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
Where does the HYPOGLOSSAL NERVE (XII) come from?
From the Medulla oblongata.
What kind of fibers does the HYPOGLOSSAL NERVE (XII) carry?
- ONLY SOMATIC EFFERENT: muscles of the tongue (HYOGLOSSUS, STYLOGLOSSUS, GENIOGLOSSUS, INTRINSIC MUSCLES TONGUE).
The tongue forms from the …. of PA 1 and 3.
MESENCHYME
What nerve carries PS fibers that innervate the constrictor muscle of the pupil?
OCULOMOTOR
What is the origin of the mucosa and connective tissue of the tongue?
the mesenchyme from the 1st and 3rd PAs
All cranial nerves originate from and/or end in the brain (T/F)
FALSE
The vagus nerve carries visceral and somatic motor fibers (T/F)
True
The vagus nerve innervates the derivatives of pharyngeal arches:
4th and 6th
What cranial nerves are accompanied along part of their trajectory by parasympathetic visceral efferents?
III, VII, IX, and X
Which cranial nerves innervate skeletal muscle derived from pharyngeal arches?
V, VII, IX, X
What cranial nerve carries fibers that innervate the parotid gland?
Glossopharyngeal
All cranial nerves exit/enter the cranial cavity via a cranial foramen or fissure (T/F)
True
Cranial nerves may carry sympathetic fibers along with other types of fibers (T/F)
False
Which cranial nerves do have special sensory afferent fibers?
I (OLFACTORY), II (OPTIC), VIII (VESTIBULOCOCHLEAR).
Which cranial nerves have special afferent visceral fibers?
VII (FACIAL), IX (GLOSSOPHARYNGEAL)
Which cranial nerves have bipolar neurons?
I (OLFACTORY), VIII (VESTIBULOCOCHLEAR)
Cranial nerves which control the extrinsic muscles of the eye.
III (OCULOMOTOR), IV (TROCHLEAR), VI (ABDUCENS)
Cranial nerve which controls the masticator muscles
V (TRIGEMINAL)
In the TRIGEMINAL GANGLION we can find … neurons
Pseudounipolar
(They will form the sensory afferent fibers)
Cranial nerve which derives from the 1st PA
Trigeminal
Cranial nerve that derives from the 2nd PA
Facial
Cranial nerve which controls mimic muscles
Facial
Submaxillary glands, sublingual gland and lacrimal gland are all innervated by the… nerve
Facial (VII)
The 3rd PA gives rise to the … nerve
GLOSSOPHARYNGEAL (IX)
The stylopharyngeus (deglutory muscle) is innervated by the … nerve.
GLOSSOPHARYNGEAL (IX)
Carotid body and carotid sinus are innervated by the … nerve.
GLOSSOPHARYNGEAL (IX)
(Visceral afferent fibers)
The palatoglossus muscle is innervated by the … nerve
VAGUS
The phonatory muscles are innervated by the … nerve
VAGUS
The Trigeminal and the vagus nerve both have afferent fibers with … neurons
Pseudounipolar
Muscles in neck, thoracic and abdominal cavities are innervated by the … nerve.
VAGUS (VISCERAL EFFERENT FIBERS)
Sternocleidomastoid and trapezius are innervated by the … nerve
ACCESSORY (SOMATIC EFFERENT FIBERS ONLY)
The muscles of the tongue originate from … but the tongue originates from …
OCCIPITAL SOMITES, THE MESENCHYME FROM 1ST AND 3RD PA
Cranial nerves which just have somatic efferent fibers
IV (TROCHLEAR), VI (ABDUCENS), XI (ACCESSORY), XII (HYPOGLOSSAL)
Cranial nerves which just have special sensory afferent fibers
OLFACTORY (I), OPTIC (II), VESTIBULOCOCHLEAR (VIII)
The skeletal muscles innervated by the hypoglossal nerve derives from… (pharyngeal arches/occipital somites).
OCCIPITAL SOMITES
Mucosa and CT of the tongue are derived from…
Mesenchyme of 1st and 3rd PA
Striate muscles that move the tongue are derived from…
Paraaxial mesoderm: SOMITES
In the centre of the terminal sulcus in the tongue, we find the ….
FORAMEN CAECUM
Functions of the tongue
Deglutition, phonation, taste
Extrinsic muscles of the tongue help in … functions
Deglutory
Intrinsic muscles of the tongue help in … functions
Phonation
Name these muscles of the tongue
- Palatoglossus
- Styloglossus
- Hyoglossus
- Genioglossus
The … originates in the mental spines and inserts in the hyoid bone and its tendon.
GENIOGLOSSUS
The … muscle originates at the styloid process and is responsible for bending the tongue (making a concave shape with it)
STYLOGLOSSUS
Muscle that extends from the hyoid bone. It elevates it for deglutition and despresses the root of the tongue.
HYOGLOSSUS
Muscle that originates at the soft palate and ends in the posterior aspect of the tongue. When it contracts, it blocks the passage between the oropharynx and oral cavity.
PALATOGLOSSUS
Name the following structure:
PALATOGLOSSAL ARCH
Palatoglossus is covered by oral mucosa, so in the oral cavity all we see is its impression on said mucosa: the PALATOGLOSSAL ARCH
Name the intrinsic muscles of the tongue
The geniohyoid is strictly a muscle of the tongue (T/F)
FALSE
It aids in performing deglutory functions as it elevates the hyoid bone. However, it is not a tongue muscle as it is not innervated by the hypoglossal (XII) nerve. It is innervated by the C1 branch.
The geniohyoid is innervated by the hypoglossal nerve (T/F)
False
It is innervated by the C1 branch.
TRAJECTORY HYPOGLOSSAL NERVE (XII)
It turns around the … artery, and the passes superficial to the …. artery. It then goes deep to the … muscle and …. muscle. It finally goes superficial to the … muscle.
OCCIPITAL, EXTERNAL CAROTID, STYLOHYOID, POSTERIOR BELLY OF THE DIGASTRIC, HYOGLOSSUS.
A branch of … incorporates to hypoglossal nerve and courses with it forming the Asa … This branch then detaches and innervates the geniohyoid and prethyroid musculature.
C1, CERICALIS
A distal lesion of the Hypoglossal nerve is done during neck surgery. Even though Hypoglossal nerve does not innervate them, could the Geniohyoid and thyroid musculature be affected?
Yes. C1 fibers which innervate those muscles course with the hypoglossal nerve in the distal region.
Lingual artery comes from…
External carotid artery
Lingual veins come from the…
Internal jugular vein
… nerve and … vein pass superficial to hyoglossus, however … artery and … vein pass deep to hyoglossus.
HYPOGLOSSAL AND DEEP LINGUAL, LINGUA AND DORSAL LINGUAL
If a patient has a lesion in the hypoglossal on one side. What would happen?
As the muscles are bilateral, there would be a partial paralysis of the tongue (hemiparalysis). The tongue will deviate towards the lesion side as the Genioglossus won’t be able to perform sticking out of the tongue.
A lesion to the recurrent laryngeal nerve would affect the cricothyroid joint?
No, as the cricothyroid muscle is the only muscle in the larynx innervated by the SUPERIOR LARYNGEAL NERVE (and not the recurrent).
Taste info from the beginning of the pharynx/any taste info past to the posterior 1/3 of the tongue is conveyed by the … nerve
VAGUS (X)