Why can a pulse only be detected at certain places on the body?

Answer 1

A pulse is simply the stretching of the arterial walls caused by them filling with the blood of each heartbeat. This pulse occurs in all of the arteries, and for example if a surgeon exposed an artery during surgery, the surgeon would be able to feel the pulsations if the artery is large enough, however, as you get down to the the smallest arteries and the arterioles, it quickly becomes impossible to detect (at least manually).

Pulses are not detected only at certain areas, they are just simply more easily palpated (felt) at such locations. These are usually locations where the artery can be pressed against a bone or other relatively hard structure. In fact, while the most common places to check for a pulse are the neck (carotid), groin (femoral), upper arm (brachial), wrist (radial and ulnar), back of knee (popliteal), medial (inner) surface of ankle (posterior tibial), and the top of the foot (dorsalis pedis), pulses can be felt in a interesting variety of other places: In front of the ear (superficial temporal), on either side of the nose (facial), of course on the temple (temporal), the pharynx (internal carotid - DON'T even think about it, the gag reflex exists for a reason), behind the clavicle (subclavian), in the armpit (axillary), the thumb, the dorsal (top) surface of the penis (dorsal artery of the penis), and best of all, in relatively thin and lean individuals with softer abdominal muscles, the abdominal aorta.

It can be palpated around the navel, but still requires considerable pressure to be palpated. So if you possess a hard 6-pack, all bets are likely off. In addition, because of its possible danger, it should only be tried on persons who have not had any recent abdominal injury, surgery, or in anyone with a transplanted abdominal organ, or have blood pressure problems, fainting spells, or any abdominal or chest pain for that matter. In other words, it's best to only try it out on yourself.