1.
What heart action incorporates relaxation?
Correct Answer
B. Diastole
Explanation
Diastole is the correct answer because it refers to the phase of the cardiac cycle when the heart muscle relaxes and fills with blood. During diastole, the chambers of the heart expand and the blood flows into them, allowing for the next contraction (systole) to occur. This relaxation phase is crucial for the heart to rest and refill with oxygenated blood before pumping it out to the rest of the body.
2.
How many chambers are there in the heart?
Correct Answer
C. Four
Explanation
The heart has four chambers: two atria and two ventricles. The atria receive blood from the body and lungs, while the ventricles pump blood out to the body and lungs. This division of chambers allows for efficient circulation of oxygenated and deoxygenated blood throughout the body.
3.
Which carry blood away from the heart?
Correct Answer
C. Arteries
Explanation
Arteries carry blood away from the heart. They have thick, muscular walls that allow them to withstand the high pressure of blood being pumped by the heart. As the heart contracts, it pushes oxygenated blood into the arteries, which then distribute the blood to various parts of the body. This oxygenated blood is essential for delivering nutrients and oxygen to the body's tissues and organs.
4.
What are the pumping chambers of the heart?
Correct Answer
A. Right and left ventricles
Explanation
The pumping chambers of the heart are the right and left ventricles. The ventricles are responsible for pumping blood out of the heart and into the arteries. The right ventricle pumps deoxygenated blood to the lungs, while the left ventricle pumps oxygenated blood to the rest of the body. The atriums, on the other hand, receive blood returning to the heart. The pulmonary trunk is a blood vessel that carries blood from the right ventricle to the lungs.
5.
Which is a circulation system of the blood?
Correct Answer
D. All of the above
Explanation
The correct answer is "all of the above" because pulmonary, systemic, and coronary are all circulation systems of the blood. The pulmonary system is responsible for carrying blood between the heart and the lungs, the systemic system carries blood between the heart and the rest of the body, and the coronary system supplies blood to the heart muscle itself. Therefore, all three options are correct circulation systems of the blood.
6.
Which is the deepest layer of the arteries?
Correct Answer
B. Tunica interna
Explanation
The tunica interna is the innermost layer of the arteries, also known as the intima. It is composed of a single layer of endothelial cells that line the inside of the artery. This layer is responsible for maintaining the smooth flow of blood and preventing clotting by releasing substances that inhibit platelet aggregation. It also plays a role in regulating blood pressure and controlling the exchange of nutrients and waste products between the blood and surrounding tissues.
7.
Which decreases the diameter of the artery?
Correct Answer
A. Vasoconstriction
Explanation
Vasoconstriction is the process of narrowing or constricting the diameter of an artery. This occurs when the smooth muscle in the walls of the artery contracts, causing the artery to become narrower. As a result, the blood flow through the artery is reduced. Vasoconstriction can be caused by various factors such as hormones, neurotransmitters, and certain medications. It is a physiological response that helps regulate blood pressure and redirect blood flow to specific areas of the body.
8.
Which layer of the veins is poorly developed?
Correct Answer
C. Middle
Explanation
The middle layer of the veins is poorly developed. This is because veins are composed of three layers: the inner layer (tunica intima), the middle layer (tunica media), and the outer layer (tunica adventitia). The middle layer of veins is thinner and less muscular compared to arteries. This is because veins are responsible for carrying blood back to the heart, and they do not experience the same high pressure as arteries. Therefore, the middle layer of veins is less developed and less prominent than the other layers.
9.
The maximum pressure during ventricular contraction is
Correct Answer
B. Systolic pressure
Explanation
The maximum pressure during ventricular contraction is known as systolic pressure. This is the highest pressure exerted on the walls of the arteries when the heart pumps blood into the circulation. The systolic pressure is measured as the top number in a blood pressure reading, and it represents the force exerted by the heart when it contracts. This pressure is important in assessing cardiovascular health and can indicate conditions such as hypertension or heart disease.