Among all body systems, the central nervous system occupies a special place. The brain regulates all the functions that a person is endowed with. Thanks to him, the relationship between the work of organs and systems is carried out. Without brain regulation, a person would not be a viable creature. Thanks to the coordinated activity of the central nervous system, we move, speak, think and feel external stimuli. The brain has a complex structure, each of its components is responsible for a specific function. Nevertheless, all its structures ensure the work of our body only in the aggregate. Particularly important formations that make up the CNS are the medulla oblongata and the pons. They contain the main vital centers (vascular, respiratory, cough, lacrimal), and also give rise to most cranial nerves.
Structure of the brain
The structural unit of the CNS is the neuron. It is this cell that is responsible for receiving, processing and storing information. The entire human brain is a cluster of neurons and their processes - axons and dendrites. They transmit signals to and from the CNS.to the organs. The brain is made up of gray and white matter. The first is formed by the neurons themselves, the second by their axons. The main structures of the brain are the hemispheres (left and right), the cerebellum and the brainstem. The former are responsible for the mental abilities of a person, his memory, thinking, and imagination. The cerebellum is necessary for coordination of movements, in particular, it provides the ability to stand straight, walk, take objects. Under it is the pons. It is the link between the medulla oblongata and the cerebellum.
Varoli's bridge: structure and functions
The pons is one of the parts of the hindbrain. Its length ranges from 2.4 to 2.6 cm. The bridge of Varolii has a mass of about 7 g. The structures that border it are the medulla oblongata and midbrain, the transverse sulcus. The main components of the pons varolii are the superior and middle cerebellar peduncles, which are major pathways. In front is the basilar sulcus, which contains the arteries that feed the brain, and next to it is the exit site of the trigeminal nerve. On the back of the varolii, the bridge forms the upper part of the rhomboid fossa, in which 6 and part 7 of the cranial nerves are laid. The upper part of the bridge contains the most nuclei (5, 6, 7, 8). At the base of the bridge there are descending pathways: corticospinal, bulbar and bridge tracts.
The main functions of this body:
- Conductor - along its paths nerve impulses pass to the cerebral cortex and to the spinal cord.
- Touchfunction - is provided by the vestibulocochlear and trigeminal nerves. In the nuclei of the 8th pair of cranial nerves, information about vestibular stimuli is processed.
- Motor - provides contraction of all facial muscles. This is due to the nuclei of the trigeminal nerve. In addition, its sensitive part receives information from the receptors of the mucous membrane of the mouth, eyeball, part of the head and teeth. These signals are sent along the fibers of the pons to the cerebral cortex.
- The integrative function ensures the relationship between the forebrain and hindbrain.
- Reflexes of the brain.
Reticular formation of the bridge
The reticular formation is a branched network located in the brain and consisting of nerve cells and nuclei. It is present in almost all formations of the central nervous system and smoothly passes from one department to another. The reticular formation of the pons is located between the medulla oblongata and midbrain. Its long processes - axons, form white matter and pass into the cerebellum. In addition, along the fibers of the nerve cells of the bridge, signals can be transferred from the head to the back. In addition, the reticular formation transmits signals to the cerebral cortex, due to which a person awakens or sleeps. The nuclei located in this part of the bridge belong to the respiratory center located in the medulla oblongata.
Reflex function of the bridge
The ability of the central nervous system to respond to external stimuli is calledreflex. An example is the appearance of salivation at the sight of food, the desire to sleep at the sound of soothing music, etc. Brain reflexes can be conditional and unconditional. The first person acquires in the process of life, they can be developed or adjusted depending on our desire. The second ones do not lend themselves to consciousness, they are laid down with birth, and it is impossible to change them. These include chewing, swallowing, grasping and other reflexes.
How the bridge affects the occurrence of reflexes
Due to the fact that the pons is an integral part of the quadrigemina, it is related to the development of the auditory and statistical reflex. Thanks to the latter, we are able to keep the body in a certain position. In addition, by interacting with the midbrain, it closes a significant part of muscle reflexes.
