Cranial Nerves + Tongue Muscles And HYPOGLOSSAL NERVE (XII) Flashcards
Origin of the muscles of the tongue
Occipital somites
Origin of the extrinsic muscles of the eye
Preotic somitomeres
Origin of the skeletal muscle associated to PAs
Non-segmented paraaxial mesoderm (somitomeres)
1st PA gives rise to … of the tongue
The body
3rd PA gives rise to … of the tongue
The root
Extrinsic muscles of the tongue
Genioglossus muscle, palatoglossus muscle, styloglossus muscle, hyoglossus muscle.
Which associated muscle of the tongue is this one?
Geniohyoid muscle
Intrinsic muscles of the tongue
Superior longitudinal, vertical, transverse, inferior longitudinal
hyoglossus, styloglossus, genioglossus, and all intrinsic muscles of the tongue are innervated by the … cranial nerve
XII-HYPOGLOSSAL (SE)
The palatoglossus is innervated by the pharyngeal plexus of the… nerve
VAGUS (X)
Anatomical relationships hypoglossal nerve
Superior to external carotid artery, inferior to stylohyoid and digastric muscles, superior to hyoglossus, deep to the mylohyoid.
Sensory afferent of the anterior 2/3 of the tongue
TRIGEMINAL NERVE (LINGUAL)
Sensory afferent of the posterior 1/3 of the tongue
GLOSSOPHARYNGEAL NERVE
Special afferent of the anterior 2/3 of the tongue
VII (CHORDA TYMPANI)
Special afferent of the posterior 1/3 of the tongue
GLOSSOPHARYNGEAL NERVE
A patient who shows weakness of tongue muscles, in which the tongue deviates towards the lesion sides might have suffered problems in the … nerve
HYPOGLOSSAL (XII)
(Prone to injury during cervical surgeries or carotid surgeries).
The hypoglossal nerve carries … fibers that innervate the geniohyoid and the thyrohyoid muscles.
C1
What does the OLFACTORY NERVE (I) innervate? What type of fibers does it carry?
The olfactory epithelium with SPECIAL AFFERENT, it is responsible for smell.
What type of neurons do we find in the OLFACTORY NERVE (I)?
Bipolar neurons (SPECIAL AFFERENT).
The central process connects to the OLFACTORY BULB, while the peripheral process connects to the OLFACTORY EPITHELIUM.
What kind of fibers does the OPTIC NERVE (II) carry?
SPECIAL AFFERENT with multipolar neurons, it innervates the eye.
They go from the DIENCEPHALON to the LENS PLACODE and the OPTIC CUP (future retina).
From where do the OCULOMOTOR NERVE (III) fibers come?
From the MIDBRAIN.
What type of fibers does the OCULOMOTOR NERVE (III) carry and what do they innervate?
- SOMATIC EFFERENT: extrinsic muscles of the eye.
- VISCERAL EFFERENT: ciliary and constrictor muscles (CILIARY GANGLION).
Where does the TROCHLEAR NERVE (IV) originate?
In the MIDBRAIN
What does the TROCHLEAR NERVE (IV) innervate and what kind of fibers does it carry?
It innervates the extrinsic muscles of the eye (músculo oblicuo superior) and it carries SE.
Where does the ABDUCENS NERVE (VI) originate?
Neuron’s bodies originate from the PONS
What type of fibers does the ABDUCENS (VI) carry and what does it innervate?
It carries SE and innervates extrinsic muscles of the eye (músculo recto lateral).
Where does the TRIGEMINAL NERVE (V) derive from?
From the Pons and the 1st PA.
What kind of fibers do we find in the TRIGEMINAL NERVE (V)?
- SOMATIC EFFERENT: masticator muscles.
- SENSORY AFFERENT: pseudounipolar neurons in TRIGEMINAL GANGLION. Central process goes to sensory area of Pons, while peripheral branches go to ORBITAL AND FNP REGION (NC V1), MAXILLARY AREA (NC V2), MANDIBULAR AREA (NC V3).
From where does the FACIAL NERVE (VII) come from?
From the Pons and the 2nd PA
What type of fibers does the FACIAL NERVE (VII) carry and what do they innervate?
- SOMATIC EFFERENT: mimic muscles
- VISCERAL EFFERENT: submaxillary gland and sublingual gland (SUBMANDIBULAR GANGLION), lacrimal gland (PTERYGOPALATINE GANGLION)
- SPECIAL VISCERAL AFFERENT: taste of the anterior 2/3 of the tongue (CHORDA TYMPANI).
What kind of fibers do we find in the VESTIBULOCOCHLEAR NERVE (VIII)?
- SPECIAL AFFERENT: bipolar neurons, central process goes to PONS and MEDULLA OBLONGATA and peripheral process goes to OTIC PLACODE.
….. nerve (position and equilibrium) joins the … nerve (acoustic input) to form the … nerve and enter the INTERNAL ACOUSTIC MEATUS
VESTIBULAR NERVE, COCHLEAR NERVE; VESTIBULOCOCHLEAR NERVE (VIII)
Where does the GLOSSOPHARYNGEAL NERVE (IX) derive from?
From the Medulla oblongata and the 3rd PA
What kind of fibers do we find in the GLOSSOPHARYNGEAL NERVE (IX)?
- SOMATIC EFFERENT: stylopharyngeus (deglutory muscle)
- VISCERAL EFFERENT: parotid gland (OTIC GANGLION)
- VISCERAL AFFERENT: peripheral processes go to carotid sinus and carotid body (mechano and chemoreceptors).
- SPECIAL VISCERAL AFFERENT: taste and sensitivity (BOTH!) of posterior 1/3 of tongue.
From where does the VAGUS NERVE (X) come?
From the medulla oblongata and the 4th (superior laryngeal nerve) and 6th (recurrent laryngeal nerve) PA.
What kind of fibers do we find in the VAGUS NERVE (X)?
- SOMATIC EFFERENT: deglutory muscles (4th PA - PALATOGLOSSUS MUSCLE) and phonatory muscles (6th PA).
- VISCERAL EFFERENT: muscles in the neck, thoracic and abdominal cavity.
- VISCERAL AFFERENT (pseudounipolar neurons): peripheral processes go to viscera of trunks and limbs.
- SPECIAL VISCERAL AFFERENT: taste in PHARYNX.
VA ganglion of Glossopharyngeal and Vagus nerves is located between entering the …. foramen.
JUGULAR
Where does the ACCESSORY NERVE (XI) originate?
At cervical level (in the spinal cord) and enters trough the FORAMEN MAGNUM. It then goes next to the VAGUS nerve and exits through the JUGULAR FORAMEN.
What kind of fibers do we find in the ACCESSORY NERVE (XI)?
- ONKY SOMATIC EFFERENTS: sternocleidomastoid and trapezius