Tears come out while weeping

Why do tears come out while weeping?

            You must have noticed that whenever somebody weeps, tears begin to fall from his eyes. When someone is very happy even then tears come to his eyes. Do you know why it happens?

Falling of tears is a reflex action

            When we blink our eyes, many muscles come into play and the eyelids close and open just like stage curtains. The movement of the eyelids is so fast that it does not disturb our vision. The blinking of the eyes is an involuntary action that takes place every six seconds throughout our life.

            In each eye, there is a tear gland located at the outer corner. There are small tubes or ducts, which carry the tear to the upper eyelids, and from there they fall out of the eyes through other ducts.

            Every time we blink our eyes, some fluid comes out through the openings of the tear ducts. This keeps the eyes lubricated and prevents them from drying. When we weep, more fluid comes out through openings of the ducts in the form of tears. It is a reflex action that occurs without our control.

            Some times tears come out even when we laugh a great deal. That is because, when we laugh, the muscles squeeze the tear glands, due to which tears begin to flow out.

            Tears also come to our eyes when we cut onions because the onion gives off and irritating volatile substance. When it reaches our eyes, tears are produced to protect the eye from irritation. The tears wash the irritating substance away. The same thing happens in the case of smoke.

            Some sad news also produces tears by reflex action. This happens only when we do not have words to express our feelings.

What Causes a Reflex Action?

            If you accidentally touched a hot stove, what would you do? You would immediately jerk your had away even before you have had time to think about it. This action is called a reflex action. A reflex action is an automatic nervous action, in which a stimulus causes a rapid and totally involuntary response. In this case, the hot stove is a stimulus, and the jerk is the response.

Reflex Action

            Reflexes such as the pupil reflex are quite common. When a bright beam of light hits a person’s eye, his pupil automatically becomes smaller, i.e., it contracts. When the light is taken away and his eyes are shaded, the pupils return to their normal size. In this example, the light is the stimulus and the reaction of the pupil is the response.

            Reflex actions re of two types- unconditioned ad conditioned. Unconditioned reflex actions re exemplified by the reflex tests of the physician. When a doctor tests a person’s reflexes, he makes sure that the different parts of his nervous system are functioning properly.

            One reflex action frequently tested is the knee-jerk action. In this, the doctor lightly strikes an area just below the kneecap with rubber hammer. This cases the lower part of the leg to jerk upward suddenly. This is because the nerve impulses move via the spinal cord directly to the leg muscle and are not controlled by the brain.

             Conditioned reflex actions are a result of particular internal or external stimuli. The Russian physiologist Ivan Pavlov and his associates popularized such conditioning process. Pavlov believed that whenever there was a response to a particular stimulus, a kind of reflex was established in the brain. However, most psychologists today believe that the mechanism of learning is much more complicated than what was explained by him.

            Now the question arises- what cause a reflex action?

            To explain it in simple terms, four basic processes are involved in a reflex action. These are- reception, conduction, transmission, and response. The stimulus is received by receptors nerve ending. Energy from the stimulus is changed into nerve impulses and carried from the receptor to the central nervous system. The nerve impulses are then sent to the motor nerves. The motor nerves control muscle action, causing the muscles and gland respond. Most reflex actions, however, are much complicated and also involve other parts of the nervous system, like the brain. More than 90% of all our actions are performed by our nervous system, through reflex actions.