1.
The main function of the vascular system is transportation.
Correct Answer
A. True
Explanation
The main function of the vascular system is indeed transportation. The vascular system, which includes the network of blood vessels, is responsible for transporting oxygen, nutrients, hormones, and other substances throughout the body. It also plays a crucial role in removing waste products from cells and tissues. Therefore, it can be concluded that the statement "The main function of the vascular system is transportation" is true.
2.
The blood accounts for about ______ of the total body weight.
Correct Answer
C. 8%
Explanation
The blood accounts for about 8% of the total body weight. This is because the average adult has approximately 5 liters of blood, which weighs around 8% of their total body weight. Blood is made up of red blood cells, white blood cells, platelets, and plasma, and it plays a vital role in transporting oxygen, nutrients, hormones, and waste products throughout the body.
3.
Blood viscosity refers to the thinness of the blood and its resistance to flow.
Correct Answer
B. False
Explanation
Blood viscosity refers to the thickness or resistance to flow of blood, not its thinness. A high blood viscosity means the blood is thicker and flows more slowly, while a low blood viscosity means the blood is thinner and flows more easily. Therefore, the statement that blood viscosity refers to the thinness of the blood is incorrect.
4.
After a period of endurance training the blood is redistributed less efficiently.
Correct Answer
B. False
Explanation
After a period of endurance training, the blood is actually redistributed more efficiently. This is because endurance training increases the efficiency of the cardiovascular system, resulting in improved blood circulation and oxygen delivery to the muscles. This allows for better endurance and performance during physical activities. Therefore, the statement that the blood is redistributed less efficiently after endurance training is false.
5.
Blood pressure = cardiac output x resistance
Correct Answer
A. True
Explanation
This statement is true because blood pressure is determined by two factors: cardiac output, which is the amount of blood pumped by the heart per minute, and resistance, which is the opposition to blood flow in the blood vessels. When the heart pumps more blood or when the resistance to blood flow increases, blood pressure increases. Therefore, the equation "blood pressure = cardiac output x resistance" accurately represents the relationship between these variables.
6.
The major roles of the lymphatic system are: (Select three)
Correct Answer(s)
A. To maintain appropriate fluid levels in the tissues.
C. To prevent excess swelling through the removal of fats and proteins.
D. To fight infection.
Explanation
The lymphatic system plays a crucial role in maintaining appropriate fluid levels in the tissues by collecting and returning excess fluid back to the bloodstream. It also helps to prevent excess swelling by removing fats and proteins from the tissues. Additionally, the lymphatic system is an important component of the immune system and helps to fight infection by producing and transporting white blood cells, antibodies, and other immune cells throughout the body.
7.
Blood is made up of blood cells and platelets floating in a liquid matrix called plasma.
Correct Answer
A. True
Explanation
Blood is composed of various components, including blood cells and platelets, which are suspended in a liquid called plasma. These blood cells include red blood cells, white blood cells, and platelets, each with their own specific functions. Plasma, on the other hand, is a yellowish fluid that carries these blood cells throughout the body, providing nutrients, hormones, and waste removal. Therefore, the statement that blood is made up of blood cells and platelets floating in a liquid matrix called plasma is true.