222 ANATOMY FOR NURSES [Chap. XII 



cumstances, no pulse can be perceived by the touch or by 

 the eye. 



As each expansion of an artery is produced by a contraction of 

 the heart, the pulse, as felt in any superficial artery, is a convenient 

 guide for ascertaining the character of the heart's action. 



Locations where the pulse may be felt. — The pulse may be 

 counted wherever an artery approaches the surface of the body. 

 These locations are : — 



(1) The facial artery, where it passes over the lower jawbone. 



(2) The temporal artery, above and to the outer side of the outer 

 canthus of the eye. 



(3) The brachial artery, along the inner side of the biceps muscle. 



(4) The radial artery, on the thumb side of the wrist. On ac- 

 count of its accessible situation the radial artery is usually em- 

 ployed for this purpose. 



(5) The femoral artery, where it passes over the pelvic bone. 



(6) The dorsalis pedis, on the dorsum of the foot. 



Points to note in feeling a pulse. — In feeling a pulse the follow- 

 ing points should be noted. 



(1) Frequency, or the number of pulse-beats per minute. 



(2) Strength, or the force of the heart-beat. 



(3) Regularity, or the same number of beats per minute. 



(4) Equality. — Each beat should have the same force, not some 

 strong and some weak. It sometimes happens that a beat is missed 

 because the heart-beat is too weak to distend the artery. This is 

 called an intermittent pulse. 



Occasionally there is a lack of tone in the arterial walls and a 

 dicrotic pulse is felt. This means that the pulsations are divided 

 and the second part of the beat is weaker than the first. 



(5) Tension or the strength of the blood pressure. This is in- 

 dicated by the amount of force that is required to obliterate the 

 pulse. 



Average frequency of the pulse. — The average frequency of 

 the pulse in man is seventy-two beats per minute. This rate may 

 be increased after eating or by muscular action. Even the varia- 

 tion of the muscular effort entailed between the standing, sitting, 

 and recumbent positions will make a difference in the frequency 

 of the pulse of from eight to ten beats per minute. ^Mental excite- 

 ment may also produce a temporary acceleration, varying in degree 



