioventricular valve separating the Right atrium and the right ventricle. The ticuspid valve prevent back flow as blood accumulates in the Right ventricle.

Label the following diagram of the heart.

Answer explanation

1. Pulmonary Artery.

2. Aorta.

3. Left Atrium.

4. Left ventricle.

5. Right ventricle.

6. Right atrium.

State the path of blood inside the heart and explain the how the heart is suited to carry out this function?

Answer explanation

The heart is a large muscular organ which constantly pushes oxygen-rich blood to the brain and extremities and transports oxygen-poor blood from the brain and extremities to the lungs to gain oxygen. Blood comes into the right atrium from the body, moves into the right ventricle and is pushed into the pulmonary arteries in the lungs. After picking up oxygen, the blood travels back to the heart through the pulmonary veins into the left atrium, to the left ventricle and out to the body's tissues through the aorta. The heart is a muscular organ. Its function is to pump blood. The right side pumps blood through the pulmonary circuit, while the left side pumps blood through the systemic circuit.

A septum separates the right and left sides. The left side has thicker walls because it needs to put the blood under higher pressure than the right side. The heart contains valves to prevent the blood flowing backwards:

the right side has a tricuspid valve (a valve with three flaps)

the left side has a bicuspid valve (a valve with two flaps). Both sides have semi-lunar valves (at the entrances to the pulmonary artery and aorta).

Explain using an example, how and why deoxygenated blood is keep separated from oxygenated blood?

Answer explanation

Deoxygenated blood is on the right side of the heart and oxygenated blood is on the left. Ordinarily, the walls (septum) of the heart keep them separate. However… there are congenital conditions (too many to go into here) in which they’re not separated and deoxygenated blood bypasses the lungs or deoxygenated and oxygenated blood inadvertently gets mixed and gets passed out to the rest of the body - also known as “blue baby syndrome” since the lack of proper oxygenation makes the skin appear blue.

Tags

NGSS.HS-LS1-2

NGSS.HS-LS1-3