Answer: B. pressure changes in the thorax
Explanation:
The veins are the blood vessels which returns the deoxygenated blood from all the tissues and cells of the body back to the heart. The ventricular systole, venous valves, activity of the skeletal muscles and neural control over venoconstriction all influence the movement of the blood in the venous.
The pressure changes in the thorax occurs due to inspiration and expiration. During the process of inspiration, the diaphragm below the lungs contracts and moves downward while the muscles of the ribs pulls downward. When the size of the thoracic cavity increase the air pressure inside the cavity decreases and vice-versa. The pressure inside the thoracic cavity is not related with the movement of the venous blood as it regulates the exchange of the gases not the blood.
When boys go through puberty their voices change and they start to grow hair on different area of their body such as their chest, face and pubic area. Also they will start to get acne
Cells that do a similar activity join together to shape body tissue, for example, muscle, skin, or bone tissue. Gatherings of various kinds of cells make up the organs in your body, for example, your heart, liver, or lungs. Every organ has own must do, however all organs cooperate to keep up your body.
Answer:
Question is not presented
Explanation: