Task of the reflexes
Reflexes are reactions of the body to external stimuli that occur immediately and do not require any special control or readiness. This is possible as quickly as possible because the reflexes are based on a simple circuitry that directly causes a reaction to a stimulus. The strength and duration of the stimulus also plays a role.
There is therefore a stimulus-reflex relationship. Reflexes serve to protect the body. For example, early childhood reflexes facilitate the infant’s search for and intake of food.
Reflexes play an important role in defending against danger. Before a foreign body can enter the eye, for example, the eyelid closure reflex reacts and the eye is closed. When stepping into a pointed or sharp object, the affected foot is lifted reflexively and the other foot is loaded.
Some reflexes are therefore also called protective reflexes. Reflexes are also used to correctly learn and execute complex movement sequences during development. The innate reflexes enable a person to adapt to circumstances and survivability that does not have to be learned first.
What reflexes are there?
The reflexes are distinguished by the location of receptor and effector and the number of intermediate synapses. If receptor and effector are in the same organ, it is a simple reflex arc and is called an auto-reflex. If receptor and effector are in different organs, this is called extraneous reflex.
A distinction is made between innate and learned or acquired reflexes. The reflexes are divided into visceral, somatic and mixed reflexes. The somatic reflexes can be divided into reflexes with one synapse, so called self reflexes, and with several synaptic circuits, so called foreign reflexes.
Examples of monosynaptic self-reflexes are the patellar tendon or biceps tendon reflex. An example of a polysynaptic extraneous reflex is the reflex pullback reflex of the leg when stepping on a pointed object. Visceral reflexes control the function of the internal organs to certain conditions. For example, voiding the bladder is controlled by visceral reflexes, whereby the increasing filling of the bladder is the triggering stimulus in this case.Mixed reflexes are mixtures of visceral and somatic reflexes. An example of this is the effect of a warm object such as a hot water bottle on the skin of the abdomen, which has a relaxing effect on tense, irritated bowels.
