Week 1 - head and neck (skull, dental, neck triangles) Flashcards
What are the characteristic features of cervical vertebrae?
Triangular vertebral foramen
Bifid spinous process
Transverse foramina
Between which bones does the nodding ‘yes’ movement occur?
Between atlas and the occiput
Between which bones does the shaking of the head ‘no’ movement occur?
Between atlas and axis
What are the articular surfaces of the atlanto-occipital joint?
occipital condyles and superior articular facets of atlas
Which movements occur at the atlanto-occipital joint?
Flexion, extension, a small amount of lateral flexion
Which movements occur at the atlanto-axial joint?
Axial rotation
Limited flexion, extension, lateral flexion
Which ligament wraps around the odontoid peg to enable axial rotation?
The transverse ligament of atlas
What are the unusual features of atlas?
No vertebral body, no spinous processes
What is the neurocranium?
The 8 bones that surround and protect the brain
What is the viscerocranium?
The 14 bones that make up the face
Which bones make up the neurocranium?
(mneumonic STEP OF) Frontal, sphenoid, ethmoid, occipital, temporal x2, parietal x2.
Which bones make up the viscerocranium?
Mandible, vomer, nasal bones x2, lacrimal bones x2, zygomatic bones x2, inferior nasal conchae x2, palatine bones x2, maxillae x2
Where is the lacrimal bone?
The infero-medial aspect of the orbit
The infra-orbital canal lies within which bone?
The maxilla - one canal each side of the nose
What travels in the infra-orbital canal?
The infraorbital nerve - a branch of the maxillary division of the trigeminal nerve
What travels through the mental canal?
The mental nerve, terminal branch of inferior alveolar nerve (from trigeminal), mental artery
Where is the mental canal?
In the mandible, one on each side, usually adjacent to the root of the mandibular second premolar tooth
Where is the squamous suture?
Between the parietal and temporal bones
Where is the coronal suture?
Between the frontal and parietal bones
Where is the lambdoid suture?
Between the parietal and occipital bone
Within which bone does the external acoustic meatus lie?
Temporal bone
Where is the mastoid process?
Inferior prominence of the temporal bone, just posterior to the ear
Where is the styloid process of the temporal bone?
inferomedial and anterior to the ear
Where is the incisive foramen of the maxilla?
centrally, anterior aspect of the roof of the mouth, just behind the two front teeth
What goes through the incisive foramen/ nasopalatine canal?
Greater palatine artery and vein, nasopalatine nerve (from maxillary)
What is the zygomatic arch?
The cheek bone, a thin arch of maxillary and temporal bone
What is the crista galli?
A thick midline, smooth triangular process from the superior surface of the ethmoid bone
What is the purpose of the crista galli?
To separate the olfactory bulbs, anterior attachment for the falx cerebri
What are the parts of the sphenoid bone?
Lesser wing, greater wing, sella turcica, medial and lateral pterygoid plate
Where is the vomer?
In the midline of the nasal cavity, forms the posterior-inferior part of the nasal septum
Which bones does the vomer articulate with?
Palatine, maxilla, ethmoid, sphenoid
What nerve goes through the cribriform plate?
The olfactory nerve (CNI)
What goes through the optic canal?
Optic nerve (CNII), ophthalmic artery, dural sheath of optic nerve
What goes through the Superior Orbital Fissure?
Oculomotor nerve (CNIII), Trochlear nerve (CNIV), Ophthalmic nerve (CNV1), Abducens nerve (CNVI), ophthalmic veins
What goes through the foramen rotundum?
Maxillary nerve (CNV2)
What goes through the foramen ovale?
Mandibular nerve (CNV3), acessory meningeal branch of maxillary artery, emissary vein (lesser petrosal nerve)
What nerves go through the internal acoustic meatus?
Facial nerve (CNVII), Vestibulocochlear nerve (CNVIII)
What goes through the Jugular foramen?
Glossopharyngeal nerve (CNIX), Vagus (CNX), descending portion of Accessory nerve (CNXI), internal jugular vein
What nerve goes through the hypoglossal canal?
Hypoglossal nerve (CNXII)
What goes through the foramen caecum?
Emissary veins
What goes through the foramen spinosum?
Middle meningeal artery
What goes through the foramen lacerum?
The Greater petrosal nerve - but it is mostly covered by connective tissue
What goes through the carotid canal?
Internal carotid artery
What goes through the foramen magnum?
Brainstem/spinal cord, vertebral arteries, ascending portion of spinal accessory nerve (CNXI)
What is the condylar process of the mandible?
The posterior superior aspect of the mandible, forms the TMJ
Where is the coronoid process of the mandible?
A bony projection on the anterosuperior aspect of the mandible
Where is the mandibular foramen?
On the medial surface of the ramus of the mandible - one on each side
Where are the mental foramen?
On the superficial surface of the body of the mandible, lateral to the midline - one on each side
Where is the mental protuberance?
On the superficial inferior aspect of the midline of the mandible
where is the mental tubercle?
One on each side, protrusions on the body of the mandible, either side of the mental protuberance
What are the four main parts of the mandible?
Ramus, Angle, Body, Aveolar part
What movements can occur at the temporomandibular joint?
Protrusion/retraction, lateral deviation, elevation and depression
Why is the TMJ considered an atypical joint?
Articular surfaces are lined with fibrocartilage rather than hyaline cartilage
What are the articular surfaces that make up the TMJ?
Temporal bone: mandibular fossa and articular tubercle
Mandible: condylar process
Which ligaments are involved in the TMJ?
Lateral temporomandibular ligament, (stylomandibular ligament, sphenomandibular liigament)
Which muscles elevate the jaw?
Temporalis, masseter, medial pterygoid muscles
Which muscles depress the jaw?
Lateral pterygoid, digastric, geniohyoid and mylohyoid muscles
Which muscles protrude the jaw?
Lateral pterygoid, medial pterygoid, masseter
Which muscles retract the jaw?
Posterior fibres of temporalis, deep part of masseter
Which muscles are involved in lateral deviation of the jaw?
Posterior fibres of temporalis, digastric, mylohyoid, geniohyoid (ipsilateral movement)
Lateral and medial pterygoids (contralateral movement)
What are the two divisions of the oral cavity?
Vestibule and oral cavity proper
What is the vestibule in the mouth?
The space between the teeth and the inner mucosal lining of the lips and cheeks
How many teeth do human adults have?
32
How many of each type of tooth is there?
8 incisors
4 canines
8 premolars
12 molars
What are the 9 surfaces of a tooth?
Incisal, occlusal, mesial, distal, buccal, palatal, lingual, labial, cervical
What is the incisal surface of a tooth?
The biting edge of the incisors and canines
What is the occlusal surface of a tooth?
The biting surface of premolars and molars
What is the mesial surface of a tooth?
The surface of any tooth nearest the mid-line of the arch
What is the distal surface of a tooth?
The surface of any tooth furthest from the midline of the arch
What is the buccal surface of a tooth?
The surface facing the cheeks (molars and premolars)
What is the palatal surface of a tooth?
The surface facing the palate of all upper teeth
What is the lingual surface of a tooth?
The surface facing the tongue in all lower teeth
What is the labial surface of a tooth?
The surface facing the lips (Incisors and canines)
What is the cervical surface of a tooth?
The part of the tooth next to the gingival margin
What are the layers of a tooth from superficial to deep?
Enamel, dentin, pulp chamber (blood vessels and nerves)
What is cementum?
The calcified substance covering the root of a tooth - a kind of continuation of the enamel layer
What are the functions of each type of tooth?
Incisor and canines: biting pieces of food
Premolar: tearing and grinding food
Molar: chewing and grinding food
What are the distinguishing features of incisors?
Chisel-shaped sharp edge, one root. distal occlusal surface more rounded than the mesial. Upper incisors are wider than lower incisors.
What are the distinguishing features of canines?
More pointed and slightly larger than incisors, one root. Upper canines are broad relative to their height, lower canines are narrow. The mesial occlusal ridge is usually shorter than the distal occlusal ridge.
What are the distinguishing features of premolars?
2 cusps, 1 or 2 roots. Upper: oval occlusal outline, two cusps of equal size. Lower: round occlusal outline, buccal cusp larger than lingual cusp. Long aspect of roots angle distally.
What are the distinguishing features of molars?
4 or 5 cusps, 2 roots (lower) 3 roots (upper). Upper: 3-4 major cusps and a rhombus-shaped outline. lower: 4-5 major cusps and a more square outline. all roots angle distally
What are the key features of deciduous teeth?
- Crowns with thinner enamel, whiter and more opaque
- More bulbous crowns
- thinner and shorter roots
- deciduous molars have divergent roots
- wider and more vascularised pulp chambers
What are the features of 3rd Molars?
Fused roots, less than 4 cusps, irregular shaped, smaller crowns
How are the teeth numbered?
Upper right 1 (1-8)
Upper left 2 (1-8)
Lower left 3 (1-8)
Lower right 4 (1-8)
What are the features of permanent teeth?
Larger, cervical necks are straighter and more in line with the roots
The pulpal chambers are smaller and the crowns are larger in proportion with the roots
Why are teeth good for aging people?
Even in people with delayed growth development, their teeth still develop at the same rate
What are the attachments of the platysma muscle?
O: Fascia/skin of infra and supraclavicular regions
I: Lower border or mandible, skin of cheek, lower lip, modiolus, obicularis oris muscle
What is the innervation to platysma?
Cervical branch of the facial nerve
What is the blood supply to platysma?
Submental artery (from facial), suprascapular artery
What are the actions of the platysma muscle?
Depresses mandible and angle of mouth, tenses skin of lower face and anterior neck
Which two veins come together to become the external jugular vein?
Posterior division of the retromandibular vein and the posterior auricular vein
What are the tributaries of the external jugular vein?
Cervical, suprascapular and anterior jugular veins
Which vein does the external jugular drain into?
Subclavian vein
What is the pathway of the external jugular vein?
From mandibular angle just below parotid gland, descends downwards deep to platysma, superficial to sternocleidomastoid, crosses the transverse cutaneous nerve and lies parallel with the great auricular nerve, crosses the deep cervical fascia and into subclavian
What are the four deep fascias of the neck?
Investing layer, pretracheal layer, prevertebral layer, carotid sheath
What is the investing layer?
The most superficial of the deep fascial layers, enclosing trapezius, sternoicleidomastoid, submandibular and parotid glands
What is the pretracheal layer?
The fascia around the trachea, oesophagus and other nearby structures
What is the prevertebral layer?
A fascia that encloses the vertebral column and deep neck muscles
What is contained within the carotid sheath?
Common carotid arteries, internal carotids, jugular vein, vagus nerve, deep cervical lymph nodes, carotid sinus, sympathetic fibres
What are the attachments of the sternocleidomastoid muscle?
O: Superior part of manubrium sternum and superior surface of the medial third of the clavicle
I: Lateral surface of mastoid process of the temporal bone and lateral part of superior nuchal line
What is the innervation to sternocleidomastoid?
Accessory nerve, branches of cervical plexus (C2-C3)
What are the functions of sternocleidomastoid?
Unilateral contraction: neck ipsilateral flexion, contralateral rotation
Bilateral contraction: neck flexion and extension, elevation of clavicle and sternum
What is Erb’s point?
The nerve point of the neck- where the cutaneous branches of the cervical plexus enter the skin (used when performing a cervical plexus nerve block)
Where is erbs point?
Halfway along the posterior border of sternocleidomastoid
What are the three occipital nerves and their supply?
Greater occipital nerve: Skin of the posterior scalp to the coronal suture, skin overlying parotid gland
Lesser occipital nerve: Lateral scalp, skin around external ear
Third occipital nerve: zygapophyseal joint, semispinalis muscle, skin of nuchal area
What does the greater auricular nerve supply?
Skin of the auricle, skin over the parotid gland and mastoid process
(From cervical plexus - C2,3)
What does the transverse cervical nerve supply?
The skin of the anterolateral cervical region
(from cervical plexus, C2,3)
What do the supraclavicular nerves supply?
The skin over the shoulder, from C3,4
What are the borders of the anterior triangle of the neck?
Apex: suprasternal notch. Base: inferior margin of the mandible. Anterior border: midline of the neck. Posterior border: anterior margin of sternocleidomastoid
What are the borders of the posterior triangle of the neck?
Apex: posteroinferior to mastoid process. Base: Midline 1/3rd of clavicle. Anterior border: Posterior margin of sternocleidomastoid. Posterior border: Anterior margin of trapezius.
What are the subdivisions of the anterior triangle?
Muscular triangle, carotid triangle, submandibular triangle and submental triangle
Which muscles are contained within the anterior triangle?
Thyrohyoid, sternothyroid and sternohyoid muscles
Which organs are contained within the anterior triangle?
Thyroid gland, parathyroid gland, larynx, trachea, oesophagus, submandibular gland, some of parotid gland
Which arteries are contained within the anterior triangle?
Superior and inferior thyroid, common carotid, external carotid, internal carotid, facial, submental, lingual arteries
Which veins are contained within the anterior triangle?
Anterior jugular vein, internal jugular, common facial, lingual, superior and middle thyroid, facial, submental, lingual veins
Which nerves are contained within the anterior triangle of the neck?
Vagus nerve, hypoglossal nerve, part of sympathetic trunk, mylohyoid nerve
What are the borders of the muscular triangle?
Superior: hyoid bone. Lateral: superior belly of omohyoid and anterior border of sternocleidomastoid
Medial: midline of the neck
What are the contents of the muscular triangle?
Muscles: thyrohyoid, sternothyroid, sternohyoid
Vessels: superior and inferior thyroid arteries and anterior jugular veins
Viscera: thyroid gland, parathyroid gland, larynx, trachea, oesophagus
What are the borders of the carotid triangle?
Anterior: superior belly of omohyoid
Superior: stylohyoid and posterior belly of digastric
Posterior: anterior border of sternocleidomastoid
What are the contents of the carotid triangle?
Arteries: common carotid, external carotid, internal carotid
Veins: internal jugular, common facial, lingual, superior thyroid, middle thyroid
Nerves: vagus, hypoglossal, part of sympathetic trunk
What are the borders of the submandibular triangle?
Superior: inferior border of mandible
Lateral: anterior belly of digastric
Medial: posterior belly of digastric
What are the contents of the submandibular triangle?
Viscera: submandibular gland, lymph nodes, caudal part of parotid gland
Vessels: facial artery and vein, submental artery and vein, lingual artery and vein
Nerves: mylohyoid and hypoglossal
What are the borders of the submental triangle?
Inferior: hyoid bone
lateral: anterior belly of digastric
Medial: midline of neck
What are the contents of the submental triangle?
Anterior jugular vein and submental lymph nodes
What are the divisions of the posterior triangle?
Occipital triangle, supraclavicular triangle
What are the contents of the posterior triangle?
Vessels: subclavian, suprascapular and transverse cervical arteries, external jugular vein
Nerves: accessory nerve, trunks from brachial plexus, fibers of cervical plexus
Which are the suprahyoid muscles?
digastric, mylohyoid, geniohyoid and stylohyoid
Which are the infrahyoid muscles?
omohyoid, sternohyoid, sternothyroid and thyrohyoid
What are the attachments of digastric?
O: anterior belly: digastric fossa of mandible. posterior belly: mastoid notch of temporal bone
I: body of hyoid bone
What are the actions of digastric?
depresses mandible, elevates hyoid bone during chewing and swallowing
What is the innervation to digastric?
Anterior belly: mylohyoid nerve (CN V3)
Posterior belly: digastric branch of facial nerve (CN VII)
What are the attachments of mylohyoid?
O: Mylohyoid line of mandible
I: Mylohyoid raphe, body of hyoid bone
What are the actions of mylohyoid?
Forms floor of oral cavity, elevates hyoid bone and floor of mouth, depresses mandible
What is the innervation to the mylohyoid muscle?
Nerve to mylohyoid (from inferior alveolar nerve - CN V3)
What are the attachments of geniohyoid?
O: inferior mental spine
I: body of hyoid bone
What are the actions of geniohyoid?
Elevates and draws hyoid bone anteriorly, widens pharynx
What is the innervation to geniohyoid?
Anterior ramus of spinal nerve C1 - via hypoglossal nerve
What are the attachments of the stylohyoid muscle?
O: styloid process of temporal bone
I: body of hyoid bone
What are the actions of stylohyoid?
Elevates and draws hyoid bone posteriorly
What is the innervation of stylohyoid?
Stylohyoid branch of facial nerve (CN VII)
What are the attachments of omohyoid?
O: inferior belly: superior border of scapula. Superior belly: intermediate tendon
I: inferior belly: intermediate tendon. Superior belly: body of hyoid bone
What are the actions of omohyoid?
Depresses and retracts hyoid and larynx
Tenses carotid sheath
What is the innervation to omohyoid?
Anterior rami of spinal nerves C1-C3 (via ansa cervicalis)
What are the attachments of sternohyoid?
O: manubrium of sternum, medial end of clavicle
I: inferior border of hyoid bone
What is the action of sternohyoid?
Depresses hyoid bone
What is the innervation to sternohyoid?
Anterior rami of spinal nerves (C1-C3 - via ansa cervicalis)
What are the attachments of sternothyroid?
O: posterior surface of manubrium
I: oblique line of thyroid cartilage
What is the action of sternothyroid?
To depress the larynx
What is the innervation to sternothyroid?
Anterior rami of C1-C3 (Via ansa cervicalis)
What are the attachments of thyrohyoid?
O: Oblique line of thyroid cartilage
I: inferior border of body and greater horn of hyoid bone
What are the actions of thyrohyoid?
Depresses hyoid bone, elevates larynx
What is the innervation of thyrohyoid?
Anterior ramus of spinal nerve C1 via hypoglossal nerve
What are the three parts of the hyoid bone?
Body, lesser horns, greater horns
Where does the hyoid bone sit?
Just above the thyroid cartilage
What is the laryngeal prominence?
Adam’s apple - the midline of the thyroid cartilage
What type of cartilage is the thyroid cartilage made from?
Hyaline
Where are the vocal cords?
In the larynx at the level of the laryngeal prominence
What is the innervation to the vocal cords?
Vagus - recurrent and superior laryngeal nerves
What are the three paired cartilages of the throat?
arytenoid, corniculate and cuneiform
What are the three unpaired cartilages of the throat?
thyroid, cricoid, epiglottis
What is the thyrohyoid membrane?
A membranous sheet connecting the upper border of the thyroid cartilage with the hyoid bone
What is the structure of the cricoid cartilage?
It is a complete circle of cartilage, shaped like a signet ring with the signet part facing posteriorly
What is the path of the hypoglossal nerve through the submandibular triangle?
Passes deep to posterior belly of digastric and mylohyoid to enter the floor of the mouth
Where do the submandibular glands sit?
Under the floor of the mouth, posteriorly, open into the floor of the mouth, either side of the frenulum
What is the pathway of the accessory nerve through the neck?
Through jugular foramen, It passes anterolateral to the jugular vein, passes inferiorly, medial to stylohyoid and digastric, pierces sternocleidomastoid, travels along the posterior edge of SCM, then travels posteriorly and inferiorly along trapezius
How are the nerves of the cervical plexus related to the hypoglossal nerve?
motor efferents and sensory afferents from the cervical plexus join on to the hypoglossal nerve and basically hitch a ride to reach other muscles
What is the pathway of the hypoglossal nerve?
starts medially, travels laterally and inferiorly across the greater horn of the hyoid bone
Which nerve runs alongside the hypoglossal nerve in the neck?
Nerve to thyrohyoid muscle (C1)
What are the nerve roots of the cervical plexus?
Anterior C1-C4
What are the sensory branches of the cervical plexus?
Lesser Occipital nerve, Greater Auricular nerve, Transverse cervical nerve, Supraclavicular nerve (Lets go to sleep)
What are the motor branches of the cervical plexus?
Muscular branches to (sternocleidomastoid, prevertebral, levator scapulae), ansa cervicalis and Phrenic nerve (MAP)
What does the ansa cervicalis nerve do?
Motor supply to the infrahyoid muscles
What are the 5 divisions of the ansa cervicalis nerve?
(Susan Saw Game Of Thrones) Sternohyoid nerve, sternothyroid nerve, geniohyoid nerve, omohyoid nerve, thyrohyoid nerve
Which two nerves are carried by the hypoglossal nerve?
geniohyoid and thyrohyoid
Which nerve is the superior laryngeal nerve a branch of?
The vagus nerve
What are the two branches of the superior laryngeal nerve and what do they supply?
External laryngeal (supplies cricothyroid muscle) and internal laryngeal (mucosal sensation to supraglottis, epiglottis and taste to the valleculae
What does the facial vein drain into?
Internal Jugular vein
Where does the facial vein drain?
Face, lips, submandibular and thyroid gland
Which vein does the superior and middle thyroid vein drain into?
The internal jugular vein (some say superior drains into external jugular)
At what level do the carotids bifurcate?
C4
What are the branches of the external carotid artery?
Superior thyroid, ascending pharyngeal, lingual, facial, occipital, posterior auricular, maxillary, superficial temporal artery (some anatomists like freaking out poor medical students)
What does the superior thyroid artery supply?
Thyroid gland, infrahyoid muscles, sternocleidomastoid muscle
What does the ascending pharyngeal artery supply?
Pharynx, prevertebral muscles, middle ear, cranial meninges
What does the lingual artery supply?
Intrinsic muscles of the tongue, floor of the mouth
What does the facial artery supply?
Tonsils, palate, submandibular glands
What does the posterior auricular artery supply?
Parotid gland, facial nerve, ear, scalp
What does the maxillary artery supply?
External acoustic meatus, tympanic membrane, dura mater, calvaria, mandible, gingivae, teeth; temporal, pterygoid, masseter, buccinator muscles
What is in the carotid sinus?
Baroreceptors - innervated by pharyngeal and vagus nerves (at base of internal carotid)
What is in the carotid body?
A mass of nerve tissue containing chemoreceptors - innervated by glossopharyngeal and vagus nerves (at bifurcation of common carotids)
At which vertebral level does the thyroid gland sit?
C5-T1
What is the structure of the thyroid gland?
Two lobes with an isthmus connecting, sometimes with a pyramidal lobe extending superiorly from the isthmus
What is the structure of the thyroid gland?
Two lobes with an isthmus connecting, sometimes with a pyramidal lobe extending superiorly from the isthmus
What does the recurrent laryngeal nerve do?
motor to all intrinsic muscles of larynx except cricothyroid
Sensory to laryngeal mucosa below vocal cords
Where do the parathyroid glands sit?
Attached to the posterior surface of the thyroid gland lobes, 1-3 on each side
What are the attachments of splenius capitis?
O: spinous processes of vertebrae C7-T3, nuchal ligament
I: Lateral superior nuchal line of occipital bone, mastoid process of temporal bone
What are the actions of splenius capitis?
Bilateral contraction: extends head/neck
Unilateral contraction: ipsilateral flexion and rotation of the head
What is the innervation to splenius capitis?
Posterior rami of spinal nerves C2-C3
What are the attachments of levator scapulae?
O: transverse processes of vertebrae C1-C4
I: Medial border of scapula
What is the innervation of levator scapulae?
Dorsal scapula nerve, anterior rami of C3, C4
What are the actions of the scalenes?
neck flexion, ipsilateral lateral flexion, elevates rib 1 (anterior and middle), elevates rib 2 (posterior scalene)
What are the attachments of anterior scalene?
O: transverse processes of C3-C6
I: rib 1
What are the attachments of middle scalene?
O: transverse processes of ribs C2-C7
I: Rib 1
What are the attachments of posterior scalene?
O: transverse processes of C5-7
I: Rib 2
What is the innervation to the scalene muscles?
The anterior rami of the spinal nerves one below each of their attachments
Anterior: C4-C6
Middle: C3-C8
Posterior: C6-C8
Which structures pass between the middle and anterior scalene muscles?
Subclavian artery and roots of the brachial plexus
Which structures pass in front of the anterior scalene muscle?
Subclavian vein, transverse cervical artery and suprascapular artery
What is the innervation to the larynx?
Motor = recurrent laryngeal except cricothyroid which is external laryngeal
Sensory = internal laryngeal for glottis and above, recurrent laryngeal for below vocal cords
What goes through the petrotympanic fissure?
Chorda tympani and anterior tympanic artery
