Final answer:
To tell the difference between a vein and an artery, you should look for pulsations which are characteristic of arteries due to their higher blood pressure. Veins do not pulsate and carry blood back to the heart with less force. Venoconstriction affects blood pressure, flow within veins, and return of blood to the heart, hence the correct answer is all of the above.
Step-by-step explanation:
To differentiate between a vein and an artery, one can look for pulsations which are a sign of arteries. Veins do not pulsate like arteries because they don't have the same levels of blood pressure exerted by the heart's pumping. Arteries carry oxygenated blood away from the heart under high pressure, hence they pulse and can be felt on the body's surface at pulse points. Veins, on the other hand, carry deoxygenated blood back to the heart under low pressure.
When taking your pulse, you are feeling the force of blood as it is pushed through an artery during a heartbeat. This is why you cannot take your pulse using a vein; they simply don't have the same forceful blood flow that can be palpated. Pulse palpation typically uses superficial arteries like the radial or carotid.
Vasoconstriction, which means the constriction of veins, increases the blood pressure within the vein, blood flow within the vein, and return of blood to the heart.