Anatomy H&N Flashcards
1
Q
Describe the the thyroid gland:
A
Function: Largest endocrine gland (also encompasses the histologicaly and functionally distant parathyroid), producing thyroid hormones (T3 & T4, metabolism) and calcitonin (Ca and PO4 homeostasis).
Appearance: Described as butterfly shaped due to two lobes either side of the midline of the neck, joined by an isthmus. There is often a pyramid of gland directed superiorly from the left or right lobe.
Position/Size: Spans C5-T1. Lies inferior to the thyroid cartilage and is encapsulated by a fibrous capsule which fuses the gland to the cricoid cartilage.
Capsule is enclosed in a loose sheath formed by the pretracheal layer of the deep cervical fascia.
Lies deep to sternothyroid and sternohyoid muscles
Right and left lobes anterolateral to the larynx and trachea
In close contact with the small parathyroid glands which are posterior.
2
Q
The fibrous thyroid capsule lies within?
A
The pre tracheal layer of the deep cervical fascia.
3
Q
Which is more superficial, the sternohyoid or sternothyroid muscle?
A
The sternothyroid is deeper as it attaches to the inferior edge of the thyroid cartilage, the sternohyoid passing over on its way caudal to the sternum.
4
Q
Microscopic description of the thyroid:
A
● Numerous lobules comprising individual follicles
● Supporting stroma and vasculature
● Follicles consists of single layer of cuboidal surface epithelium comprising thyroid follicular cells surrounding a central lumen containing colloid
● 10% of follicular epithelium contain parafollicular C cells, neural-crest derived containing granules of calcitonin
5
Q
What makes calcitonin? Where
A
Parafolicular C cells make up 10% of the surface cuboidal cells surrounding colloid.
6
Q
Follicular cells secrete? Stimulated by what and from where?
A
Follicular cells secrete thyroglobulin (contains iodine), T4 (storage and transport form), and T3 (active form)
Stimulated by TSH from anterior pituitary
7
Q
Relations of the thyroid gland:
A
Relations
● Anterolaterally: sternothyroid, sternohyoid, superior belly of omohyoid and SCM
● Posterolaterally: carotid sheath and contents: common carotid, IJV, vagus nerve
● Medially: larynx and trachea, pharynx and oesophagus, recurrent and superior laryngeal nerves
● Posteriorly: parathyroid glands, vertebral bodies
8
Q
Arterial supply to the thyroid
A
Arteries lie between the fibrous capsule and loose fascial sheath
1) Superior thyroid artery = anterior and superior
■ branch of external carotid
2) inferior thyroid artery = Posterior and inferior
■ branch of the thyrocervical trunk from 1st part of the subclavian artery
In 10% people isthmus is supplied by the Ima artery, a branch of brachiocephalic
9
Q
Venous drainage of the thyroid:
A
The 2 paired (superior and middle thyroid veins) and 1 unpaired (Inferior thyroid vein) form a venous plexus.
The Sup and middle drain to the IJV, the inferior to the brachiocephalic trunk.
10
Q
Any exam question about the lymphatic drainage of the thyroid should begin with:
A
Lymphatic vessels in the interlobar connective tissue and capsule.
11
Q
Lymphatic drainage of the thyroid:
A
Lymphatic vessels in the interlobar connective tissue and capsule are multidirectional complex and extensive. Drains initially into peri-thyroid nodes, somewhat ipsilaterally drain to: Pre laryngeal (midline so bilaterally to) -> superior deep cervical nodes Pre tracheal (midline so bilaterally to) -> inferior deep cervical nodes ***** Para tracheal (lateral so drain ipsilaterally) -> Inferior deep cervical nodes, supraclavicular nodes and upper mediastinal nodes
12
Q
Relations between structures in the carotid sheath:
A
IJV lateral to common carotid, vagus posteriorly.
Deep carotid nodes lie on the anterior lateral surface of the IJV.
13
Q
Course of the Right common carotid
A
Right: Branches from the bifurcation brachiocephalic trunk behind the sternoclavicular joint. Ascends in the neck along with the other structures in the carotid sheath until it bifurcates into external and internal branches at the SUPERIOR BORDER of the Thyroid cartilage where the External leaves the sheath on its more anterior course.
14
Q
Course of the Right common carotid
A
Left. Arises from the aortic arch immediately before the left subclavian artery, Travels 2cm superiorly in the superior mediastinum before entering the neck posterior to the Left sternoclavicular joint. Ascends in the neck along with the other structures in the carotid sheath until it bifurcates into external and internal branches at the SUPERIOR BORDER of the Thyroid cartilage where the External leaves the sheath on its more anterior course.
15
Q
Where does the external carotid artery begin and end?
A
Begins at the bifurcation of the common carotid at the superior border of the thyroid cartilage.
End when divides into terminal branches = maxillary artery and superficial temporal behind neck of mandible.
16
Q
Major Branches of the external carotid arteries:
A
1) (Almost immediately) Ascending laryngeal (gives off laryngeal branches)
2) Superior thyroid
3) Lingual
At the same level 4) & 5)
4) Facial artery, dips to medial side of angle of mandible to give off ascending palatine and tonsillar branches. Then rises superficial to the body turning superiorly to become the angular artery.
5) Occipital artery
6) Posterior auricular artery
The end at bifurcation into Terminal branches (post to neck of mandible:
Maxillary artery - to ptygopalantine fossa
Superficial temporal
17
Q
The internal carotid begins at what vertebral level? and can be divided into how many segments:
A more complex division:
A
Begins at C4. 4 segments: Cervical (continues in sheath w/o branches) Petrous Cavernous Cerebral
Bouthillier's divisions (surgical and radiological use) are in to 7. In the scheme above (no cerebral): Cervical Petrous ** Lacerum Cavernous ** Clinoid ** Ophthalmic ** Communicating
18
Q
Mnemonic for the internal carotid artery:
A
Conservative Politicians Love Compliant Cattle Over Complex arguments
Cervical Petrous Lacerum Cavernous Clinoid Ophthalmic Communicating artery.
19
Q
The cervical segment of the internal carotid ends at (what is anterior):
Describe the 1st part of common carotid
A
C1 ends at carotid canal posterior to JV
Bulges after origin (the carotid sinus/bulb)
20
Q
Course of cervical Internal carotid:
A
Ascends anterior to transverse processes of C1-3
Deep to parotid gland and internal jugular vein
Lateral to pharynx
Enters cranial cavity through carotid canal.
21
Q
At the base of the skull what lies between the jugular vein and the internal carotid?
A
At the base of the skull the glossopharyngeal, vagus, accessory, and hypoglossal nerves lie between the artery and the internal jugular vein.
22
Q
Describe C2 and C3 of the internal carotid:
A
Petrous (C2) Lacerum (C3)
○ Extends to foramen lacerum
○ Ascends in the carotid canal in petrous temporal bone
○ curves forwards and medially
○ then upwards and medially above foramen lacerum
○ Related posteriorly with cochlea and tympanic cavity
○ ***** superiorly with trigeminal ganglion
○ Surrounded by carotid plexus of nerves (sympathetic)
○ Branches: caroticotympanic and pterygoid
23
Q
Describe C4 and C5 of internal Carotid
A
Cavernous (C4) + Clinoid (C5) = Cavernous segment
Curves layers of the dura mater forming the cavernous sinus (covered by the lining membrane of the sinus):
- First ascends toward the posterior clinoid process,
- Then passes forward by the side of the body of the sphenoid bone,
- again curves upward on the medial side of the anterior clinoid process, and
- perforates the dura mater forming the roof of the sinus. The curve in the cavernous segment is called the carotid siphon.
This portion of the artery is medial to abducent nerve (VI)
The crinoid segment is a tiny little bit with no branches betten the cavernous sinus and where the artery enter sub-arachnoid space/
24
Q
Describe the ophthalmic segment of the internal carotid
A
○ After perforating dura medial to the anterior clinoid process
○ Curves backwards below optic nerve
○ Passes between optic and oculomotor nerves
○ Divides into anterior and middle cerebral arteries and join the Circle of Willis
○ Branches: ophthalmic, anterior cerebral, middle cerebral, posterior communicating, anterior choroid.
25
What does the external jugular vein do?
| Basic course:
Drains face and neck
Begins near angle of mandible from union of Posterior branch of the retromandibular vein, and posterior auricular vein.
Passes superficial to SCM where at inferior edge is joined by posterior external jugular vein.
Continues inferiorly. Right before is joins the SCV it is joined by the jugular venous arch.
26
The jugular venous arch arises from? Travels medially behind?
Gives off what big branch?
1st branch external jugular vein
Travels medially behind SCM and IJV
Gives of Anterior Jugular Vein
27
Mnemonics for branches of:
External Jugular vein
Internal Jugular vein
```
External Jugular:
PAST = Posterior, anterior Jugular, Suprascapular
Transverse Cervical (bifurcates into reteromandibular and post auricular)
```
Internal
Medical Schools Let Super Confident People In (ascending from middle thyroid)
28
Branches of the internal jugular vein (where does it begin?):
Begins in the posterior compartment of the jugular foramen, by the union of the inferior petrosal and sigmoid sinuses.
29
Origin of the jugular vein?
Begins at the base of skull in the posterior compartment of the jugular foramen, by the union of the inferior petrosal and sigmoid sinuses.
30
What is the venous angle?
Venous angle = site where the thoracic duct (L) and right lymphatic trunk (R) join the systemic circulation. Behind the medial end of the clavicle, where internal jugular unites with the subclavian vein to form the brachiocephalic vein.
31
Branches (inferior to superior) of the internal jugular vein
```
Formed by confluence of sigmoid sinus and inferior petrosal veins then:
1) Pharyngeal vein
2) Lingual vein
3) Common facial
4/5) sup and middle thyroid
6) Occipital vein
```
32
Course of the Subclavian vein:
● Begins at the lateral border of the first rib
● Continuation of the axillary vein
● Passes anterior to anterior scalene and phrenic nerve
● Unites with IJV at medial border of anterior scalene, posterior to medial end of clavicle to form the brachiocephalic vein.
33
What is the posterior relation to the phrenic nerve in the lower half of the neck?
The anterior scalene.
34
Course of the recurrent laryngeal nerve:
The left RLN is longer than the right, because it crosses under the arch of the aorta at the ligamentum arteriosum.
Typically ascend in a groove at the junction of the trachea and esophagus.
Pass behind the posterior, middle part of the outer lobes of the thyroid gland and enter the larynx underneath the inferior constrictor muscle,passing into the larynx just posterior to the cricothyroid joint.
The terminal branch is called the inferior laryngeal nerve.[
35
What forms the borders of the carotid triangle?
Posterior = SCM
Anterior: Superior body of omohyoidius
Superior: Posterior body of digastric
36
What runs within the carotid triangle (there are shitloads of things):
Bifurcation of common carotid, Carotid sheath with its contents (i.e vagus, nodes, IJV, internal carotid), external carotid and most of its branches (ascending pharyngeal, sup thyroid, lingual, facial, occipital.
Hypoglossal nerve, which crosses the bifurcated carotid arteries, and accessory nerve.
37
The internal carotid artery enters the skull base through the carotid canal, where it begins a series of 90° turns which lead it to eventually terminate as?
Describe the turns
The middle and anterior cerebral arteries.
5 Turns:
1) 90° anteromedially within the carotid canal to run through the petrous temporal bone.
2) 90° superiorly within the cavernous sinus
3) 90° turn anteriorly to travel along the roof of the cavernous sinus, where it grooves the body of the sphenoid.
Think of an "s" tipped to the left
4) 90° turn superiorly to exit posterior to the anterior clinoid
5) 90° turn inferior to run lateral to the chasm terminating in middle and anterior cerebral arteries.
38
Describe the larynx
● Anterior midline structure from levels C3-C6
● Fibrocartillagenous skeleton with muscles interiorly
● Divided into supraglottis, glottis and subglottis.
● Valve with the following functions:
i) An open valve in respiration
ii) Partially closed valve in phonation
iii) Closed valve to protect the airway during deglutition and coughing. A closed airway also allows a raised intra-abdominal pressure during defecation, micturition and parturition
39
What vertebral levels does the larynx span?
C3-C6
40
Relations of the Larynx:
Anterior: Skin, platysma, superior part of thyroid (this extend C5-T1)
Lateral: Piriform fossa, Sternohyoid (anterolateral), SCM,, carotid sheath and contents, recurrent laryngyneal nerves. Superior part of lateral lobes of thyroid
Posterior: Layngopahrynx (aka hypo pharynx)
Inferior: Continuous with cervical trachea
Superior: Superior border epiglottis, hyoid bone, hypo pharynx.
41
What subsections can the larynx be divided into?
1) Supraglottis: from inferior surface of epiglottis to vocal folds (ie. the false vocal cords).
2) Glottis: vocal cords and 1cm below them. The opening between the vocal cords is known as rima glottidis, the size of which is altered by the muscles of phonation
3) Subglottis – From inferior border of the glottis to the inferior border of the cricoid cartilage
42
Borders of the larynx:
Superior: Inferior boarder epiglottis
Inferior: Inferior border of cricoid cartilage (same as hypo pharynx).
43
The opening between the vocal cords is known as?
The opening between the vocal cords is known as rima glottidis, the size of which is altered by the muscles of phonation
44
The lining of the larynx:
The vocal cords are non-keratinised stratified squamous epithelium (i.e. think vocal cord SCC),
The rest is respiratory epithelium: ciliated columnar epithelium.
45
Describe the unpaired components of the cartilaginous skeleton of the larynx:
There are 3 paired and 3 unpaired components
Unpaired (the easy ones)
1) Epiglottis - heart shaped covered in mucous membrane. Forms
2) Thyroid cartilage: 2 laminae fusing anteriorly to form the laryngeal prominence. Superior border at the level of C4 where thyrohyoid membrane suspends the larynx from the hyoid. Inferior border has thyrocricoid membrane.
3) Cricoid cartilage: Signet ring with band facing anteriorly. Only complete ring of cartilage along the airway. Suspended from thyroid cartilage. The fibrous capsule of the thyroid is fused with the anterior surface./
46
Describe the paired components of the cartilaginous skeleton of the larynx:
Paired:
1) Arytenoid: Pyramid shaped cartilages. Apex superiorly, vocal process anteriorly, muscular process laterally. Movements allow tensing and relaxing of the vocal cords
2) Cuneiform
3) Corniculate
47
The muscles of the neck can be divided into?
| Based on?
Intrinsic and extrinsic:
Extrinsic muscles move the larynx as a whole
Intrinsic alter the length and tension of the vocal folds
48
The extrinsic muscles of the larynx can be broken into:
outer aspect and internal
Outer aspect into:
- The suprahyoid muscles elevate the larynx,
Includes stylopharyngeus
- The infrahyoid muscles depress it
49
A tracheostomy goes through what?
A cricothyroidotomy goes through the median cricothyroid ligaments (there is also a median thyrohyoid ligament) - so there is 2 extra ligaments to name in an exam.
50
What connects the arytenoid cartilage with the epiglottic cartilage?
What does it form?
Quadrangular membrane:
- connects the arytenoid cartilage with the epiglottic cartilage, forming skeleton of the aryepiglottic fold
- Its free inferior edge forms the vestibular ligament
51
What is "special" about the cricothyroid?
What about the other muscles
The cricothyroid is the only intrinsic muscle external to the larynx. It tenses the vocal cords
Also supplied by the external branch of the superior laryngeal nerve (all the rest of the intrinsic are supplied by a branch of the recurrent)
The remainder of the muscles form a sphincter around the laryngeal inlet.
52
Intrinsic muscles of the larynx:
```
(all are paired)
Cricothyroid
Thyroarytenoid
Posterior cricoarytenoid (important)
Lateral cricoarytenoids
Transverse and Oblique Arytenoids
```
53
Which muscles abduct the vocal cords?
Only the POSTERIOR cricoarytenoids abduct the cords, all other muscles function to oppose the vocal folds.
54
Parts of the thyroid cartilage
Composed of two lateral plates (laminae) which meet in the midline anteriorly, forming the:
Laryngeal prominence
Posterior border of each sheet project superiorly and inferiorly to form the:
Superior and
Inferior horns (also known as cornu)
55
Arterial supply to the Larynx:
Superior laryngeal artery
Branch of the superior thyroid artery
Inferior laryngeal artery,
branch of inferior thyroid artery
56
Venous supply to the larynx:
Superior laryngeal vein
drains to the internal jugular vein via the superior thyroid
Inferior laryngeal vein
drains to the left brachiocephalic vein via the inferior thyroid vein
57
Easy thing to remember about the blood supply to the larynx:
Superior and inferior aa/vv all drain to inf and sup thyroid aa/vv's
Lymphatics is similar (but remember level 4, pre/paratrachial nodes drain to deep cervical)
58
Lymphatic drainage of the larynx:
Above vocal folds = Follow superior laryngeal artery to drain into superior deep cervical nodes. (levels III, occasionally level II)
Below vocal folds = follow similar pathways to tracheal lymphatics, and end in pre- or para-tracheal nodes (level VI). From here they drain to deep cervical nodes (levels III, IV).
There are no lymphatics of the vocal folds. If tumours in this region advance to the point of invading surrounding parts of the larynx, they may spread along either pathway.
59
Where is the inferior vagal ganglion, and what arises from it?
The superior laryngeal nerve usually arises from the inferior vagal ganglion (near the jugular foramen).
Descends within the carotid sheath, which it leaves at about the level of the hyoid bone. It accompanies the superior thyroid, and then the superior laryngeal artery through the thryohyoid membrane to supply the mucosa of the supraglottic larynx. A small branch innervates the cricothyroid muscle, the only intrinsic muscle innervated by this nerve.
60
Innervation of the larynx:
Superior laryngeal nerve: Sensation to the suprglottic region, innervation of the cricothyroid.
Recurrent laryngeal: everything else
Passes deep to inf constrictor.
61
What are the pharyngeal constrictors?
During swallowing, these muscles act to shorten and widen the pharynx.
They are innervated by the pharyngeal branch of the Vagus nerve (CN X) with the exception of the stylopharyngeus muscle which is innervated by the glossopharyngeal nerve (CN IX).
62
Describe the pharynx:
A fibromuscular tube extending from the base of the skull to the C6 vertebrae (inferior boarder of cricoid) .
Around 12cm.
Connecting the oral and nasal cavities to both the respiratory tract (trachea) and GIT (oesophagus) at it inferior ends.
Has functions both as conduit, immune surveillance, airway protection,
Divided into three parts:
Nasopharynx
Oropharynx
Laryngopharyn
63
Walls of the pharynx:
3 layers:
Mucosa (respiratory epithelium in nasopharynx)
Submucosa - Fibrous layer
Muscular layer:
- 3 circular (sup, mid, inf)
- 3 paired longitudinal ( -pharyngeus) muscles - named for where they go:
stylopharyngess, Palatopharyngeus, Salphingopharyneus
64
Describe the mucosal layer of the pharynx:
Nasopharynx: ciliated columnar epithelium
Oropharynx: stratified squamous epithelium Laryngopharynx: stratified squamous epithelium
65
Arterial supply to the pharynx:
1) Ascending laryngeal (1st branch of ECA)
2) Superior thyroid (2nd branch, lingual is 3rd)
3) Ascending palatine and tonsillar arteries, which are the 1st branches of facial artery (which is 4th branch of ECA)
4) Greater palatine and pharyngeal maxillary artery. (i.e. maxillary artery is terminal branch of ECA, along with?)
66
Venous drainage of the pharynx?
The pharyngeal plexus drains to left and right INTERNAL JUGULAR veins
67
Sensory innervation of the pharynx:
Nasopharynx: V2 supplies upper and anterior nasopharynx (also the posterior part of the nasal cavity, and most of the palate and upper gums of the oral cavity).
The lingual and pharyngeal branches of the glossopharyngeal nerve supply the lower part of the nasopharynx (also the posterior third of the tongue, and part of the soft palate and oropharynx).
(REMEMBER the Pharyngeal plexus!!!)
Oropharynx: Glossopharyngeal nerves via the pharyngeal plexus
Hypo pharynx: Remember the good ol' superior laryngeal nerve and its nearby friend the supra glottis region of the larynx? Well he's back, along with his friend CNIX (Via the pharyngeal plexus!!) to bring you sensory information from the hypophyarnx. Fuck yeah.
68
Motor innervation of the pharynx?
Its all vagus baby (except stylopharyngeous - that cat gets down with ol' CN IX).
69
The pharyngeal plexus has contributions from?
CN IX, CNX, cervical sympathetic chain.
70
Borders of the nasopharynx:
```
Superior: Sphenoid (basiosphenoid)
Inferior: soft palette
Anteriorly: posterior nares and posterior margin of nasal septum
Posterior: C1 and C2
Lateral:
Fossa of Rossenmuller (pharyngeal recess)
Pharyngeal opening of Eustachian
Surrounding tubal tonsils
```
71
Venous drainage of the nasopharynx and general principle of venous drainage of the pharynx:
veins: occur via plexi (the nasopharynx has a plexi) which drain into the internal jugular vein
- pterygoid plexus
- pharyngeal plexus
72
Anatomic boundaries of oropharynx:
Anterior: vertical plane defined by circumvallate papillae, anterior tonsilar pillars and border between hard and soft palate.
Posterior: posterior wall of pharynx C3 to?
Superior free edge of soft palate
Lateral: Tonsillar fossae and posterior pillars
73
Waldeyer's ring comprises:
```
Waldeyer's ring comprises the:
nasopharyngeal tonsil or adenoid,
the paired tubal tonsils,
the paired palatine tonsils and
the lingual tonsil.
```
The surface of the tonsils covered with pharyngeal epithelium.
74
sub sites of the oropharynx:
1) base of tongue,
2) tonsil and pillars, and
3) uvula, soft palate, and posterior pharyngeal wall.
75
Contents of the oropharynx:
```
Base of tongue
Tonsils: lingular and palatine
Posterior pillar
Uvula
Vellecula
Inferior surface soft palate
Posterior wall oropharynx
```
76
Describe the tongue:
The tongue is a complex, mobile principally muscular organ that extends from the oral cavity (anterior 2/3) to the oropharynx (containing the posterior 2/3).
The anterior 2/3 = mobile tongue: includes root of tongue,
The posterior 1/2 = fixed: base of tongue which contains the lingual tonsils
The tongue is covered by a mucosa, which is roughened on the dorsal surface covered by filiform, fungiform and circumvallate papillae.
It has important roles in speech (articulation), swallowing, mastication, taste, oral cleansing and
77
Anatomic relations of the tongue:
Anteriorly and laterally = teeth and lingual gingivae
Superiorly = hard and soft palate
Inferiorly = floor of mouth
Posteriorly = posterior pharyngeal wall and lingual surface of the epiglottis
78
The dorsal anterior 2/3rds of the tongue is covered by?
Vallate papillae
• Large flat-topped
• immediately anterior to the sulcus terminalis
• house taste buds
Foliate papillae
• Lateral folds of lingual mucosa
• Poorly developed in humans
Fungiform papillae
• mushroom shaped
• scattered on the sides and apex of the tongue. They also contain taste receptors.
Filiform papillae
• Long and numerous and cover the surface of the tongue.
• contain nerve endings sensitive to touch.
• Arranged in V shaped rows parallel to terminal sulcus, except at apex, where they are transvers
79
Describe the muscles of the tongue:
Composed of 4 intrinsic and 4 extrinsic muscles
80
Arterial supply nasopharynx:
- Ascending pharyngeal arteries
- Ascending palatine branch of facial artery
- Ascending cervical artery
- Maxillary artery
81
Anatomical borders of the palatine tonsils:
Anterior: Anterior tonsillar pillars (folds of mucosa made by the paired palatoglossus muscles)
Posterior: Posterior tonsillar pillars (1 of the 5 paired longitudinal muscles of the pharynx paired create ridges of mucous membrane in the lateral pharyngeal wall called the palatopharyngeal arches)
Lateral: Palatine fossa containing the superior pharyngeal constrictor.
Medial: pharyngeal mucosa and oropharynx
82
Arterial supply to the palatine tonsils:
Primarily from the tonsillar branch of facial artery (remember 1st 2 branches are ascending palatine and tonsillar arteries), with contributions from the ascending pharyngeal, lingual and ascending palatine arteries
83
Venous drainage palatine tonsils:
Tonsillar venous plexus drains to pharyngeal plexus which in turn drains internal jugular veins
84
Lymphatic drainage palatine tonsils:
What of the oropharynx generally?
Channels drain unilaterally through the reteropharynx to jugulodiagstric/deep cervical nodes.
The oropharynx and tonsil drain through the peripharyngeal space to the midjugular region, particularly to the jugulodigastric nodes.
85
Borders of the oral cavity:
Anterior:starts at the portion of the lip that contacts the opposed lip (wet mucosa) and excludes the dry vermilion lip.
Posterior (i.e. the nat border of the oropharynx): Vertical coronal plane through a ring of structures (circumvallate papillae, anterior tonsillar pillars, and junction of hard and soft palates).
86
Subsides of the oral cavity:
- mucosal lip
- buccal mucosa
- upper alveolar ridge (mucosa overlying alveolar process of maxilla)
- lower alveolar ridge (mucosa overlying alveolar process of mandible)
- retromolar gingiva (retromolar trigone)
- floor of mouth
- anterior two-thirds of the tongue (oral tongue; posterior third is part of the oropharynx)
hard palate
87
Lymphatic drainage of the oral cavity:
The drainage of the tongue is another card (but general principles are the same.
Channel towards the midline drain increasingly bilaterally, moving away from mid lining more unilaterally.
More anteriorly and medially (Medial lower lip, anterior medial FOM, and tip of tongue) drain to submental nodes (which drain to submandibular the jugulodigastric/deep cervical nodes).
More laterally and less anteriorly drain to submandibular nodes.
88
Describe the hard palate:
The anterior horizontal bony part of the palate forms the roof of the oral cavity and floor of the nasal cavity.
Most of the hard palate is formed by the palatine processes of the maxillae, the horizontal plates of the palatine bones complete it posteriorly.
On its inferior oral surface it is lined by oral mucosa (containing innumerable palatine glands) and on its superior nasal surface it is lined by respiratory mucosa.
89
Besides the tongue name some anatomical contents in the floor of the mouth (imagine the tongue is lifted up):
Lingual frenulum, on either side at the base of this are the sublingual carbuncles with openings of the submandibular ducts.
More laterally the sublingual fold parallels the teeth and contains the sublingual ducts.
90
Potentially the only feature of the oral hard palate you may have to name in the exam:
Transverse palatine folds.
91
Name the groups of glans the empty into the oral cavity and the sites at which they do this:
1) Submandibular glands - paired submandibular ducts - empty into FOM via openings in the sublingual caruncles.
2) Sublingual glands - via numerous sublingual ducts along sublingual fold.
3) Parotid gland - Parotid duct (Stensen duct), surrounded by buccal fat pad tuns over lateral boarder of masseter passes through buccinator emptying via the parotid papilla.
92
Where is the parotid papilla?
Adjacent the 2nd upper molar.
93
Describe the parotid gland
Paired/bilateral structure. Largest of the 3 paired salivary glands. The superficial surface is approximately triangular, 5cm high, 4cm deep, 3cm wide.
Lobulated irregular shaped, it can be divided into deep and superficial lobes, separated by the facial nerve.
Along with the masseter lies within a depression known as the parotid region (this region has SCM as posterior border, zygomatic arch superior, masseter anteriorly, inferior border of mandible inferiorly)
94
Anatomic relations of the parotid gland:
Superiorly: EAM and TMJ
Anteriorly: Mandible, post border of masseter and medial pterygoid.
Posteriorly: Mastoid process, SCM, carotid sheath (deep posterior)
Superficial: Superficial parotid lymph nodes, parotid sheath, skin
Deep: The external carotid enters inferiorly on this surface along with retromandibular vein, Carotid sheath (posterior and deep) and pharynx
WITHIN: Facial nerve and its main branches, terminal branches of ECA (mandibular and superficial temporary + its branch the transverse facial), tributaries to the retromandibular vein (superficial temporal vein).
95
Innervation of the parotid:
Sensory:
The meat - auriculotemporal nerve (a branch of V3)
The fascia - great auricular nerve (from C2 and C3)
Drool:
Glossopharyngeal nerve gives parasympathetic fibres to the otic ganglion which then travel in the auricular temporal nerve.
Not drool
Sympathetic innervation superior cervical ganglion. Fibres travel along the external carotid artery to reach the parotid. Sympathetic nervous system inhibits saliva secretion, via vasoconstriction.
96
Lymphatic drainage of the parotid:
* Lymph from the superficial parotid drains
* into the parotid lymph nodes and then to the upper deep cervical nodes.
* Lymph from the deep lobe drains • to the retropharyngeal nodes
97
Arterial supply to the parotid:
External carotid artery
98
Venous drainage of the parotid:
Retromandibular vein
99
Compare the secretions of the different salivary glands
The parotid produces a serous secretion,
the sublingual a mucous secretion,
and the submandibular a mix of the two.
100
Describe the submandibular gland:
1 of three paired salivary glands
Ovoid in shape and roughly thumb sized.
Produces a mix of serous and mucous saliva.
Lies along the body of the mandible, both partly deep and partly superficial to the mylohyoid
muscle.
101
Describe the parts of the submandibular gland
Wraps around the posterior border of mylohyoid, with a large superficial part and a smaller deep nubbin rubbn' up on hyoglossus under the FOM mucous membrane.
102
Describe the anatomical relations of the superficial par of the submandibular gland:
Superior: Mandible and insertion of mylohyoid.
Anterior: mylohyoid
Posterior: reaches sheath of parotid
Lateral: Mandible and platysma
Medial: Mylohoid
Inferior: Hypoglossal nerve and cervical branch of facial nerve.
103
How long is the submandibular duct?
| Describe its course
5cm.
Courses anteriorly from the deep part of the submandibular gland between hyoglossus mylohyoid.
The lingual nerve winds around it as it courses anteriomedialy below the mucosa of the FOM.
Opens into the oral cavity at the lingual caruncles.
104
Lymphatic drainage of submandibular glands:
Channel direct to the sub mandibular gland which drains to deep cervical nodes
105
Arterial and venous supply to the submandibular gland:
Lingual and facial arteries and veins
106
Describe the sublingual glands:
Paired midline salivary gland
Smallest of the 3 paired glands
Almond shaped, left and right join anteriorly to form a horse shoe.
Produces more mutinous saliva.
Lies below the mucosa of the FOM, anterior to the deep part of the submandibular gland.
Numerous ducts along the lingual fold open to the oral cavity AS WELL AS into the submandibular duct.
107
Arterial/venous supply to sublingual glands:
Sublingual and submittal aa/vv
108
Nerve supply to submandibular and sublingual nodes:
Sensory: Lingual nerve branch of V3
Drool: Parasympathetic fibres from chord tympani (VII), and glossopharyngeal nerve (IX) the later via the otic ganglion. Fibres descend with the lingual nerve.
Dont drool: Sympathetic fibres from upper cervical plexus (C2, C3) travel with arteries (periarterial plexus)
109
3 key branches of V3:
Buccal
Lingual
Inferior alveola
110
Which salivary gland produces the most saliva?
The sub mandibular gland produces 70%
111
Anatomical boundaries of the hypo pharynx:
Superior: Inferior border of hyoid bone/superior border of epiglottis
Inferior: Inferior border of cricoid cartilage (C6)
Anterior: Inlet of larynx, post-cricoid mucosa, posterior cricoarytenoid muscle
Posterior: Posterior pharyngeal wall, vertebral bodies C3 to C6
112
The inferior border of the cricoid cartilage is at what vertebral level?
Inferior border of the cricoid cartilage = C6
113
What surrounds the hypo pharynx laterally:
The medial and inferior constrictors.
114
Briefly describe the sub sites of the hypo pharynx:
pyriform sinus/fossa: pear-shaped (pirum) located posterolaterally to either side of the laryngeal opening. Beneath the mucous membrane of the anterior wall runs the internal laryngeal nerve.
postcricoid region: anterior wall of hypoharynx. The area includes the mucosa, intramural fat, and a rich venous plexus.
Posterior wall: behind which is the retrophaynx, from C3-inferior border C6.
115
Lymphatic drainage of the subsites of the hypo pharynx:
1) pyriform sinus - drain primarily to the upper and middle jugular nodes
2) postcricoid region - middle and lower jugular nodes and to the paratracheal nodes.
3) posterior wall - jugular nodes and retropharyngeal nodes
116
The nasal concae are formed by which bones?
Sup and middle by ethmoid
| Inferior is the inferior concha bone
117
Bones of the nose (not cavity):
Nasal bones,
Frontal process of maxilla and
Nasal part of frontal bone
118
The cartilaginous part of the nose consists of:
2 paired cartilages:
2 lateral
2 ala
1 Septum
119
Describe the nasal cavity:
Paired midline cavity, seperated by septum, of the skull forming communication from nares to nasopharynx (posterior border of chance).
Structure somewhat triangular with roof (apex), floor and lateral and medial walls.
Function is that of the nose (smell, respiration, filtration, humidification)
superior 1/3 is olfactory mucosa, inferior 1/3 respiratory
Covered in respiratory epithelium bound to periosteum (with exception of nasal vestibule which is skin).
Communicates and is continuous with paranasal sinuses.
120
Describe the structure of the nasal cavity
Roof - the site of olfactory mucosa, formed by nasal bone cribiform plate of ethmoid), frontal bones and posteriorly anterior wall of sphenoid sinus.
Floor: Palantine process of maxilla, posteriorly horizontal plate of palatine bone.
Lateral walls: superior and middle conchae (parts of ethmoid), inferior conchae is its own bone.
Medial wall: Nasal septum.
The conchae divide the cavity into 4 spaces:
a) Sup meatus
b) Middle meatus
c) Inferior meatus
d) Spheno-ethmoidal recess
121
The conchae divide the nasal cavity into 4 spaces:
What do they communicate with?
a) Sup meatus - posterior ethmoidal sinus
b) Middle meatus – Frontal, maxillary and middle ethmoid
c) Inferior meatus – NASOLACRIMAL DUCT
d) Spheno-ethmoidal recess - Sphenoid sinus empties.
122
Name the holes in the lateral wall of the nasal cavity.
Inf meatus - opening of lacrimal duct
**** Middle - semi-lunar hiatus (openings for maxillary frontal and middle ethmoid)
Superior meatus: Ethmoid bulla
Sphene-ethmoidal recess: opening of ethmoid sinus.
123
Arterial supply to nasal cavity:
Ethmoid arteries: Anterior and posterior (via formen in ethmoid from ICA)
Sephenopalantine artery: Branch of maxillary artery
Greater palatine (branch of maxillary)
Superior labial (branch of facial)
124
Sensory innervation of the nasal cavity:
Septum:
• nasopalatine nerve (branch of
maxillary nerve)
**** • nasociliary nerve (branchof the ophthalmic nerve).
External skin of the nose = V2
Cavity:
• inferior 2/3 by nasopalatine n. (branch of V2)
• superior and anterior by anterior ethmoidal n. (V1)
• lateral wall by nasal branches of maxillary(V2)
125
Symp and parasymp innervation of nasal cavity:
The nasopalantine nerve has sympathetic fibres it picked up from the pterygopalantine ganglion.
126
Lymphatic drainage of the nasal cavity:
Drains inferiorly to sub-mandibular - then Cx chain
| Drain posteriorly to reteropharyngeal nodes
127
Relations of the temporal fossa:
Superior: inferior and superior temporal lines
Inferior: Infratemporal crest
Anterior: zygomatic bone
Lateral: Zygomatic arch
128
What bones make up the temporal fossa:
Temporal (squamous), frontal (vertical plate), sphenoid (greater wing), parietal (pars plannum)
(bones that form part of Pterion)
129
Origin, insertion, action and innervation of temporalis:
Arises from bony floor and fascia of supra temporal and infra temporal crest. Insertion is LATERAL surface of coronoid, so as to elevate and retract the jaw. Innervation both sensory and motor by deep temporal branches of V3 (i.e. V3 does all the muscles of mastication)
130
Muscles of mastication:
Besides the face the all attach to the mandible, what is a big difference between them and the other facial muscles (the thing I think is important but might not actually be important, so just flick over the card).
1) Lateral pterygoid
2) Medial pterygoid
3) Masseter
4) Temporalis
All the the facial muscles are motor VII
131
The zygomatic arch is formed by:
Processes of squamous temporal bone, and zygomatic bone (Meet at a suture). Completed by zygomatic process of maxilla
132
Brief description of the infra temporal fossa:
AKA?
Space lying beneath the base of skull between the side wall of the pharynx and the ramus of the mandible
AKA
• parapharyngeal space
• lateral pharyngeal space
133
Medial boundary of infra temporal fossa (high yield exam question):
* Lateral surface of lateral pterygoid plate and tensor palati muscle and superior constrictor
* pterygo-maxillary fissure in front of lateral pterygoid plate (the communication between the infratemporal fossa and the pterygopalatine fossa)
134
Lateral, anterior and floor of infra temporal fossa:
Lateral wall
• Ramus of mandible and its coronoid
process
Anterior
• Posterior surface of maxilla
• Inferior orbital fissure= gap between maxilla and greater wing of sphenoid
Floor
• Medial pterygoid attaches to mandible
• Near angle of mandible
135
What forms the roof of the infra temporal fossa? What important shit happens up there?
Formed medially by the infra-temporal surface of the greater wing of sphenoid which contain foramen ovalis (V3) and spinosum (recurrent middle meningeal branch of V3). Remember spinousum opens into the pterygopalantine fossa.
136
Posterior border of the lateral pharyngeal space:
Posteriorly
• Styloid process and carotid sheath behind it
• Tympanic plate/mastoid
137
Contents of the infra temporal fossa:
Nerves:
Motor and sensory branches of Mandibular nerve and its recurrent meningeal branch.
Chorda Tympani
Otic ganglion
Muscles of masturbation
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Vessels:
Maxillary artery
Maxillary vein
Pterygoid venous plexus
Middle meningeal vein (goes through spinosum)
```
138
The lingual nerve is made up of what branches?
Which provide what function?
Largely a branch of V3 - providing sensation/general somatic afferents
Joined by chord tympani - taste anterior 2/3rds of tongue
139
What is the otic ganglia?
Found immediately below the foramen ovale in the infratemporal fossa and on the medial surface of the mandibular nerve.
It is functionally associated with the glossopharyngeal nerve and innervates the parotid gland for salivation (parasym).
140
Sensory branches of V3:
Auriculotemporal
Buccal
Inferior alveolar
Lingual
141
What bones makes up the orbit?
Superior wall –
• formed mainly by the orbital plate of the frontal bone separating the orbital cavity from the anterior cranial fossa and the frontal lobe of the brain
• The roof near the apex (posteriorly) is formed by the lesser wing of the sphenoid
• At the base, the frontal bone has a notch through which the supraorbital nerve passes to supply the forehead
Medial wall –
• 5cm long - formed by the maxilla, lacrimal, ethmoid and sphenoid bones
• Anteriorly, the medial wall is indented by the lacrimal groove which accommodates the lacrimal sac and the proximal part of the nasolacrimal duct.
Inferior wall –
• formed mainly by the orbital plate of the maxillary bone
• Separated from the lateral wall by the inferior orbital fissure
• Laterally; zygomatic bone
• Posteriorally palatine bone
Lateral wall –
• 5cm long - formed by the frontal process of the zygomatic bone and the greater wing of the sphenoid
5
142
Describe the eye:
* bilateral and spherical organ
* 25mm diameter
* houses the structures responsible for vision • lies in the bony orbit
Divided into the 3 layers
• fibrous,
• vascular
• Inner/nervous layers
143
Layers of the eye:
Divided into the 3 layers
• fibrous: Sclera (85%) and cornea ( in continuity)
• vascular: Cilliary bodies, choroid, iris
• Inner/nervous layers: retina - neural and pigmented layers.
144
Respiratory epithelium:
Ciliated pseudostratified columnar epithelium, with goblet cells ect.
145
How many paranasal sinuses are there?
Name them:
```
4 paired:
Ethmoid air cells
Sphenoid
frontal
Maxillary.
```
146
The frontal sinus drains via? to where?
By frontonasal duct
• into the middle meatus
• via the hiatus semilunaris
