Hope McLaughlin, age 15, of Hattesburg, Miss., for her question:
HOW CAN YOU FEEL A PERSON'S PULSE?
Pulse is caused by the stretching of the arteries that takes place after each heartbeat. The stretching comes as blood moves through the body. You can feel a person's pulse by placing your fingers on the wrist above the thumb at a point over the radial artery.
The pulse can also be felt by gently touching the temples where the temporal artery is located, and also at other places on the hody where an artery is near the surface. These. are called pulse points.
Each heartbeat consists of a contraction of the muscles of the heart that pushes the blood into the arterial system, followed by a period of relaxation during which the heart refills. As the heart contracts, the blood is pumped into the aorta and pulmonary arteries.
The aorta, the largest artery in the body, carries the blood aerated in the lungs from the left side of the heart to the rest of the body. As the blood rushes into the aorta, its elastic walls are stretched and it expands to make room for the blood.
As the blood moves on to enter the arteries that branch off from the aorta, the walls relax and it contracts to normal size. The walls of these arteries and of their branches also expand and contract as the blood passes through them.
The expansion of the arteries causes a pulsation known as the pulse.
The pulse rate of children is faster, and that of old people often is slower than that of the average healthy adult. While pulse rates between 50 and 85 per minute are considered within normal limits, the normal rate for the average man is about 72. The pulse rate of the average woman is a little faster at 76 to 80 per minute. The pulse rate of a newborn child may be as high as 140 per minute. The normal rate for a 7 year old child is about 90 per minute.
Slower rates of from 50 to 65 per minute are not unusual in old age. But regardless of a person's age, both the pulse rate and heart rhythm are very important and should be very regular.
A doctor feels a patient's pulse to find out if the heart is beating normally. If the pulse is too fast or too slow, or if the pulse is irregular, the doctor examines the patient to find the cause of the abnormal heart beat.
There are many examples of how the heart changes its rate of beating to meet particular needs. The body needs a lot of fuel for such strenuous exercises as playing baseball or riding a skateboard. For this reason, the heart beats rapidly when a person is involved in heavy exercising. The heart is rushing more oxygen to the body by speeding the flow of blood.
When a person stops exercising, his heart soon slows down to normal. The beat of the heart increases when a person is angry, afraid or excited. It is rushing more oxygen to his muscles to prepare him for fighting or for running away.