Motor Cranial Nerves

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the origin of the hypoglossal nerve (XII)?

Caudal part of the groove bounding to pons

Rostral part of the groove bounding to pyramids of medulla oblongata

Caudal part of the groove bounding to pyramids of medulla oblongata (correct)

Rostral part of the groove bounding to cerebellum

What is the function of the hypoglossal nerve (XII)?

Supply the pharyngeal muscles

Supply the facial muscles

Supply 3 Intrinsic muscles of the tongue

Supply 3 Extrinsic muscles of the tongue (correct)

What is the origin of the trigeminal nerve (V)?

One root from the end of the cerebellum

Two roots from the end of the medulla oblongata

Two roots from the end of the pons (correct)

One root from the end of the spinal cord

What is the name of the ganglia associated with the trigeminal nerve (V)?

Semilunar ganglia Signup and view all the answers

What nerve emerges from the orbital foramen along with the ophthalmic nerve?

All of the above Signup and view all the answers

What is the function of the lacrimal nerve?

Supply the lacrimal gland and upper eyelid Signup and view all the answers

What is the name of the nerve that passes rostrally under the dorsal rectus muscle?

Naso-ciliary nerve Signup and view all the answers

What nerve does the chorda tympani unite with to supply the cranial tongue with taste sensation?

Lingual nerve of mandibular Signup and view all the answers

What is the course of the maxillary nerve?

From the round foramen (rotundum foramen) Signup and view all the answers

Which nerve arises from the facial nerve and supplies the skin on the concave aspect of the external ear?

Internal auricular nerve Signup and view all the answers

What is the function of the parotid branches of the facial nerve?

Supply the guttural pouch and parotid salivary gland Signup and view all the answers

What is the origin of the glossopharyngeal nerve?

Lateral part of the ventral surface of the medulla oblongata Signup and view all the answers

What is the function of the tympanic nerve?

Is a branch of the glossopharyngeal nerve Signup and view all the answers

What is the course of the glossopharyngeal nerve?

From the foramen lacerum caudalis to the foramen magnum Signup and view all the answers

What is the function of the dorsal buccal branch of the facial nerve?

Supplies the dorsal aspect of the cheek Signup and view all the answers

What is the function of the ramus colli?

Supplies the ventral auricular muscles Signup and view all the answers

What is the main function of the superficial branch of the lingual nerve?

Supplying the sublingual salivary gland, floor of the mouth, and MM of the tongue Signup and view all the answers

What nerve connects with the beginning of the lingual nerve to supply the cranial 2/3 of the tongue with taste sensation?

Chorda tympani of the facial nerve Signup and view all the answers

What nerve arises from the mandibular nerve and supplies the mylohyoid muscle, skin of the mandibular space, and rostral belly of the digastric muscle?

Mandibular alveolar nerve Signup and view all the answers

What nerve supplies the caudal belly of the digastric muscle?

Digastric nerve Signup and view all the answers

What is the origin of the facial nerve?

Lateral end of the trapezoid body Signup and view all the answers

What nerve is larger and lateral to the facial nerve?

Vestibulocochlear nerve Signup and view all the answers

What is the function of the greater superficial petrosal nerve?

Carrying parasympathetic fibers to form the nerve of the pterygoid canal Signup and view all the answers

What is the function of the stapedial nerve?

Supplying the stapedial muscle of the middle ear Signup and view all the answers

Which cranial nerve is responsible for supplying the dorsal oblique muscle?

Trochlear nerve (IV) Signup and view all the answers

What is the clinical significance of a problem in the dorsal branch of the oculomotor nerve?

Dropping of the upper eyelid Signup and view all the answers

Through which foramen does the trochlear nerve exit?

Orbital foramen Signup and view all the answers

What is the origin of the abducent nerve (VI)?

Cranial part of the groove bounding the pyramids of the medulla oblongata Signup and view all the answers

What is the supply of the large ventral branch of the oculomotor nerve (III)?

Ventral rectus, ventral oblique, and medial rectus Signup and view all the answers

What is the reason why the accessory nerve is termed 'spinal accessory nerve'?

It has a medullary root and a spinal root Signup and view all the answers

Which muscle is supplied by the ventral branch of the accessory nerve (XI)?

Sternocephalic muscle Signup and view all the answers

What is the result of any problem in the nerves that supply the extrinsic muscles of the eye?

Any type of squint Signup and view all the answers

What is the function of the tympanic plexus?

To supply the muscles of the tympanic cavity and auditory tube Signup and view all the answers

Which nerve supplies the caudal stylopharyngeal muscle?

Glossopharyngeal nerve Signup and view all the answers

What is the origin of the vagus nerve?

Medulla oblongata Signup and view all the answers

What is the function of the pharyngeal branch of the vagus nerve?

To supply the muscles of the pharynx Signup and view all the answers

Which nerve is the largest cranial nerve?

Vagus nerve Signup and view all the answers

What is the function of the recurrent laryngeal nerve?

To supply the intrinsic muscles of the larynx Signup and view all the answers

What is the function of the cardiac plexus?

To supply the heart and great vessels Signup and view all the answers

What is the function of the lingual branch of the glossopharyngeal nerve?

To supply the caudal third of the tongue with general and taste sensation Signup and view all the answers

Study Notes

Oculomotor Nerve (III)
- Origin: middle of medial border of cerebral peduncle (crus)
- Course: exits from orbital foramen, divided into small dorsal and large ventral branches
- Supplies: dorsal rectus muscle, levator palpebral superioris, ventral rectus, ventral oblique, and medial rectus muscles
- Clinical significance: ptosis (dropping of upper eyelid) can result from problems in the dorsal branch of the oculomotor nerve or levator palpebral superioris
Trochlear Nerve (IV)
- Origin: rostral cellular peduncle
- Course: exits from trochlear foramen (if present) or orbital foramen
- Supplies: dorsal oblique muscle
Abducent Nerve (VI)
- Origin: cranial part of the groove bounding to pyramids of medulla oblongata
- Course: exits from orbital foramen
- Supplies: lateral rectus and retractor oculi muscles
- Clinical significance: problems in the nerves that supply extrinsic eye muscles can cause squint (any type of strabismus)
Accessory or Spinal Accessory Nerve (XI)
- Origin: lateral part of ventral aspect of medulla oblongata
- Course: exits from foramen lacerum caudalis and branches into dorsal and ventral branches
- Supplies: trapezius and brachiocephalic muscles
- Note: termed spinal accessory nerve because its origin not only from medulla oblongata (medullary root) but also from 1st, 2nd, and 3rd cervical spinal nerves
Hypoglossal Nerve (XII)
- Origin: caudal part of the groove bounding to pyramids of medulla oblongata
- Course: exits from hypoglossal foramen
- Supplies: 3 extrinsic tongue muscles (styloglossus, hyoglossus, and genioglossus)

Mixed Cranial Nerves

Trigeminal Nerve (V)
- Origin: two roots (large sensory and small motor root) from the end of the pons
- Course: exits from orbital foramen
- Supplies:
  - Ophthalmic nerve (pure sensory): supplies lacrimal gland and upper eyelid
  - Maxillary nerve (pure sensory): supplies skin of face
  - Mandibular nerve (mixed): supplies muscles of mastication and skin of face
- Clinical significance: problems in the trigeminal nerve can cause facial pain and disorders of mastication
Facial Nerve (VII)
- Origin: lateral end of the trapezoid body
- Course: enters internal acoustic meatus and passes in facial canal
- Supplies:
  - Greater superficial petrosal nerve: carries parasympathetic fibers to the lacrimal gland
  - Chorda tympani: carries taste sensation from the anterior two-thirds of the tongue
  - Stapedial nerve: supplies stapedial muscle of the middle ear
- Clinical significance: problems in the facial nerve can cause facial paralysis and disorders of taste and hearing
Glossopharyngeal Nerve (IX)
- Origin: lateral part of ventral surface of medulla oblongata
- Course: exits from foramen lacerum caudalis (jugular foramen)
- Supplies:
  - Tympanic nerve: supplies the middle ear
  - Carotid sinus branch: forms carotid plexus with sympathetic fibers
  - Lingual branch: supplies the caudal one-third of the tongue with general and taste sensations
Vagus Nerve (X)
- Origin: lateral part of ventral surface of medulla oblongata
- Course: exits from foramen lacerum caudalis (jugular foramen)
- Supplies:
  - Pharyngeal branch: forms pharyngeal plexus with sympathetic fibers
  - Cranial laryngeal nerve: supplies the larynx and floor of the pharynx
  - Recurrent laryngeal nerve: supplies the intrinsic laryngeal muscles except for the cricothyroid muscle
- Clinical significance: problems in the vagus nerve can cause disorders of swallowing, speech, and heart rate

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz covers the origin, course, and branches of the oculomotor nerve, including its clinical significance in relation to ptosis.

Motor Cranial Nerves - Oculomotor Nerve (III)

Choose a study mode