The word "pulse" is derived from the Latin word pulso, "I strike" and denotes the striking or lifting of the finger by the distending vessel, as with each contraction of the heart blood is forced into the vessels.

The word pulse has also been applied to the appearance of a lifting up of the coverings over a distending vessel, so that this word "pulse" is applied not only to that which is felt, but to that which is seen.

There are two kinds of pulse, the arterial and the venous. The arterial is appreciated mainly by palpitation, the venous by inspection. It is the "arterial pulse," that it is necessary to study.

The "radial pulse" is the one usually selected, although the "temporal pulse" is also noted in the administration of anaesthetic agents. The pulse in other vessels must also sometimes be observed, as in the brachial, the facial in front of the masseter muscle, the posterior tibial, the dorsalis pedis, the carotid and femoral arteries.

The "radial pulse," the one usually selected, and which, in most cases, answers all the requirements, is of moderate size, superficial, and can be readily compressed against the radius.

When the pulse is to be observed, the patient should be either sitting or lying down. The observer should place his index, middle, or ring finger lightly upon the pulse, and should then appreciate the state of the coats of the artery, and should next note the frequency, the rhythm, the tension, volume and force of the pulse; and, lastly, any peculiarities, if present. Moreover, the pulse of one side of the body should always be compared with the other.

It should also be remembered that forcible extension or flexion of the forearm will sometimes arrest the radial pulse.

In noting the pulse of children and infants, it is well to count the pulse, if possible, while they are asleep.

This can be conveniently done in the temporal artery.

In noting the pulse of the wrist, asleep or awake, there are often involuntary movements of the arm and twitching of the muscles, which render it difficult to keep the finger of the observer on the pulse. This difficulty may be overcome in a great degree by grasping the entire hand of the child, and then extending the index finger upon the pulse. It is also advisable not to take the pulse of the patient until some little time has elapsed after the appearance of the observer. In health, changes in the frequency and rhythm of the pulse are often met with. The normal pulse in an adult is about 75 beats per minute, while in infants it ranges from 120 to 140 beats per minute; and the very old have a much higher pulse-rate than those of middle age.

The following is a table of the variations in the frequency of the pulse in health: -

Infant asleep, at birth............... 140

Infancy.................... 120

Child under 5 years of age..............100

Youth ......................90

Male adults....................72-80

Female adults.................. 80-85

Old age......................70

It is only in rare cases that great frequency of the pulse in health is met with. Sex has some influence. Up to the 7th year of age the frequency is about the same in both sexes, but later the female is from 6 to 14 beats - average 9 - greater than in the male.

Posture also affects the pulse. It is most frequent in the standing, and least in the recumbent position.

The pulse of a man is twice as much affected by change of position as that of a woman.

When the pulse is much increased in frequency, change in position has but little effect, and for the higher numbers entirely disappears. When the head is lower than the body, the pulse falls. The general law as to the degree of frequency of the pulse, as affected by position, is as follows: -

The frequency is directly proportionate to the amount of muscular effort required to support the body in different positions. The pulse falls in sleep, as much as ten beats. Sleeplessness increases its frequency. On awakening from sleep, there is usually a decided increase in frequency. Food increases the rate of the pulse. Mental excitement and activity of the emotions increases the frequency ; mental depression is often accompanied by a decrease. Cold lowers and heat raises the rate of the pulse. Among other causes producing an increase in the frequency of the pulse in health, are spirituous and warm drinks, tobacco, diminished atmospheric pressure. Among other causes producing diminished frequency of the pulse, besides those before mentioned, are fatigue, long-continued rest, debility without disease, and increased atmospheric pressure.

Occasionally the pulse is irregular in health, but when it is so, it is usually congenital. Intermittency is not infrequent in health, and it is then either congenital or may be due to terror, anxiety, grief, mental or physical fatigue, and old age. The intermittency may be only temporary, or it may become permanent; and if it becomes very frequent, may be pathological.

A pulse of 90 or more may be regarded as a pulse of abnormal frequency in an adult. There are exceptions to this, but they are rare. If the pulse is quicker than the temperature will explain, it indicates cardiac weakness.

A pulse that day by day progressively increases, the temperature remaining the same, shows increased cardiac weakness. In all febrile diseases, a pulse, in adults, over 120 is serious, and indicates cardiac weakness. A pulse of 130 or 140 indicates great danger; and with a pulse at 160, the patient almost always dies.

Under the age of fifteen, any disease of the lungs is almost invariably accompanied by great frequency of the pulse, so that a pulse of 120 to 140 would not be considered as so serious in significance as if it occurred in an older person.

A soft, rapid, small pulse indicates great weakness, and an irregular or intermittent pulse indicates functional or organic disease of the heart.

A pulse of 120 in a strong, robust patient affected with pneumonia, indicates some form of heart-disease. When pneumonia occurs in the cachectic or debilitated, the pulse is usually very frequent, often 120 to 160, and such cases usually die. In pericarditis and myocarditis, there is great frequency of the pulse, especially on any movement of the patient - 130 to 160 - and the change may be very sudden. In acute articular rheumatism, unaccompanied by any heart disease, a pulse of 120 or more indicates great danger. In pleuritic effusions, the pulse may be very frequent, especially when there is displacement of the heart.

Respiration At Various Stages

At one year of age, per minute........... 35

" two years of age " " ............ 25

" puberty " " ............ 20

" adult age, " " . .......... 18