Is cranial nerve 7 sensory or motor?
The two 7th Cranial Nerves (CN VII) are located on either side of the brainstem, at the top of the medulla. They are mixed cranial nerves with BOTH sensory and motor function. CN VII controls the face and is mainly FACE MOVEMENT with some face sensation.
What is the motor function of the 7th cranial nerve?
The facial nerve controls the muscles that help you smile, frown, wrinkle your nose, and raise your eyebrows and forehead. This seventh cranial nerve performs motor and sensory functions.
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 muscles does cranial nerve 7 innervate?
The principal muscles are the frontalis, orbicularis oculi, buccinator, orbicularis oris, platysma, the posterior belly of the digastric, and the stapedius muscle.
Where is the cranial nerve 7?
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue.
What is the difference between upper & lower motor neuron?
The upper motor neurons originate in the cerebral cortex and travel down to the brain stem or spinal cord, while the lower motor neurons begin in the spinal cord and go on to innervate muscles and glands throughout the body.
Why is the forehead spared in UMN lesions?
In a UMN lesion, the upper facial muscles are partially spared because of alternative pathways in the brainstem, ie the patient can wrinkle their forehead (unless there is bilateral lesion) and the sagging of the face seen with LMN palsies is not as prominent.
What are upper and lower motor lesions?
Lower motor neurons are in your brain stem and spinal cord. When they get a signal from the upper motor neurons, they send another signal to your muscles to make them contract. Lesions are areas of damage to motor neurons. Damage to upper motor neurons stops the signals your muscles need to move.
How do you assess cranial nerve 7?
Cranial nerve VII controls facial movements and expression. Assess the patient for facial symmetry. Have him wrinkle his forehead, close his eyes, smile, pucker his lips, show his teeth, and puff out his cheeks. Both sides of the face should move the same way.
What cranial nerve is 7?
Facial Nerve
Facial Nerve (Cranial Nerve VII) — General Information. General: Cranial nerve seven (CN VII) is responsible for both efferent and afferent modalities in the head and neck including: Branchial motor fibers that innervate: muscles of “facial expression”
What is 7th cranial nerve called?
The facial nerve
The facial nerve is the 7th cranial nerve and carries nerve fibers that control facial movement and expression. The facial nerve also carries nerves that are involved in taste to the anterior 2/3 of the tongue and producing tears (lacrimal gland).
How can you tell the difference between upper and lower motor neurons?