Head and Neck Anatomy Flashcards
1
Q
Arterial supply of thyroid gland
A
- Superior thyroid artery - upper pole. Comes from ECA
- Inferior thyroid artery - lower pole. Thyrocervical trunk from the subclavian artery
- Thyroid ima artery in 10% of patients coming from aortic arch
2
Q
Venous drainage of thyroid gland
A
- Superior thyroid vein
- Middle thyroid vein
- drain to Internal jugular - Inferior thyroid vein
- drains to left brachiocephalic vein (both lobes)
3
Q
Lymphatic drainage of thyroid
A
Prelaryngeal
Pretracheal
Paratracheal
Upper and lower deep cervical LNs
4
Q
Infrahyoid/strap muscles location
A
Run between hyoid bone, thyroid cartilage and sternum
5
Q
A
31 - sternohyoid
32 - sternothyroid
38 - thyrohyoid
34 - omohyoid - superior and inferior bellies divided by ligament
6
Q
Nerve supply of strap muscles
A
Ansa cervicalis C1 - C3
Except thyrohyoid - C1 only
7
Q
Action of strap muscles
A
Depress the hyoid and larynx during swallowing and speaking
8
Q
Describe embryology of thyroid
A
Develops from foramen caecum which is between anterior 2/3 and posterior 1/3 of base of tongue and travels down, loops around hyoid and then arrives to position in neck
9
Q
Defects in thyroid embyrology
A
Incomplete descent - lingual, sublingual, pre laryngeal or pretracheal thyroid
Failure of closure of pathway of descent - thyroglossal duct cyst
10
Q
Why does the thyroid move up with deglutition
A
Thyroid grand is within the pre tracheal fascia which is attached to thyroid cartilage and hyoid bone. The digastric muscle contracts and pulls the hyoid bone and thyroid cartilage which pulls the pretracheal fascia and the thyroid
11
Q
Commonly injured nerves during thyroidectomy
A
Common - External laryngeal nerve (near to superior thyroid artery)
Recurrent laryngeal nerve (close to inferior thyroid artery)
Less common - cervical sympathetic chain - ischemia due to ligation of the inferior thyroid artery trunk
12
Q
What is the nerve supply of the laryngeal muscles
A
All laryngeal muscles supplied for RLN except cricothyroid supplied by ELN
13
Q
Sensory supply of larynx
A
Above vocal cords - internal laryngeal nerve
Below - RLN
14
Q
Attachments of the vocal cords
A
Anterior - thyroid cartilage
Posterior - arytenoid cartilage
Lateral - laryngeal muscles
Medial - free border
15
Q
Which muscles open the vocal folds
A
Posterior cricoarytenoid
16
Q
Which muscles close the vocal folds
A
Lateral cricoarytenoid
17
Q
Which muscles tense/lengthen the vocal cords
A
Cricothyroid muscles
18
Q
Location of parathyroid glands
A
2 on posterior aspect of each lobe of the thyroid
19
Q
Embryology of parathyroids
A
Inferior parathyroid - 3rd pharyngeal pouch with the thymus
Superior parathyroid - 4th pharyngeal pouch
20
Q
Arterial supply of parathyroid
A
inferior thyroid artery
21
Q
Injury to RLN
A
Unilateral injury -
Partial - dyspnea on exertion
Complete - hoarseness of voice
Bilateral injury
Partial - respiratory compromise (both vocal cords adducted)
Full - unable to speak or cough (cords half abducted position)
22
Q
Age at which the cranial sutures ossify
A
18-24 months
23
Q
What is it called if cranial sutures are fused at birth
A
Craniosynostosis
24
Q
When does the mastoid bone develop
A
At 2 years of age
25
What are the diploic veins
Short veins found in the skull that drain the diploid space (bone marrow containing space) to the dural venous sinuses
26
1 - frontal
2 - maxillary
3 - ethmoid
4 - sphenoid
27
What forms the pterion
Union of 4 bones - frontal, parietal, temporal, sphenoid
28
what lies beneath the pterion and what happens if it is injure
middle meningeal artery
Extra dural haemorrhage
29
What muscles attach to the styloid process
Stylohyoid
Styloglossus
Stylopharyngeus
30
What are the articulating surfaces of TMJ
mandibular fossa of temporal bone and articular tubercle
mandibular head/condylar process of mandible
31
What type of joint is the TMJ
Bi arthroidal condyloid hinge joint
32
Movements at TMJ
Opening of the mouth, closing, protrusion, retraction and side to side movement
33
Muscles which cause opening of mouth
Digastric
Lateral pterygoid
Geniohyoid
Mylohyoid
33
What are the layers of the scalp
Skin
Connective tissue
Aponeurosis
Loose areolar tissue
Periosteum
34
What are the layers encountered on pterion burr holing
Skin
Connective tissue
Aponeurosis of occipitofrontalis
Temporalis fascia - superficial and deep layers
Temporalis muscle
Periosteum
35
Temporalis muscle blood supply
Anterior and posterior deep temporal arteries
Arise from the maxillary artery (terminal branch of ECA)
36
What is the arterial supply of skin of scalp over temporalis muscle
Superficial temporal artery - direct branch of ECA
37
3, 9, 10, 11, 12, 15, 20, 47
10 - foramen magnum
15 - hypoglossal canal
20 - jugular foramen
3 - carotid canal
9 - foramen lacerum
47 - stylomastoid foramen
11 - foramen ovale
12 - foramen spinosum
38
What passes through foramen magnum
Tissues
Apical odontoid ligament
Tectorial membrane
Nerves
Spinal root of accessory nerve
Lower end of medulla oblongata
Vessels
BL vertebral arteries
Anterior and posterior spinal arteries
39
What passes through jugular foramen
Glossopharyngeal vagus nerve and accessory nerve
Internal jugular vein
Inferior petrosal sinus
40
What passes through stylomastoid foramen
Facial nerve and stylomastoid artery
41
What passes through carotid canal
Internal carotid artery
Sympathetic plexus
Deep petrosal nerve
Emissary veins
42
What passes through foramen lacerum
Lower half is obliterated by fibrocartilage
Upper half - ICA, greater and deep petrosal nerves
43
1, 4, 8, 12, 13, 14, 15, 24, 27, 28, 30, 32, 34, 37, 38, 41, 42, 43, 44
1 - anterior clinoid process
4 - clivus
8 - dorsum selli
12 - foramen ovale
13 - foramen rotundum
14 - foramen spinosum
15 - frontal crest
24 - floor of temporal bone
27 - hypoglossal canal
28 - internal acoustic meatus
30 - jugular foramen
32 - lesser wing of sphenoid
34 - optic canal
37 - petrous part of temporal bone
38 - sella turcica
41 - squamous part of temporal bone
42 - superior orbital fissure
43 - tegmentum tympani
44 - trigeminal impression (trigeminal ganglion)
44
What does the frontal crest give attachment to
Falx cerebri - the superior saggital sinus passes through this
45
Where does the pituitary gland sit
Sella turcica
46
What cranial nerve tracks on the clivus
Abducent nerve
47
What is the name of the juvenile structure that forms the clivus
Spheno occipital synchondrosis -
Fusion of the sphenoid and occipital bones - age 13 in girls and 15 in boys
48
What passes through optic canal
Optic nerve
3 layers of meninges
Ophthalmic artery
Sympathetic nerves
49
What passes through foramen rotundum
maxillary division of trigeminal nerve
50
What passes through the foramen ovale
Otic ganglion
V - mandibular division of trigeminal
Accessory meningeal artery
Lesser petrosal nerve
Emissary veins
51
What passes through foramen spinosum
Middle meningeal artery
52
How does middle ear infection spread to cranial cavity
Erosion of tegmentum tympani
53
What passes through superior orbital fissue
Lacrimal nerve
Frontal nerve
Nasociliary nerve
Trochlear nerve
Superior and inferior division occulomotor nerve
Adbucent nerve
Superior and inferior ophthalmic vein
54
What passes through internal acoustic meatus
Vestibulocochlear nerve
Facial nerve
labyrinthine artery
55
What is the intra cranial course of facial nerve
Originates between pons and medulla -> IAM -> facial canal (petrous temporal bone) -> exits through stylomastoid foramen
56
Branches of facial nerve in face
57
What muscle in the ear is supplied by facial nerve
Nerve to stapedius
58
What is the difference between UMNL and LMNL facial palsy
UMNL - affects the lower half of contralateral side of face. Upper half will be spared
LMNL - affects whole of face on ipsilateral side
59
Why do patients with acoustic neuroma hear louder on the affected side
Involvement of facial nerve causes paralysis of stapedius muscle. Stapedius functions to control the oscillation of the stapes and dampen the waveform. This results in hyperacusis
60
What are the causes of lytic skull lesions
Metastases
Multiple myeloma
Pagets disease
Haemangioma
Osteomyelitis
Sarcoidosis
61
What are the bones forming the middle cranial fossa
Sphenoid and temporal
62
What are the boundaries of middle cranial fossa
Anterolateral - lesser wing of sphenoid
Anteromedial - Limbus of sphenoid
Posteromedial - dorsum selli
Posterolateral - Petrous part of temporal
Floor - greater wing of sphenoid and squamous and petrous parts of temporal bone
63
Contents of middle cranial fossa
Pituitary gland and temporal lobes of brain
64
Posterior cranial fossa bones
Occipital and part of temporal bones
65
Boundaries of posterior cranial fossa
Anteromedial - dorsum selli
Anterolateral - superior border of petrous part of temporal bones
Posterior - squamous part of occipital bone
Floor - Mastoid part of temporal bone and the occipital bone - occipital, condylar and basilar parts
66
Contents of posterior cranial fossa
Brainstem and cerebellum
67
Identify the bones involving a trans - sphenoidal basilar skull fracture
Tympanic and [etrous part of temporal bone
Posterior wall of sphenoid sinus
Sphenopetrosal synchondrosis and carotid canal
Ends at either squamous or tympanic part of temporal bone
68
Benign tumours of posterior cranial fossa
Acoustic neuroma
Ependymoma
69
Where does the Cavernous sinus drain blood from and to
Drains from -
superior ophthalmic veins and facial vein
Sphenoparietal sinus
Drains to -
Superior and inferior petrosal sinuses
Inter cavernous sinuses
70
Contents of cavernous sinus
Wall of sinus:
Oculomotor nerve (3)
Trochlear nerve (4)
Ophthalmic and maxillary parts of trigeminal (5)
Middle of sinus
Abducent (6)
ICA
71
Where are the cavernous sinuses located
On either side of the sella turcica
72
What is the dangerous area of the face
Medial angle of eye
Nose
Lips
73
Signs of cavernous sinus thrombosis
Painful swelling of eye
Ophthalmoplegia (paralysis of cranial nerves moving eye)
Gradual loss of vision
74
Which are the unpaired venous sinuses
Superior and inferior sagital sinuses
Straight sinus
Occipital sinus
Confluence of sinuses
75
Superior sagital sinus site and where does it drain from and to
Site - superior border of falx cerebri
Drains from - diploid veins of skull and superior cerebral veins
Drains to - confluence of sinuses
76
Inferior sagittal sinus site and where does it drain from and to
site - inferior border of falx cerebri
Drains from - medial part of both cerebral hemispheres
Drains to - straight sinus
77
Straight sinus site and where does it drain from and to
Site - superior border of tentorium cerebelli
Drains from - inferior sagital sinus, great cerebral vein (of Galen)
Drains to - confluence of sinuses
78
Occipital sinus site and where does it drain from and to
Site - inner table of occipital bone
Drains from - internal venous plexus
Drains to - confluence of sinuses
79
Confluence of sinus location and where does it drain from and to
Occipital protuberance
Drains from superior sagittal sinus, straight sinus and occipital sinus
Drains to both transverse sinuses
80
Paired venous sinuses
Sphenoparietal sinus
81
Sphenoparietal sinus site and drainage
Site - lesser wing of sphenoid
Drains from - superior cerebral vein
Drains to - cavernous sinus
82
Superior petrosal sinus site and drainage
Site - superior petrosal sulcus
Drains from - cerebellar veins, inferior cerebral vein and labyrinthine vein and cavernous sinus
Drains to - Sigmoid sinus
83
Inferior petrosal sinus site and drainage
Site - between petrous part of temporal bone and basilar part of occipital bone (inferior petrosal sulcus)
Drains from - cavernous sinus
Drains to - sigmoid sinus
84
Transverse sinus site and drainage
Site - transverse sulcus of occipital bone
Drains from - confluence of sinuses
Drains to - sigmoid sinus
85
Sigmoid sinus site and drainage
Site - Sigmoid sulcus
Drains from - superior and inferior petrosal sinus and transverse sinus
Drains to - internal jugular vein
86
87
88
Nerve supply of tongue sensory and taste
Posterior 1/3 - general + taste - glossopharyngeal
Anterior 2/3 - general - lingual nerve. Taste - chorda tympani
89
Extrinsic muscles of tongue
Styloglossus
Hyoglossus
Palatoglossus
Genioglossus
90
Which muscle retracts the tongue
Styloglossus
91
Nerve supply of muscles of tongue
Hypoglossal nerve all except palatoglossus - vagus
92
What does this lymph node biopsy show from pre auricular lymph nodes
H&E stain
Brown pigmented cells - melanocytes
Metastasis from malignant melanoma
93
What are the regions drained by preauricular LNs
Upper half of the face
Temporal region
Auricle and EAM
Gums
94
Posterior triangle of neck boundaries
Base - middle 1/3 of clavicle
Anterior - posterior border of SCM
Posterior - anterior border of trapezius
95
Anterior triangle boundaries
Anterior - midline of neck
Posterior - ant border of SCM
Superior - lower border of mandible
96
Subdivisions of anterior triangle of neck and what subdivides them
Digastric muscle and superior belly of omohyoid
Carotid triangle
Muscular triangle
Submandibular triangle
Submental triangle (half)
97
Identify the surface marking of spinal root of accessory nerve
Line drawn between the junction of upper 1/3 and lower 2/3 of SCM and junction between upper 2/3 and lower 1/3 of trapezius
98
Muscles supplied by spinal accessory nerve
SCM and trapezius
99
1, 2, 8, 11, 16, 19, 43, 48, 54
2 - anterior belly of digastric
48 - posterior belly of digastric
54 - superior belly of omohyoid
8 - common carotid artery
11 - external carotid artery
19 - hypoglossal nerve
1 - spinal accessory nerve
43 - cut SCM
16 - great auricular nerve
100
What is the root and supply of great auricular nerve
C2,3
Angle of mandible
Skin over parotid
Lower half of auricle
101
Where does the common carotid artery bifurcate
Upper border of thyroid cartilage - C4
102
Where does ECA end
behind neck of mandible in the substance of the parotid by dividing into maxillary and superficial temporal arteries
103
Branches of ECA
1. Superior thyroid artery
2. lingual artery
3. facial artery
4. ascending pharyngeal
5. occipital artery
terminal branches - maxillary and superficial temporal
104
Where is the carotid body
On posterior aspect of bifurcation of common carotid artery
105
Function of carotid body
Contains baroreceptors sensitive to pressure changes in the artery
106
Nerve supply of carotid body
Carotid sinus nerve branch of glossopharyngeal nerve
107
Where to palpate the facial artery
Where it crosses the inferior border of the mandible immediately adjacent to the anterior margin of masseter muscle
108
What happens if you ligate the facial artery during surgery
There will be colateral circulation from rich anastomosis between facial and maxillary arteries
109
What is the surface marking of the parotid gland
110
Demonstrate the parotid duct
111
Where does the parotid duct open
pierces buccinator opposite second upper molar tooth
112
Blood supply and drainage of parotid
ECA while it runs through its substance
Retromandibular vein
113
What forms retromandibular vein
Union of maxillary and superficial temporal veins
114
What is the parasympathetic ganglion supplying parotid
Otic ganglion
Passes through foramen ovale
115
What is the pathway of the parasympathetic supply to parotid
Starts in superior salivary nucleus
Travels with glossopharyngeal nerve, tympanic nerve then lesser petrosal nerve to otic ganglion
Then via the auriculotemporal nerve to the parotid
116
Which structures pass through parotid gland
Facial nerve and its branches
Retromandibular vein
External carotid artery and its two terminal branches
Auriculotemporal nerve
Deep parotid lymph nodes
117
What type of secretions of parotid gland
Serous
118
What is the ddx of a parotid lump
- infection (parotitis or mumps)
- obstructed duct (external compression or calculus)
- neoplasm (benign or malignant)
- deep parotid lymphadenopathy
119
Frey syndrome
Auriculotemporal nerve supplies parasympathetic supply to parotid and sympathetic supply to sweat glands to skin over parotid
After injury, faulty regeneration can occur, some of the parasympathetic fibres will enter the sweat glands of the skin
Sweating and dermal flushing from salivary stimulus
120
Lymphatic drainage of parotid
Superficial and deep parotid lymph nodes
121
Which cranial nerves contain parasympathetic function
Oculomotor
Facial
Glossopharyngeal
Vagus
122
Submandibular gland type of secretion
mucous and serous
123
Where does the submandibular duct open
The floor of the mouth on either side of lingual frenulum called sublingual papilla
124
Nerves at risk of injury on submandibular gland excision
Marginal mandibular branch of facial nerve
Lingual nerve
Hypoglossal nerve
125
How to avoid damage to marginal mandibular branch of facial nerve during submandibular gland excision
Incision should be made 4cm inferior to mandible
126
What are the muscles of mastication
Masseter
Temporalis
Medial pterygoid
Lateral pterygoid
127
Action of muscles of mastication and nerve supply
Masseter elevates mandible
Temporalis elevates and retracts
Medial pterygoid - elevation and side to side
Lateral pterygoid - depression, protrusion and side to side
Mandibular branch of trigeminal nerve
128
129
What does this MRA show and what clinical symptoms
Right middle cerebral artery occlusion - no contrast distal
Left sided facial hemiplegia, upper and lower limb hemiplegia
Aphasia if this is the dominant hemisphere
130
What is this and what is the clinical consequence
MCA aneurysm on right side
If ruptures will cause SAH
131
What are the cortical branches of middle cerebral artery
Branches from stem:
- Orbitofrontal artery
- Anterior temporal artery
Branches from upper division:
- Prefrontal artery
- Precentral
- Central
- Post central
- Parietal (anterior and posterior)
Branches from lower division:
- Middle temporal
- Temporooccipital
- Angular
132
133
Identify the parietooccipital sulcus
134
Describe the course of internal carotid artery
Cervical part arises from CCA at upper border of thyroid cartilage at C4
Enters the cranial cavity with the sympathetic plexus through the carotid canal and becomes the petrous part of ICA
Emerges through foramen lacerum and becomes the cavernous part of ICA
It lies on the carotid groove of the sphenoid bone in the cavernous sinus
Emerges from cavernous sinus below anterior clinoid process and becomes cerebral part
Makes a 100 deg turn to give MCA and ACA as terminal branches
135
Course of the vertebral artery
Emerges from the foramen transversum of C1
Arch along the posterior arch of C1 and enter foramen magnum
Passes upwards, forwards and medially in the sub arachnoid space
Reach the anterior aspect of medulla
Joins contralateral vertebral at the lower border of the pons to become basilar
136
What do the vertebrobasilar arteries supply in the brain
All of brainstem
Occipital lobe
Cerebellum
Thalamus
137
Relations of the middle ear
Floor - internal jugular vein
Roof - temporal lobe of brain (above tegmen typmani)
Anterior - internal carotid artery and sympathetic plexus
Posterior - mastoid air cells
Medial - inner ear
Lateral - Tympanic membrane
138
4, 9, 8, 15, 19
9 - cerebellum
8 - cerebellar tonsil
15 - 4th ventricle
19 - thalamus (3rd ventricle will be medial to this)
4 - aqueduct of sylvius
139
Identify subarachnoid cisterns
1 - cisterna magna
2 - prepontine cistern
3 - interpeduncular cistern
4 - suprasellar cistern
5 - lilequist membrane
140
What is the circulation of the csf
Formed in lateral ventricle
Through foramen of Monroe to 3rd ventricle
Through aqueduct of sylvius to 4th ventricle
Through foramen of magendie (medial) and lushka (lateral) to subarachnoid space
Then to arachnoid villi and superior sagittal sinus
141
What is shown in this MRI
Herniation of the cerebellar tonsil through the foramen of magnesia via the cisterna magna
This results in non communicating/obstructing hydrocephalus
Arnold Chiari malformation
142
What does this MRI show
What structure does it compress
What area of the brain is affected
What are the symptoms
Meningioma - closely related to superior sagittal sinus
Parasagittal meningioma
If it enlarges it will compress superior sagittal sinus
Area 4 - primary motor cortex
Monoparesis of the contralateral lower limb
143
Where is the location of the motor area 4
Describe its topographical organisation
Precentral gyrus
Homonculus of the opposite body half with the head most laterally and the legs and feet most medially
Disproportionate representation of the body parts - hand and face are largest
144
Where is motor area 6 and what is its functoin
Anterior to area 4
Divided in 2
- premotor area - anticipation and planning of movements based on sensory stimuli
- supplementary motor area - anticipation and planning based on memory
145
What does this MRI show
Gadolinium enhanced MRI
Ring enhancing lesion - due to breakdown of bbb and development of inflammatory capsule
DDX -
Metastasis
Abscess
Glioblastoma (most likely)
Infarct
Contusion
Demyelinating disease
Radiation necrosis or resolving haematoma
146
3, 5,9,19, 23, 24, 28, 35, 36, 37
24 - optic nerve
23 - optic chiasm
19 - oculomotor nerve
5 - tentorium cerebelli attached border
9 - free border of tentorium cerebelli
36 - tentorium cerebelli
37 - posterior attachment of tentorium cerebelli (transverse sulcus)
35 - lateral attachment of tentorium cerebelli
3 - anterior crinoid process
28- posterior crinoid process
147
What is the significance of the proximity of the oculomotor nerve to the free border of tentorium cerebelli
In increased ICP the oculomotor nerve will be compressed at this location
148
Which muscles does oculomotor nerve supply
All extra ocular muscles except superior oblique (4) and lateral rectus (6)
149
What happens in oculomotor palsy
The eye is displaced down and out
Ptosis
Dilation of pupil
Unopposed action of LR and SO
Paralysed levator palpebrae superioris
Paralysed sphincter pupillae muscle
150
What is the tentorium cerebelli
Meningeal dural fold separating the cerebellum from the posterior part of the cerebellar hemisphere
151
Attachments of tentorium cerebelli
Posterior - transverse sulcus of occipital bone
Lateral - superior border of petrous part of temporal bone
Medial - anterior part is free, posterior part is attached to anterior and posterior clinoid processes
Free borders form the tentorial notch through which midbrain passes
152
What is a false localising sign
Neurological signs which reflect dysfunction distant from expected anatomical location of the pathology
e.g abducent nerve palsy due to increased ICP - contralateral nerve compression
153
