Sucking Reflex: Function, Tasks, Role & Diseases

The sucking reflex refers to an innate (in medicine, unconditional) reflex recorded in a wide range of mammals – humans being one of them. Normally, however, this reflex is unlearned during adolescence. In humans, this usually happens within the first year of life.

What is the sucking reflex?

When breastfeeding at the mother’s breast, the sucking reflex causes the baby to suck breast milk from the breast. By the sucking reflex, medicine and biology understand an unconditional and therefore innate reflex that is present in most mammals. Normally, this reflex is lost during adolescence. How long it is present, however, depends on the type of mammal. In humans, the reflex usually begins to weaken towards the end of the first year of life. In a child, for example, the sucking reflex is triggered when the lips and the tip of the tongue are touched. If this is the case, the infant begins to suck all by itself. When breastfeeding at the mother’s breast, for example, this ensures that the baby sucks the breast milk from the breast. In addition, the baby uses its tongue to exert pressure on the nipple and thus on the milk duct, which also forces the milk out. Only when feeding with the bottle is actually only sucked – however, in most cases, infants learn this quite quickly as well.

Function and task

The sucking reflex serves fundamentally to maintain the mammal in its youngest form. Its purpose is to ensure that the offspring is able to be fed even at the youngest age. For this reason, the sucking reflex is actually a natural reflex. That’s why infants, and babies of other mammalian species, suck or push immediately when something is brought to their mouths – such as a hand or a finger. The sucking reflex involves a whole range of muscles and nerves in the face and the rest of the body. The list of muscle groups that interact in the sucking reflex is long: probably the best known are the floor of the mouth muscles, the lip muscles, the cheek muscles and the tongue muscles. However, if the sucking reflex in an infant is disturbed or not present to a healthy degree, it becomes difficult to feed the infant, especially in the first months of life. This is because many of the body’s processes still take place subconsciously during this time. Meanwhile there are numerous aids for this. However, these do not always bring the desired success. The sucking reflex is fundamentally lost during adolescence when it is no longer needed to sustain life. This is the case, for example, when the boy or baby begins to take in other types of food besides breast milk. As a rule, the reflex is usually lost in humans within the first year of life. However, since the natural process of sucking is learned during this time, it is usually still possible to breastfeed or bottle-feed an infant without any problems afterwards.

Illnesses and complaints

A healthy and young baby is born with various unconditional reflexes and reactions. In humans, for example, these include reflexes and responses such as the sucking reflex, the grasping reflex, and the crying reflex. These reflexes all take place rather subconsciously and serve the growing up and, as with the sucking reflex, the survival of the baby. However, there are also cases and diseases in which the sucking reflex may be damaged, impaired or completely absent. In addition, the complexity of the swallowing and sucking processes means that they can be impaired by numerous diseases, for example of the musculature. One known disease of the musculature, which frequently affects the sucking and swallowing reflex, is myotonic dystrophy. This is genetically inherited, but according to current studies only occurs in 5 out of 100,000 cases. If, for example, there is damage or disease to the brain, there is sometimes impairment of the reflexes and therefore also of the sucking reflex. In addition, there are things like congenital suck weakness, where the sucking reflex is present but very weak. In addition, there may be defects in the swallowing reflex, which is very closely related to the sucking reflex and is also essential for an infant to survive. Medicine offers numerous ways and means to strengthen a weak sucking reflex or to be able to feed infants who do not have one.In the case of a weak sucking reflex, the child can be fed, for example, using special attachments or bottles with very soft teats that do not require too much squeezing and sucking. However, these do not always bring the desired success, especially in cases of severe damage or impairment of the sucking and swallowing reflex. Here, artificial feeding is often unavoidable.