Head and Neck Anatomy Flashcards
What cranial nerve supplies the muscles of facial expression?
Facial nerve (the terminal 5 motor branches of the facial nerve)
Which pharyngeal arch do the muscles of facial expression come from?
2nd pharyngeal arch
What is the innervation of the buccinator muscle?
Facial – it is not a muscle of mastication (and therefore innervated by trigeminal nerve)
How does the facial nerve exit the skull base?
Internal acoustic meatus
How does the facial nerve exit the skull?
Stylomastoid foramen
What are the 5 terminal motor branches of the facial nerve?
Temporal, Zygomatic, Buccal, Marginal Mandibular + cervical
The facial nerve gives off a branch named ‘nerve to stapedius’ which innervates the stapedius muscle. What is the function of this muscle?
To contract and dampen down vibrations
The facial nerve is one of our four parasympathetic nerves. What structures does it innervate for it to be given this title?
Submandibular + Sublingual salivary glands + Lacrimal gland
How does the facial nerve innervate the tongue?
Special sensation to the anterior 2/3 via the chorda tympani branch
At what vertebral level does the hyoid bone lie?
C3
How many cervical spinal nerves do we have?
8 (and 7 vertebrae)
What is the innervation of the posterior belly of the digastric muscle?
Facial nerve
What is the innervation to the sternocleidomastoid muscle?
Accessory nerve (CNXI)
What is the function of the SCM muscle?
Bilateral contraction: Neck extension.
Unilateral contraction: Contralateral rotation + Ipsilateral neck flexion
What nerve roots create the ansa cervicalis?
Ventral rami of C1-C3
What structures lie within the carotid sheath?
- Common carotid artery
- Internal jugular vein
- Vagus nerve (CN X)
What are the borders of the anterior triangle of the neck?
Midline of the neck, anterior border of SCM, inferior surface of the mandible
What are the borders of the posterior triangle of the neck?
Posterior border of the SCM, anterior border of trapezius, middle third of the clavicle
What part of the thyroid gland connects to the two lobes?
Isthmus
What vertebral level does the thyroid span?
C4🡪 C7/T1
What is the blood supply to the thyroid gland?
Superior thyroid artery (from E. Carotid) + Inferior thyroid artery (from Thyrocervical trunk 🡪 from subclavian)
At what vertebral level does the common carotid bifurcate?
C4
If a patient presents with a midline neck lump that produces on tongue protrusion, what is the diagnosis?
Thyroglossal cyst
How do olfactory nerve fibres pass into the nasal cavity?
Through Cribiform plate of the ethmoid bone
What nerves deliver general sensation to the nasal cavity?
V1 (ophthalmic division) + V2 (maxillary division)
What sinuses drain via the middle meatus?
FAM – Frontal, Anterior ethmoid, Maxillary
Through which meatus does the posterior ethmoid sinus drain to get into the nasal cavity?
Superior meatus
Through which opening does the sphenoid sinus drain to get into the nasal cavity?
Sphenoethmoid recess (above superior turbinate)
The lacrimal gland drains via the nasolacrimal duct. Through which meatus will the nasolacrimal duct empty its secretions into the nasal cavity?
Inferior meatus
What is the medical term for a nosebleed?
Epistaxis
What type of epithelium lines the paranasal sinuses and bronchial tree?
Pseudostratified ciliated columnar epithelium
At what vertebral level does the cricoid cartilage lie?
C6
What is the only muscle to abduct (open) the vocal cords?
Posterior cricoarytenoid
The cricoid thyroid muscle tenses the vocal cords allowing an increase in pitch (often referred to as the singer’s muscle). What is the innervation of this muscle?
External branch of the superior laryngeal nerve
What is the anatomical name of the false vocal cords?
Vestibular folds
What is the function of the internal branch of the superior laryngeal nerve?
Sensory innervation of the mucosa above the vocal cords
Why do we need to adduct (close) the vocal cords?
Phonation
How can we differentiate between the true and false vocal cords?
True vocal cords lie below the false and are responsible for sound production (unlike the false cords which serve a protective function)
What muscle lies on the posterior aspect of the trachea functioning to expel a foreign body if it ends up in the trachea?
Trachealis
Which structure does the right recurrent laryngeal nerve loop underneath on its way up to the larynx?
Right Subclavian artery
Which structure does the left recurrent laryngeal nerve loop underneath on its way up to the larynx?
Arch of aorta
What is the sensory and motor innervation of the recurrent laryngeal?
Sensory: Mucosa below the vocal cords. Motor: All muscles other than cricothyroid
If a foreign body enters the respiratory tract which bronchi is it most likely to become lodged in?
Right main bronchus – it is more vertical + wider (and shorter)
What two additional features is the left lung going to have?
Cardiac notch + lingula
How many lobes in the right lung?
3 (divided by two fissures – horizontal + oblique)
What is the relationship of the Vagus and Phrenic nerves to the hilum?
Phrenic nerve travels anterior to the hilum. Vagus nerve travels posterior to the hilum
The pleura surround the root/hilum of the lung is going to continue inferiorly as what structure?
The Pulmonary ligament
Where does the apex of the lung project?
Above the first rib
What nerves pass through the superior orbital fissure?
Cranial Nerve 3, 4, 5(1), 6
How does the maxillary division of trigeminal get out of the skull?
Foramen rotundum
How does the mandibular division of the trigeminal get out of the skull?
Foramen ovale
What passes through the foramen spinosum?
Middle meningeal artery
The middle meningeal artery passes behind which structure?
Pterion
Rupture of the middle meningeal artery causes what type of haemorrhage?
Extradural haemorrhage
What structures pass out the skull through the stylomastoid foramen?
Facial nerve
Where is the anterior fontanelle located in infants?
Bregma (where sagittal suture meets coronal anteriorly)
Where is the posterior fontanelle located in infants?
Lambda – where the sagittal suture meets the lambdoid suture
What nerves pass out through the internal acoustic meatus?
7 (Facial) and 8 (Glossopharyngeal). Acoustic – needs to have something to do with the auditory pathway
What is the only cranial nerve to leave then re-enter the skull – describe its path?
Spinal accessory nerve (CNII). Nerve originates from the spinal cord between C1-C5 and runs superiorly to enter the cranial cavity through the foramen magnum. It then exists the skull through the jugular foramen
What is the name of the division between the two hemispheres of the brain?
Longitudinal fissure
What is the name of the division between frontal and parietal lobe?
Central sulcus
What is the name of the division between the temporal and frontal/parietal above it?
Sylvian fissure/lateral sulcus
What is the function of the pre-central gyrus?
Primary motor cortex
What parts of the homunculus would you find on the medial surface of the brain?
Lower limb and genitalia
What artery supplies the medial surface of the brain?
Anterior cerebral artery
What artery supplies the lateral surface of the brain?
Middle cerebral artery
Where would you find Broca’s area?
Inferior frontal lobe
What is the function of Broca’s area?
Motor aspect of speech
What would you see in a Broca’s aphasia?
Inability to make the motor movements needed for speech. Slurring making sounds that are incomprehensible.
What would you see in a Wernicke’s aphasia?
Can make sounds that can be made out as ‘words’ but the understanding is gone. They reply with responses that make no sense.
Where would you find Wernicke’s area?
Superior temporal lobe
What is the name of the connection between Wernicke’s and Broca’s?
Arcuate fasciculus
What structure lies close to the optic chiasm?
Pituitary gland
What type of visual loss would you therefore get with a pituitary adenoma?
Bitemporal hemianopia
What structures connect the two hemispheres of the brain?
Corpus callosum
What is the superior colliculus responsible for?
Integrating visual eye movements (sends information to lateral geniculate nucleus)
What is the function of inferior colliculus?
Involved in the auditory pathway
What skull foramina does the olfactory nerve pass through to get to the nasal cavity?
Cribriform plate of the ethmoid bone
What does the optic nerve pass through?
Optic canal
What nerves do the afferent and efferent limb of the direct and consensual light reflex?
Afferent – optic Efferent – Oculomotor
If a patient has a positive RAPD (relative afferent pupillary defect) – where could the issue be?
Optic nerve + retina
How many of the 7 extra-ocular muscles does the oculomotor nerve innervate?
5
What innervates the lateral rectus?
Abducens
What innervates the superior oblique?
Trochlear nerve
Where would you ask the patient to look to test the superior oblique?
Down and in
What would a patient with an oculomotor nerve lesion look like?
- Ptosis 2. Pupil looking down and out 3. Mydriasis (dilated pupil)
What is the function of the trigeminal (include both sensory and motor)?
Sensory – sensory. Motor: Muscles of mastication (specifically V3 – mandibular division of trigeminal)
What is the afferent and efferent limb of the corneal reflex?
Afferent: V1 (ophthalmic branch of trigeminal) Efferent: Facial
How does the maxillary division of trigeminal get out of the skull?
Foramen rotundum
How does the mandibular division of the trigeminal get out of the skull?
Foramen ovale
What does the facial nerve do?
Muscles of facial expression
What innervates the motor movements of the tongue?
Hypoglossal
In a right sided hypoglossal nerve lesion which side will the tongue be deviated towards?
Right side
How does the facial nerve exit the skull?
Stylomastoid foramen
What innervates the posterior 1/3 of the tongue (both general and special sensation)?
Glossopharyngeal
What innervates the special sensation to the anterior 2/3 of the tongue?
Chorda tympani branch of facial
What innervates the general sensation to the anterior 2/3 of the tongue?
Lingual branch of the trigeminal
At what vertebral level does the spinal cord end?
L1
What do we call the above site where the spinal cord ends?
Conus Medullaris
What landmark do we use to avoid the spinal cord when doing a lumbar puncture?
Iliac crest (highest point is at L4)
Where does CSF lie?
Subarachnoid space
What nerve fibres run within the ventral nerve root?
Motor nerves only
What nerve fibres run within the ventral and dorsal rami?
Motor AND sensory
What type of sensory information is carried by the dorsal column?
Proprioception, fine (discriminative) touch + vibration
Which limb of the internal capsule do the corticospinal tract fibres travel in?
Posterior limb
Through which portions of the brainstem do the corticospinal tract fibres travel in?
Crus cerebri (of midbrain), Basilar pons, Pyramids of medulla (motor tract travelling in the anterior aspect of the brainstem as motor is always anterior)
What happens to the remaining 10% of the corticospinal tract fibres that do not decussate?
Remain anterior as the anterior corticospinal tract (supplies the axial musculature)
What type of sensory information is carried by the spinothalamic tract?
Pain, temperature + crude touch (in anterior)
At what point does the spinothalamic tract decussate?
At the point at entry in the spinal cord.
At what point does the dorsal column and corticospinal tract decussate?
Thalamus
Fibres from the lower half of the body below T6 will ascend in which part of the dorsal column?
Gracile fasciculus (above T6 – cuneate fasciculus)
What is the function of the dural venous sinuses?
Drain the head and neck into the internal jugular vein
Why do we call it with dural venous sinuses?
Dural venous sinuses because the sinuses run within the two layers of the dura (endosteal and meningeal layers)
How does the CSF drain back into the venous circulation?
Arachnoid granulations
What two blood vessels come up to create the circle of Willis?
Vertebral artery and internal carotid
What does the internal carotid artery become (going to supply the convexity of the brain)?
Middle cerebral artery
What does the basilar artery supply?
Brainstem
An anterior cerebral artery stroke is going to cause disproportionate weakness in which part of the body?
Lower limbs
What are the two main types of stroke?
Ischaemic (85%) and haemorrhagic
Why can the corticospinal tract also be called the pyramidal tract?
Because the corticospinal tracts run through the pyramids (which sit anterior and remember the motor tracts run anterior) of the medulla.
Which part of the basal ganglia is affected in Parkinson’s disease?
Substantia nigra
Through which part of the internal capsule do they motor tracts run?
Posterior limb of the internal capsule (no motor fibres run in the anterior limb)
What cells secrete CSF?
Ependymal cells of the choroid plexus
What part of the ventricular system connects lateral ventricle to the third ventricle?
Interventricular foramen (Foramen of Monroe)
What part of the ventricular system connects the third to the fourth ventricle?
Cerebral aqueduct
What structures connect the 4th ventricle to the central canal?
Foramen of Lushke and Foramen of Magendie
What is the name of the nerve that emerges in between the posterior cerebral artery and the superior cerebellar artery?
Oculomotor nerve
What 3 structures (nuclei) make up the corpus striatum?
Caudate nucleus, putamen, and globus pallidus
What term do we use when referring to the caudate nucleus and the putamen?
Striatum
