Book contents
- Frontmatter
- Contents
- List of Figures
- List of Tables
- Acknowledgements
- A note to the reader
- Part I Organization of the cranial nerves
- Part II-V Individual cranial nerves and functional considerations
- 5 Survey of cranial nerves and introduction to Parts II–V
- Part II Trigeminal, facial and hypoglossal nerves
- Part III Glossopharyngeal, vagus and accessory nerves
- Part IV Autonomic components of cranial nerves, taste and smell
- Part V Vision, eye movements, hearing and balance: optic, oculomotor, trochlear, abducens and vestibulocochlear nerves
- Further reading
- Index
5 - Survey of cranial nerves and introduction to Parts II–V
Published online by Cambridge University Press: 25 August 2009
- Frontmatter
- Contents
- List of Figures
- List of Tables
- Acknowledgements
- A note to the reader
- Part I Organization of the cranial nerves
- Part II-V Individual cranial nerves and functional considerations
- 5 Survey of cranial nerves and introduction to Parts II–V
- Part II Trigeminal, facial and hypoglossal nerves
- Part III Glossopharyngeal, vagus and accessory nerves
- Part IV Autonomic components of cranial nerves, taste and smell
- Part V Vision, eye movements, hearing and balance: optic, oculomotor, trochlear, abducens and vestibulocochlear nerves
- Further reading
- Index
Summary
In the following chapters we consider cranial nerves in groups concerned with their functions. These are, in no particular order, ingestion and chewing, cutaneous sensation, swallowing and speaking, autonomic function, taste and smell, and sight, hearing and balance.
The ingestion of food is dependent on opening the mouth. This is a function of the mandibular division of the trigeminal (Vc) and facial (VII) nerves: the mandibular opens the jaw and the facial parts the lips. The facial, mandibular and hypoglossal (XII) nerves are involved in taking the food into the mouth and closing the lips. Chewing is served by the same three nerves: in simple language, the facial nerve keeps the lips closed, the mandibular nerve moves the mandible for its mastication, and both facial and hypoglossal nerves maintain the food between the teeth. Also, the trigeminal senses its position and consistency, and regulates the force of contraction of the muscles, and both trigeminal and facial nerves are responsible for taste perception from the mouth. The trigeminal nerve also has another important function: the cutaneous sensation of the face and anterior scalp. It is, except for a small area of skin in the external ear, the only nerve concerned with this. So, the trigeminal, facial and hypoglossal nerves will be considered first.
After we eat and chew, we swallow. The motor components of swallowing are mainly the responsibility of the vagus (X) and glossopharyngeal (IX) nerves, with the hypoglossal (XII) nerve also initially involved.
- Type
- Chapter
- Information
- Cranial NervesFunctional Anatomy, pp. 41 - 44Publisher: Cambridge University PressPrint publication year: 2005