What are different components of the facial nerve and their actions?
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What are different components of the facial nerve and their actions?
The facial nerve is the seventh cranial nerve. It contains the motor, sensory, and parasympathetic (secretomotor) nerve fibers, which provide innervation to many areas of the head and neck region….The facial nerve is comprised of three nuclei:
- The main motor nucleus.
- The parasympathetic nuclei.
- The sensory nucleus.
What are the 5 branches of the facial nerve?
The facial nerve then enters the parotid gland, and branches into five divisions (see above). The facial nerve has five main branches, although the anatomy can vary somewhat between individuals. The branches are, from top to bottom: frontal (or temporal), zygomatic, buccal, marginal mandibular, and cervical.
What is the difference between UMNL and LMNL?
An upper motor neuron lesion is a lesion of the neural pathway above the anterior horn of the spinal cord or motor nuclei of the cranial nerves. A Lower motor neuron lesion is a lesion which affects nerve fibers traveling from the anterior horn of the spinal cord to the associated muscle(s).
Why is upper face spared in UMN palsy?
An UMN lesion, therefore, causes unilateral facial palsy with some sparing of the frontalis and orbicularis oculi muscles because of the bilateral cortical representation. Furthermore, although voluntary facial movements are impaired, the face may still move with emotional responses, for example on laughing.
How do you remember the branches of the facial nerve?
There are many mnemonics to recall the branches of the facial nerve (superior to inferior) as they exit the anterior border of the parotid gland….Examples include:
- Tall Zulus Bear Many Children.
- Two Zebras Bit My Coccyx.
- Ten Zebras Buggered My Car.
- To Zanzibar By Motor Car.
- Two Zombies Buggered My Cat.
What cranial nerve is 7?
The facial nerve
The facial nerve is the seventh cranial nerve (CN VII). It arises from the brain stem and extends posteriorly to the abducens nerve and anteriorly to the vestibulocochlear nerve.
What is UMNL?
UMN lesions are designated as any damage to the motor neurons that reside above nuclei of cranial nerves or the anterior horn cells of the spinal cord. Damage to UMN’s leads to a characteristic set of clinical symptoms known as the upper motor neuron syndrome.
What are UMN signs?
Damage to upper motor neurons leads to a group of symptoms called upper motor neuron syndrome:
- Muscle weakness. The weakness can range from mild to severe.
- Overactive reflexes. Your muscles tense when they shouldn’t.
- Tight muscles. The muscles become rigid and hard to move.
- Clonus.
- The Babinski response.
Why is upper part of face spared in UMN lesion?
An UMN lesion, therefore, causes unilateral facial palsy with some sparing of the frontalis and orbicularis oculi muscles because of the bilateral cortical representation.
How can you tell the difference between upper and lower motor neuron lesions of the facial nerve?
A lower motor neurone lesion causes weakness of all the muscles of facial expression. The angle of the mouth falls. Weakness of frontalis occurs, and eye closure is weak. With an upper motor neurone lesion frontalis is spared, normal furrowing of the brow is preserved, and eye closure and blinking are not affected.
What are the 5 muscles of facial expression?
Oral Group?
- Orbicularis Oris- purses lips.
- Buccinator- pulls cheek inwards against teeth.
- Platysma- draws corners of mouth downwards.
- Other Oral Muscles- 2 groups that act on lips and mouth. – Lower group- contains depressor anguli oris, depressor labi inferioris and the mentalis.
