How many cranial nerves are there?
The cranial nerves are an important part of the peripheral nervous system. They mainly supply the head and the neck and shoulder area in a sensitive, motor and sensory way. But how many cranial nerves are there actually?
This is what we mean by cranial nerves
- The nervous system is divided into central and peripheral nervous systems. The central nervous system consists of the brain and the spinal cord. The peripheral nervous system includes the twelve pairs of cranial nerves and the spinal nerves (spinal cord nerves), which branch out.
- There are both motor and sensory nerves. The motor muscles cause the muscles to contract, the sensitive ones create sensations. The sensory nerves are responsible for sensory impressions. A distinction is also made between the voluntary and the vegetative nervous system, which is formed from the parasympathetic and sympathetic nervous system.
There are so many pairs of nerves
The question of how many cranial nerves there are can be answered clearly: there are twelve in number.
- The 1st The cranial nerve is the olfactory nerve. It is the olfactory nerve, i.e. a purely sensory nerve. It forwards its signals to the olfactory brain.
- The second. The cranial nerve is the optic nerve, the optic nerve, which is also purely sensory. It directs optical impressions to the visual center.
- The 3rd Cranial nerve, the oculomotor nerve. As the name suggests, it moves four of the six outer eye muscles and the eyelid elevator muscle. It is mainly a motor nerve, but also has parasympathetic parts.
- The 4th The cranial nerve is the trochlear nerve, a motor nerve that supplies one of the other two external eye muscles.
- The 5th The cranial nerve is the trigeminal nerve. It is so called because it consists of three parts. The first part sensitively supplies the eye socket and the forehead, the second part also supplies them sensitively skin of the upper face, the third part sensitively supplies the lower jaw area and motorized the masticatory muscles and the floor of the mouth.
- The 6th The cranial nerve, the abducens nerve, supplies the last of the outer muscles of the eye.
- The 7th The cranial nerve, the facial nerve, has motor, sensory and parasympathetic parts. It supplies the facial muscles with motor and is sensory for the taste sensation of the front two thirds of the tongue and parasympathetically responsible for the function of the lacrimal glands and some salivary glands.
- The 8th The cranial nerve is the vestibulocochlear nerve. This sensory nerve forwards the information from the auditory and equilibrium organs.
- The 9th The cranial nerve is called the glossopharyngeal nerve. It innervates the throat muscles by motor and the back third of the tongue by sensory means, where the taste is perceived as bitter. This causes the muscles in the throat to gag when eating bitter foods (which could be poisonous). This cranial nerve innervates the parotid gland in a parasympathetic manner.
- The 10th The cranial nerve is the vagus nerve, which is the main nerve of the parasympathetic nerve. This cranial nerve is the only one that leaves the head and neck area and pulls down the trunk. It also has some sensory and motor parts.
- The 11th The cranial nerve is the accessory nerve. This motor innervates the hood muscle as well as the Neck muscles.
- The 12th. Finally, the cranial nerve is the hypoglossal nerve, the tongue nerve that supplies the tongue with motor.
The nervous system is an infinitely important part of the human organism - ...
The question of how many cranial nerves there are should be correctly answered with 24, since all cranial nerves are paired. One therefore usually speaks of the 12 pairs of cranial nerves.
The content of the pages of www.helpster.de was created with the greatest care and to the best of our knowledge and belief. However, no guarantee can be given for the correctness and completeness. For this reason, any liability for possible damage in connection with the use of the information offered is excluded. Information and articles must under no circumstances be viewed as a substitute for professional advice and / or treatment by trained and recognized doctors. The content of www.helpster.de cannot and must not be used to make independent diagnoses or to start treatments.