What are the ten cranial nerves?
Cranial nerves; CN 0 – Terminal; CN I – Olfactory; CN II – Optic; CN III – Oculomotor; CN IV – ...
What nerve carries impulses toward the CNS?
What carries nerve impulses toward the CNS? Cranial nerves, spinal nerves, and ganglia make up the peripheral nervous system. The afferent division of the peripheral nervous system carries impulses to the CNS; the efferent division carries impulses away from the CNS. What transmits messages to CNS?
Are myelinated neurons only in the CNS?
There are two types of myelinated motor neurons on the basis of location: Upper Motor Neurons (UPNS) The upper motor neurons are present in the central nervous system (brain and spinal cord). The motor neurons of the CNS are myelinated by oligodendrocytes. Lower motor neurons (LMNs)
What are three types of cranial nerves?
The 12 Cranial Nerves
- I. Olfactory nerve. The olfactory nerve transmits sensory information to your brain regarding smells that you encounter.
- II. Optic nerve. ...
- III. Oculomotor nerve. ...
- IV. Trochlear nerve. ...
- V. Trigeminal nerve. ...
- VI. Abducens nerve. ...
- VII. Facial nerve. ...
- VIII. Vestibulocochlear nerve. ...
- IX. Glossopharyngeal nerve. ...
- X. Vagus nerve. ...
What nerves are in the CNS?
The central nervous system consists of the brain and spinal cord. It is referred to as “central” because it combines information from the entire body and coordinates activity across the whole organism....Right c1 spinal nerve.Right c1 spinal nerve branch.Left c1 spinal nerve.Left c1 spinal nerve branch.
Why are cranial nerves part of the PNS?
Cranial nerve ganglia originated in the CNS. However, the remaining ten cranial nerve axons extend beyond the brain and are therefore considered part of the PNS. The autonomic nervous system exerts involuntary control over smooth muscle and glands.
Are nerves part of the CNS?
The main parts of the nervous system are: Central nervous system (CNS): Your brain and spinal cord make up your CNS. Your brain uses your nerves to send messages to the rest of your body.
What consists of the CNS?
The central nervous system is made up of the brain and spinal cord. The peripheral nervous system is made up of nerves that branch off from the spinal cord and extend to all parts of the body.
What is the difference between CNS and PNS?
The central nervous system (CNS) includes the brain and spinal cord, while the peripheral nervous system includes all of the nerves that branch out from the brain and spinal cord and extend to other parts of the body including muscles and organs.
Which of the following is not part of the CNS?
Neuronal cell body of a sensory afferent is not part of the central nervous system.
Which does not belong to the peripheral nervous system?
Answer and Explanation: The b. brain is NOT a part of the peripheral nervous system. The brain, brain stem and spinal cord are all components of the central nervous system...
What is CNS responsible for?
The central nervous system (CNS) controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord. The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement.
Overview
Cranial nerves are the nerves that emerge directly from the brain (including the brainstem), of which there are conventionally considered twelve pairs. Cranial nerves relay information between the brain and parts of the body, primarily to and from regions of the head and neck, including the special senses of vision, taste, smell, and hearing.
The cranial nerves emerge from the central nervous system above the level of the first vertebrae …
Anatomy
Most typically, humans are considered to have twelve pairs of cranial nerves (I–XII), with the terminal nerve (0) more recently canonized. The nerves are: the olfactory nerve (I), the optic nerve (II), oculomotor nerve (III), trochlear nerve (IV), trigeminal nerve (V), abducens nerve (VI), facial nerve (VII), vestibulocochlear nerve (VIII), glossopharyngeal nerve (IX), vagus nerve (X), accessory nerve (XI), and the hypoglossal nerve (XII).
Development
The cranial nerves are formed from the contribution of two specialized embryonic cell populations, cranial neural crest and ectodermal placodes. The components of the sensory nervous system of the head are derived from the neural crest and from an embryonic cell population developing in close proximity, the cranial sensory placodes (the olfactory, lens, otic, trigeminal, epibranchial and paratympanic placodes). The doble-origin cranial nerves are summa…
Function
The cranial nerves provide motor and sensory supply mainly to the structures within the head and neck. The sensory supply includes both "general" sensation such as temperature and touch, and "special" senses such as taste, vision, smell, balance and hearing. The vagus nerve (X) provides sensory and autonomic (parasympathetic) supply to structures in the neck and also to most of the organs in the chest and abdomen.
Clinical significance
Doctors, neurologists and other medical professionals may conduct a cranial nerve examination as part of a neurological examination to examine the cranial nerves. This is a highly formalised series of steps involving specific tests for each nerve. Dysfunction of a nerve identified during testing may point to a problem with the nerve or of a part of the brain.
A cranial nerve exam starts with observation of the patient, as some cranial nerve lesions may a…
History
The Graeco-Roman anatomist Galen (AD 129–210) named seven pairs of cranial nerves. Much later, in 1664, English anatomist Sir Thomas Willis suggested that there were actually 9 pairs of nerves. Finally, in 1778, German anatomist Samuel Soemmering named the 12 pairs of nerves that are generally accepted today. However, because many of the nerves emerge from the brain stem as rootlets, there is continual debate as to how many nerves there actually are, and how they sh…
Other animals
Cranial nerves are also present in other vertebrates. Other amniotes (non-amphibian tetrapods) have cranial nerves similar to those of humans. In anamniotes (fishes and amphibians), the accessory nerve (XI) and hypoglossal nerve (XII) do not exist, with the accessory nerve (XI) being an integral part of the vagus nerve (X); the hypoglossal nerve (XII) is represented by a variable number of spinal nerves emerging from vertebral segments fused into the occiput. These two n…
See also
• Cranial nerve mnemonics