Cranial Nerves Flashcards
What number is the trigeminal nerve?
Cranial nerve 5
The trigeminal nerve is both a ______ and a _____ nerve
motor; sensory
What three branches does the trigeminal nerve include?
ophthalmic (sensory), mandibular (mixed), and maxillary (sensory)
What does the trigeminal nerve do?
It moves the muscles used for mastication and provide sensation to the head and face
Where does the ophthalmic branch of the trigeminal nerve pass through?
the superior orbital fissure found between the greater and lesser wings of the sphenoid bone
Where does the maxillary branch of the trigeminal nerve pass through?
the infraorbital foramen of the maxillary bone
Where does the mandibular branch of the trigeminal nerve pass through?
the foramen rotundum of the sphenoid bone
What is the difference between afferent and efferent?
afferent is to take information from sensory receptors and send it to the central nervous system. Efferent is to take information from the central nervous system to the muscles and glands in the body.
What does the ophthalmic branch do?
innervates the upper 3rd of the face, which includes eyeball, conjunctiva, nasal cavity, lacrimal gland, scalp up to the vertex
What does the maxillary branch do?
innervates the middle 3rd of the face, which includes most of the nasal cavity, upper teeth and gums, maxillary sinus, pharynx’s mucous membrane, palate, and dura mater of the middle cranial fossa
What does the mandibular branch do?
provides sensation to the lower part of the face including part of the auricle and temple; motor control for the muscles of chewing, mylohyoid, anterior belly of the digastric, tensor palati, and tensor tympani.
The mandibular nerve forms _____
both the limbs of masticatory reflex.
What is the tensor tympani?
muscle in the middle ear that decrease the amount of sound that enteres the middle ear.
What is the tensor palati?
muscle that helps the levator palatini in preventing food from entering the nasopharynx by tensing the soft palate
What is the masticatory reflex?
a kind of stretch reflex where muscles in the jaw are activated; thus causing the jaw to move
What is cranial nerve 1?
olfactory nerve
What is a nerve?
a bundle of fibers that uses chemical and electrical signals to send sensory and motor information
Which cranial nerves are sensory?
CNs 1, 2, and 3 (olfactory, optic, and oculomotor)
What does the olfactory nerve do?
it carries the sense of smell from the nasal cavity to the cerebrum
What is cranial nerve 2 and what is it responsible for?
The optic nerve; responsible for eyesight
What is cranial nerve 3 and what is it responsible for?
The oculomotor nerve; responsible for moving the eye
What is cranial nerve 12 and what is it responsible for?
Hypoglossal nerve; innervates all the extrinsic and intrinsic muscles of the tongue except for palatoglossus muscle; involved in speech and swallowing too.
What are signs that the hypoglossal nerve is damaged?
tongue is deviated to the side of a lesion or is paralyzed; person cannot stick out their tongue.
Where does the hypoglossal nerve originate from?
the medulla oblongata
What is cranial nerve 10 and what is it responsble for?
Vagus; has sensory, parasympathetic, and motor functions
What is the sensory nerve function of the vagus nerve?
Innervates the skin of the external acoustic meatus and the internal surfaces of the laryngopharynx and larynx. Provides visceral sensation to the heart and abdominal viscera.
What is the special sensory nerve function of the vagus nerve?
provides taste to the epiglottis and the root of the tongue
What is the motor function of the vagus nerve?
Provides motor innervation to the majority of the muscles of the pharynx, soft palate and larynx.
What is the parasympathetic function of the vagus nerve?
Innervates the smooth muscle of the trachea, bronchi and gastro-intestinal tract and regulates heart rhythm.
Where does the vagus nerve originate?
in the medulla oblongata
What cranial nerves exit the cranium via jugular foramen?
vagus, glossopharyngeal (CN IX), and accesory (XI)
What is the auricular branch?
a branch of the vagus nerve found in the head; it provides sensation to the outside of the external auditory canal and the outside ear.
What is the pharyngeal branch?
A branch of the vagus nerve found in the neck; provides motor sensation to the muscles of the pharynx and soft palate
What is the superior laryngeal nerve?
A branch of the vagus nerve found in the neck that has an external and internal branch. The external part innervates the cricothyroid muscle and the internal part innervates the laryngopharynx and the superior (upper) part of the larynx
What is the recurrent laryngeal nerve?
A branch of the vagus nerve on the right side only; it innervates most of the intrinsic muscles of the larynx
What are the vagal trunks?
nerves in the thorax formed from the right and left sides of the vagus nerve; its branches form the esophageal plexus, which innervates the smooth muscle of the oesophagus
What is the left recurrent laryngeal nerve?
a branch of the vagus nerve located in the thorax; it innervates most of the intrinsic muscles of the larynx
What are cardiac branches?
branches of the vagus nerve found in the thorax; it lowers and regulates heart rate and provides visceral sensation to the heart.
Where does the vagus nerve end?
in the abdomen; the vagal trunks end there and they innervate the oesophagus, stomach, and small and large bowels.
