Head And Neck Flashcards
1
Q
What does the neurocranium do?
A
Completely encloses the brain
2
Q
What does the viscerocranium do?
A
Produces the face
3
Q
Where do cranial nerves leave the skull in order to innervate the face?
A
The front of the skull
4
Q
Where do cranial nerves leave the skull in order to innervate the neck and below?
A
Back of the skull
5
Q
What are the margins of the anterior triangle of the neck?
A
Inferior margin of mandible
Midline of neck
Anterior margin of sternocleidomastoid
6
Q
What structures are associated with the anterior triangle of the neck?
A
Structures crossing between the head and thorax
7
Q
What are the margins of the posterior triangle of the neck?
A
Posterior margin of sternocleidomastoid
Anterior margin of trapezius
Clavicle
8
Q
What structures are associated with the posterior triangle of the neck?
A
Structures crossing between the thorax/neck and upper limb
9
Q
List 3 sites where 3 bones of the skull are fused
A
Bregma, pterion, lambda
10
Q
What is the lymphatic system comprised of?
A
Fluid (lymph)
Drainage vessels
Lymphatic tissues - nodes/lymphoid organ
11
Q
How is tissue fluid formed?
A
Net filtration of fluid does not equal net reabsorption of fluid.
Tissue fluid in interstitium enters lymphatic capillaries, forming lymph
12
Q
What does lymph fluid consist of?
A
Tissue fluid, small proteins, lipids (chylomicrons from gut lymphatics), damaged cells, bacteria, cancer cells
13
Q
Approximately how much lymphatic fluid is produced per day?
A
~3-4 litres
14
Q
How is lymphatic drainage unidirectional?
A
Valves. Passive constriction (pulsation of artery/muscle contraction). Intrinsic constriction
15
Q
Describe the order of lymphatic flow
A
Tissue fluid, lymphatic capillary, lymphatic vessels (afferent), lymph nodes, lymphatic vessels (efferent), lymphatic trunks, lymphatic ducts
16
Q
Where does the majority of lymph fluid drain into ultimately?
A
2 main lymphatic ducts which drain into subclavian veins
17
Q
What lymph drains into the right lymphatic duct?
A
Right upper quadrant (arm, chest and side of head)
18
Q
What lymph drains into the left thoracic duct?
A
Both legs, 1\2 of head, arm
19
Q
What is lymphoedema?
A
Abnormal collection of protein rich fluid causing tissue to swell due to compromised lymphatic system
20
Q
What might cause lymphoedema?
A
Removal or enlargement of lymph nodes
Infections (e.g. Certain proteins)
Damage to lymphatic system e.g. Cancer treatments
Lack of limb movement (albeit not alone! Muscle contraction assists movement of lymph)
Congenital e.g. Milroys syndrome
21
Q
List the lymphatic organs
A
Spleen, thymus, tonsils, lymph nodes
22
Q
Describe the constitution of a lymph node
A
Connective tissue structures - tough fibrous outer capsule. Reticular connective tissue inside ‘candy floss’
23
Q
What cells do lymph nodes contain?
A
Large collections of lymphocytes (B and T) and macrophages
24
Q
How does the lymph system help defence against infection?
A
All substances transported in lymph pass through at least 1 lymph node.
Physical filter
Phagocytic filter
Full of lymphocytes, active and proliferate in response to antigens
25
What is lymphadenopathy?
Swollen lymph nodes. Very common patient presentation.
26
What is the difference between in presentation of infective and malignant lymphadenopathy?
Infective - tender, mobile (most common)
| Malignant - hard, matted, non-tender
27
What should you do on a patient presenting with lymphadenopathy?
Comprehensive history, examine area of tissue it drains, if malignancy suspected examine other lymph nodes and body systems
28
How can lymph nodes be classified?
Regional - drain specific areas (superficial, more readily palpable)
Terminal - receive drainage from number of regional nodes (deep)
29
What separates superficial (regional) and deep (terminal) lymph nodes?
Investing layer of deep cervical fascia of the neck
30
What is Waldeyer's ring?
Annular collection of lymphatic tissue (nodules) surrounding superior pharynx. Consists of 'tonsils' - pharyngeal tonsil (adenoids), palatine tonsil X2, lingual tonsil X2
31
Why is it important to check the supraclavicular lymph nodes?
Abdominal/thoracic malignancies can present as enlarged supraclavicular nodes. Oversee transport of lymph from thoracic cavity and abdomen
Left: virchows node, abdomen and thorax
Right: midsection chest, oesophagus and lungs
32
Where does head and neck superficial lymph nodes drain into?
Deep cervical lymph nodes which surround the IJV before then draining via thoracic duct into subclavian vein
33
Where does lymph drain into the jugulo-digastric node?
Palatine tonsils, oral cavity, posterior 1/3 tongue, pharynx, larynx
34
Name the major blood vessels of the head and neck
External jugular, internal jugular, common carotid
35
Does the common carotid artery give off any branches in the neck?
No
36
What happens to the common carotid artery?
Bifurcates to give the external and internal carotid arteries
37
Where do the vertebral, internal thoracic and thyrocervical arteries all arise from?
The subclavian artery in the base of the neck
38
On the right, what do the subclavian and common carotid arteries arise from?
The brachiocephalic trunk
39
Where do vertebral arteries arise from?
Subclavian arteries
40
Via where in the neck do the vertebral arteries ascend?
Ascend through the transverse foramina in cervical vertebrae 6 to 1
41
What arteries supply the brain?
Vertebral arteries, along with internal carotid arteries, enter skull through carotid canal
42
At approximately what level does the common carotid artery bifurcate?
Approximately level of the superior border of the thyroid cartilage
43
Where does the internal jugular artery lie?
Lateral to the common carotid, mostly under sternocleidomastoid
44
What is the carotid sinus?
A swelling at region of bifurcation. Location of baroreceptors for detecting changes in arterial BP
45
What is the carotid body?
Peripheral chemoreceptors which detect arterial pO2
46
What is the carotid sheath?
The common carotid artery and internal jugular vein lie within the carotid sheath along with the vagus nerve and deep cervical lymph nodes. The carotid sheath is closely related to the pretracheal, prevertebral and investing layers of deep fascia
47
What are the contents of the carotid triangle?
Internal jugular vein, bifurcation of common carotid (thus external and internal carotid arteries)
48
What are the boundaries of the carotid triangle?
Superior - posterior belly of digastric
Lateral - sternocleidomastoid
Medial - superior belly of omohyoid
49
What is the carotid triangle important for?
The surgical approach to the carotid arteries, or internal jugular vein. Can also access vagus and hypoglossal nerves.
Can feel the carotid pulse (may also be palpate inferiorly)
Carotid sinus massage
50
What might a carotid sinus massage be used to treat?
Possible treatment for supraventricular tachycardia (location of baroreceptors)
51
What are the 6 branches of the external carotid artery?
```
Superior thyroid
Lingual
Facial
Ascending pharyngeal
Occipital
Posterior auricular
```
52
What are the terminal branches of the external carotid artery?
Superficial temporal
| Maxillary
53
What are the major vessels supplying the scalp?
The internal/ophthalmic artery
| The external carotid artery
54
What vessels supply the scalp from the internal/ophthalmic artery?
Supra-orbital artery
| Supratrochlear artery
55
What vessels supply the scalp from the external carotid artery?
Superficial temporal artery
Posterior auricular artery
Occipital artery
56
What does the scalp consist of?
Skin, dense connective tissue, aponeurosis, loose connective tissue, periosteum
57
Briefly outline the blood supply to the scalp
Rich blood supply with many aponeuroses. Largely branches of external carotid artery, except supratrochlear and supraorbital arteries (branches of ophthalmic artery) which arise from the internal carotid artery.
58
Describe the structure of the blood supply to the scalp, and why this can lead to perfuse bleeding
```
Walls of arteries closely attached to connective tissue, limits constriction (can get perfuse bleeding)
Numerous anastomoses (can get perfuse bleeding)
Deep lacerations involving epicranial aponeurosis cause perfuse bleeding because of opposing pull of occiptfrontalis
```
59
What mostly supplies blood to the skull? What is a consequence of this?
Mostly the middle meningeal artery (thus loss of scalp does not lead to bone necrosis)
60
Broadly outline the structure of the blood supply to the scalp
Superficial veins generally accompany arteries (superficial temporal veins, occipital veins, posterior auricular veins)
61
Describe the venous drainage of the scalp
Supraorbital and supratrochlear veins unite at medial angle of eye to form angular vein, which drains into the facial vein. Some deep parts of the scalp in temporal region have veins which drain into the pterygoid venous plexus
62
Describe the connection between venous drainage of the scalp and curls venous sinuses (possible infection pathway)
Veins of scalp connect to diploic veins of skull through several emissary veins and thus to Duran venous sinuses. Emissary veins are valveless. Infection from scalp can spread to the cranial cavity and affect meninges.
63
What supplies the double layer of dura mater covering the brain?
Anterior/middle meningeal arteries
64
What might a fracture at the pterion cause?
MMA, middle meningeal artery, rupture. Supplies skull and dura. Extradural haemorrhage.
65
Why might a craniotomy be carried out? How?
To gain access to the cranial cavity. Bone and scalp are reflected inferiorly to preserve blood supply.
66
From were do all superficial arteries of the face arise from?
Arise from external carotid artery, apart from supra-orbital and supratrochlear, which are from internal carotid artery (via opthalamic)
67
Describe the endothelium rural venous sinuses
Lined spaces between periosteal and meningeal layers of dura. Form at dural septae. Receive blood from large veins draining blood from brain.
68
Describe sigmoid dural venous sinuses
Continue as the internal jugular veins, leaving the skull through the jugular foramena
69
What is the cavernous sinus?
A plexus of extremely thin walled veins on upper surface of sphenoid
70
What, other than the cavernous sinus veins, is in the cavernous sinus?
```
Internal carotid artery
CN III occulomotor
CNIV trocholear
CN VI abducent
2 branches of trigeminal (CN 1 ophthalmic and CN 2 maxillary)
```
71
Describe the connection of the facial veins with cavernous sinus and pterygoid venous plexus
Veins of the face are valveless. At medial angle of eye, facial vein communicates with superior ophthalmic - drains into cavernous sinus.
Deep facial veins drain into pterygoid venous plexus. Infection from facial vein can spread to dural venous sinuses. Infected clot can travel to intercranial venous system
72
How many pairs of cranial nerves are there?
12
73
What do the cranial nerves supply?
Structures of the head and neck (+ vagus, which supplies structures in thorax and abdomen also)
74
What types of nerve may cranial nerves be?
General sensory, special sensory, motor or autonomic
75
What is the brainstem?
Adjourns the brain to the spinal cord. Continuous with spinal cord caudally.Ascending and descending fibres between brain and rest of body run through it. Location of the majority of cranial nerve nuclei
76
What does the brainstem do?
Vital role in regulation of cardio-respiratory functions and maintaining consciousness. Ascending and descending fibres between brain and rest of body run through it.
77
Where are th majority of cranial nerve nuclei located?
In the brainstem
78
What are the cranial nerve nuclei, as found in the brainstem?
Collections of cell bodies of nerve fibres that make up the whole cranial nerve
79
What constitutes the brainstem?
Midbrain, pons and medulla
80
What is cranial nerve 1 called?
Olfactory nerve
81
What does cranial nerve 1 sense?
Special sensation - smell
82
How would you test cranial nerve 1?
Test one nostril at a time, smelling salts.
83
Describe cranial nerve 1
Paired anterior extensions of forebrain, rather than a 'true' cranial nerve.
84
Other than a URTI, what else is a common cause of anosmia (loss of sense of smell)?
Head injury- shearing forces/basilar skull fracture (nerve endings poke through cribform plate)
85
What is cranial nerve 2 called?
Optic nerve
86
Describe the route of the optic nerve CN 2
Retina, optic canal, optic chiasm, optic tracts
87
What does the optic nerve CN2 sense?
Special sensation, vision
88
How would you test the optic nerve CN2?
Test one eye at a time. Visual tests and pupils
89
How might you be able to see the optic nerve?
Seen directly with fundoscopy 'optic disc'
90
What is cranial nerve 3 called?
Oculomotor nerve
91
Describe the route of the oculomotor nerve CN3
Route - SOF (superior orbital fissure) - orbit
92
What cranial nerves originate in the forebrain?
CN 1 and 2
| Olfactory and optic nerves
93
What nerves originate in the midbrain?
CN 3 and 4
| Oculomotor and trochlear nerves
94
What type of sensation does the oculomotor CN3 sense?
Motor/autonomic (parasympathetic)
95
What muscles does CN3 oculomotor innervate?
4/6 ocular muscles
96
How would you test the function of the oculomotor CN3 nerve?
Inspection of eyelid and pupils. Eye movements. Pupillary light reflexes
97
How might a person with CN3 oculomotor nerve lesion present?
Present with diplopia (double vision). Eye in 'down and out' position with severe ptosis +/- pupillary dilation.
98
What might cause a CN3 oculomotor nerve lesion?
Raised intercranial pressure (tumour/haemorrhage), aneurysm (posterior communicating artery), cavernous sinus thrombosis. Diabetes/hypertension (pupil sparing).
99
What is the cavernous sinus?
Split between the dura and other membranes. Dura lined cavity containing many veins, nerves and internal carotid artery.
100
What is CN4 called?
Trochlear nerve
101
What is key about the route of CN4 trochlear nerve
The longest intracranial route of all CNs. Only CN to arise from dorsal aspect of the brainstem.
102
What type of sensation does the CN4 trochlear nerve transmit?
Motor to extra ocular muscles only
103
How would you test CN4 trochlear nerve?
Eye movements
104
How might a CN4 trochlear nerve lesion present?
Rare and subtle, often can correct with slight tilt of head. Diplopia, worse on downward gaze e.g. When reading, walking downstairs.
105
What might commonly cause a CN4 trochlear nerve lesion?
Head injury, or any cause of raised intercranial pressure. Congenital palsies (children)
106
What is CN5 called?
Trigeminal nerve
107
Describe the route of the CN5 trigeminal nerve
Pons - superior orbital fissure - foramen rotundum - foramen ovale
108
What sort of innervation does the CN5 trigeminal nerve do?
Motor/sensory
Muscles of mastication
Main sensory nerve of face
109
How would you test the trigeminal CN5 nerve?
Test sensation to face
| Test muscles of mastication
110
What is neuralgia ?
Intense pain to light touch
111
Which cranial nerves originate in the pons?
CN 5,6,7 and 8
| Trigeminal, abducens, facial and vestibulocochlear
112
What is CN6 called?
Abducens nerve
113
What route does the abducens nerve CN6 take?
Pons - superior orbital fissure
114
What sort of innervation does the abducens nerve do?
Motor, to one muscle (lateral vectus)
115
How do you test the function of abducens CN6?
Eye movements
116
In what circumstances is abducens nerve CN6 susceptible to injury?
Raised intercranial pressure, e.g. Due to bleed/tumour
117
How would a patients with a CN6 abducens nerve lesion present?
Diplopia
118
What is CN7 called?
Facial nerve
119
Describe the route of CN7 facial nerve
Pons - internal acoustic miatus - petrous temporal bone - stylomastoid foramen
120
What sort of innervation does CN7 facial nerve do?
Motor/sensory/autonomic
Muscles of facial expression.
Taste (anterior 2/3 of tongue)
Parasympathetic to lacrimal and salivary glands
121
How might you test the function of CN7 facial nerve?
Test muscles of facial expression
| Taste not formally used often
122
What is 'bells palsy'
Facial nerve palsy
123
What might cause facial nerve 'bells' palsy?
Parotid tumours
124
What nerve has the facial nerve got a close relationship with?
Vestibulocochlear nerve
125
What is CN8 called?
Vestibulocochlear nerve
126
Describe the route of the vestibulocochlear nerve CN8
Pons - internal acoustic miatus
127
What sort of innervation does the vestibulocochlear nerve CN8 do?
Special sensory (hearing/balance)
128
How would you test the vestibulocochlear nerve CN8?
Hearing
| Rinne's and Weber's tests
129
How might a patient with vestibulocochlear nerve CN8 lesion present?
Hearing loss. Vertigo/tinnitus, acoustic neuroma (benign tumour)
130
What is CN9 called?
Glossopharyngeal nerve
131
Describe the route of CN9 glossopharyngeal nerve
Medulla - jugular foramen
132
What nerves originate in the medulla?
CN 9, 10, 11, 12
| Glossopharyngeal, vagus, spinal accessory, hypoglossal nerves
133
What type of innervation does the glossopharyngeal CN9 nerve do?
Special sensory - taste posterior 1/3 of tongue
General sensory - soft palate, tonsils, oropharynx, tympanic membrane. Carotid body and sinus
Autonomic - parotid gland
Motor - 1 muscle, stylopharyngeus
Mostly sensory!
134
How would you test CN9 glossopharyngeal nerve?
```
Gag reflex (sensory limb), taste not often formally tested
Tested in conjunction with CNX
```
135
What is CN 10 called?
Vagus nerve
136
Describe the route of CNX vagus nerve
Medulla - jugular foramen - carotid sheath - neck
137
What sort of innovation does the vagus nerve do?
General sensory - laryngopharynx, larynx mainly (also small part of ear
Motor - muscles of soft palate, pharynx, larynx
Autonomic - parasympathetic to thoracic and abdominal viscera
(Special sensory)
138
How would you test the vagus nerve CNX?
Noting speech, swallow, cough, gag reflex (efferent limb)
139
What is a common sign if there is an isolated lesion of CNX vagus nerve?
Deviation of uvula when soft palate elevated.
| Injury to recurrent laryngeal nerve branch can cause hoarseness and dysphonia
140
What is CN 11 called?
Spinal accessory nerve
141
Describe the route of the accessory CNXI nerve
Medulla - jugular foramen
142
What sort of innervation does the spinal accessory CNXI nerve do?
Motor - sternocleidomastoid, trapezius
143
How would you test the spinal accessory nerve CNXI?
Shrug shoulders, turn head against resistance
144
When would the spinal accessory nerve CN11 be susceptible to injuries?
Runs down through neck in posterior triangle. Susceptible to injury here e.g. Lymph node biopsies, stab wound
145
What else contributes to the spinal accessory nerve, other that's the cranial root?
Receives spinal rootlets from upper 5/6 cervical segments. Ascend up foramen magnum to join cranial root.
146
What is CN12 called?
Hypoglossal nerve
147
Describe the route of CN 12 hypoglossal nerve
Medulla - hypoglossal canal
148
What sort of innervation does the hypoglossal CN 12 nerve do?
Motor only
| Muscles of the tongue
149
How would you test function of CN 12 hypoglossal nerve?
Inspection or movement of tongue
150
How would nerve lesion to CN12 present?
Damage to CN12 causes weakness and atrophy of the tongue muscles on ipsilateral side
151
What cranial number is the hypoglossal nerve?
CN XII
| CN 12
152
What cranial number is the spinal accessory nerve?
CN XI
| CN 11
153
What cranial number is the vagus nerve?
CN X
| CN 10
154
What cranial number is the glossopharyngeal nerve?
CN IX
| CN 9
155
What cranial number is the vestibulocochlear nerve?
CN VIII
| CN 8
156
What cranial number is the facial nerve?
CN VII
| CN 7
157
What cranial number is the abducens nerve?
CN VI
| CN 6
158
What cranial number is the trigeminal nerve?
CN V
| CN 5
159
What cranial number is the trochlear nerve?
CN IV
| CN 4
160
What cranial number is the oculomotor nerve?
CN III
| CN 3
161
What cranial number is the optic nerve?
CN II
| CN 2
162
What cranial number is the olfactory nerve?
CN I
| CN 1
163
What is the autonomic nervous system a part of?
The peripheral nervous system
164
Where is the central control of the autonomic nervous system?
The hypothalamus
165
What does the autonomic nervous system control?
Body functions not under conscious control
| Maintains and fine tunes internal environment, accelerator and brake.
166
Describe the layout of the autonomic nervous system
Preganagloinic neurone, ganglion, postgangloinic neurone
167
What might the target tissues for the autonomic nervous system be?
Smooth muscle, cardiac muscle, glands
168
What might also be called 'visceral efferent/motor'?
The autonomic nervous system
169
Where do the sympathetic nerves arise from?
The thoracolumbar spinal cord T1 to L2
170
Where do the parasympathetic nerves arise from?
The brainstem
171
What does the sympathetic autonomic nervous system innervate? (4 tings)
Smooth muscle of blood vessels, eye lid (tarsal muscle) and iris (dilator pupillae)
Sweat glands
Arrector pili muscles (hair follicles)
DECREASES secretions from salivary and lacrimal glands
172
What does the parasympathetic autonomic nervous system innervate? (3 tings)
```
Smooth muscle of iris (sphincter pulillae) and ciliary body (controls thickness of lens)
Lacrimal glands (tears)
Salivary and mucosal glands
```
173
Describe the chain via which the sympathetic nerves innervating the head and neck get there
```
Arise from spinal cord
Sympathetic chain
Cervical ganglion
Hitch hike onto blood vessels (carotid plexus)
Target tissues
```
174
What smooth muscle is innervate do by the sympathetic autonomic nervous system?
Smooth muscle in eyelid and iris (dilator)
Smooth muscle in blood vessel walls
Arrector pills muscles of hairs
Sweat glands
175
What are the carotid arteries and lung apex important anatomical relations to?
Sympathetic nerves innervating the head and neck
176
Pathology in the carotid arteries or lung apex may cause anatomical dysfunction where else?
In the eye and face
177
What is horners syndrome?
Mitosis, partial ptosis, +/- anhydrosis
Interruption of sympathetic nerve supply to head and neck. Possible diagnosis relate to anatomical relations of sympathetic nerve on its route from spinal cord to head (apex of lungs, carotid artery dissection)
178
What might cause horners syndrome? (Mitosis, partial ptosis, +/- anhydrosis)
Interruption of sympathetic nerve supply to head and neck. Possible diagnosis relate to anatomical relations of sympathetic nerve on its route from spinal cord to head (apex of lungs, carotid artery dissection)
179
What is the origin of the sympathetic nerves in the head and neck?
Spinal cord T1 to L2
| Mostly T1 and T2
180
What ganglia are a part of the sympathetic nervous system of the head and neck?
In cervical portion of sympathetic chain
Superior cervical ganglion
Middle cervical ganglion (structures in neck and chest)
181
Upon what do the sympathetic nerves of the head and neck hitchhike on?
Blood vessels
| Very distally join branches of CN 5
182
What are the effector tissues of the sympathetic nerves of the head and neck?
Eye (dilator pupillae)
Eye lid (superior tarsal muscle)
Smooth muscle
Sweat glands (+salivary and lacrimal glands DECREASING secretions)
183
Describe the response of the sympathetic nerves of the head and neck
'Fight or flight'
| Pupillary dilation, assists lid retraction, vasoconstriction, sweating
184
Describe the route taken by the parasympathetic nerves supplying the head and neck
```
Arise from brainstem
Hitchhike onto one of 4 CNS
Ganglion
Hitchhike onto branches of CN 5
Target tissue
```
185
List the 4 ganglions used by parasympathetic nerves supplying the head and neck
Edinger Westphal
Superior Salivary
Inferior Salivary
Dorsal Motor
186
What do the parasympathetic nerves in the head and neck innervate?
Smooth muscle of iris (constrictor) and ciliary body (controls lens)
Mucosal glands in nasal/oral mucosa/resp tract
Salivary and lacrimal glands
187
List some signs of parasympathetic CN 7 lesions
Pathology at of before geniculate ganglion may involve all parasympathetic functions carried out within CN7
Pathology after genticulate ganglion will not involve greater oetrosal nerve (lacrimal gland spared)
188
Describe the route taken by parasympathetic CN3 oculomotor
Brainstem (EWN) para. Fibres emerge with CN3 fibres
Hitchhike on CN3. Preganglionic
Ciliary ganglion. Post ganglioninc hitchhike on small branches from V1/Va
Eye ciliary body pupillae sphincter
189
Describe the route taken by the parasympathetic CN9 glossopharyngeal
```
Jugular foramen
Tympanic nerve
Tympanic plexus
Lesser petrosal nerve - Foramen ovale
Optic ganglion (in infratemporal space)
Branch of CN V3
Parotid gland
```
190
What does the parasympathetic CN 9 nerve do? (Parotid gland)
Motor to stylopharyngeus
Sensory from oropharynx, tonsils
Taste and general sensation (posterior 2/3 tongue)
Sensory branches to carotid body/sinuses
191
Describe the route of the parasympathetic CNX vagus nerve
```
Brainstem (medulla)
Hitchhike on CNX and its branches
Meets ganglion at/in target tissue
Either
Thorax and abdomen
Or
Glands in laryngopharynx, larynx, oesophagus and trachea
```
192
Upon what cranial nerves can parasympathetic nerves hitchhike on?
CNs 3, 7, 9 and 10
| BUT all post ganglionic fibres (except CNX) reach effector organs via branches of CN5
193
What ganglia do the parasympathetic head and neck nerves use?
Ciliary
Pterygopalatine
Submandibular
Otic
194
What are the effector tissues of the head and neck parasympathetic nerves?
```
Eye (sphincter pupillae and ciliary muscles)
Lacrimal glands
Muscosal glands
Salivary glands
Parotid gland
```
195
What is the response of the parasympathetic head and neck nerves?
'Rest and digest'
Constrict pupil
Accommodation reflex (lens shape)
Glandular secretions (decreases salivary secretions and lacrimal glands)
Cardiac muscle and smooth muscle in the gut
196
Describe the boundaries of the eye socket
```
Apex - optic canal
Superior - frontal and sephenoid
Lateral - zygomatic, sephenoid
Medial - ethmoid, maxillary, lacrimal, sphenoid
Inferior - maxillary, zygomatic
```
197
What are the 3 layers of eyeball anatomy?
Outer fibrous layer - sclera, cornea
Middle vascular layer - iris, ciliary body, choroid
Inner layer - lens, aqueous humour, vitreous humour, optic disc, macula/fovea, optic nerve
198
What surrounds the optic nerve?
Pia mata, arachnoid mata, and dura mata (outermost)
199
How is the fluid in the eye normally produced/get to eye?
Aqueous fluid produced by ciliary body. To anterior chamber. Flows out via trabecular mesh work
200
What's in the outmost layer of eyeball anatomy?
sclera, cornea
201
What's in the middle (vascular) layer of eyeball anatomy?
Iris, ciliary body, choroid
202
What's in the outermost layer of eyeball anatomy?
lens, aqueous humour, vitreous humour, optic disc, macula/fovea, optic nerve
203
How many muscles control the eye?
7
204
How many cranial nerves innervate the eye?
3
205
Describe the blood supply to the eye
From ICA
| Gives rise to retinal artery. Terminal branches
206
Describe the venous drainage of the eye
Central retinal vein. Drains to superior ophthalmic vein, which drains into the cavernous sinus
207
What is the function of the eyelid?
Protects against injury, excessive light, dryness
208
What gland does the eyelid contain?
Tarsal gland and ciliary glands
209
How does the eye open?
Levator palpabrae supefioris CN III
| Superior tarsal muscle (sympathetic)
210
What would cause complete ptosis?
CN III lesion
211
What would cause partial ptosis?
Sympathetic lesion
212
What is the ear the organ of?
Hearing and balance
213
List some possible symptoms of ear disease
Varied. Pain (otalgia), discharge, hearing loss (conductive Vs sensorineural), tinnitus, vertigo, facial palsy
214
What does the cochlea do?
Converts sound vibration into an electrical signal (action potential), which is perceived as sound
215
What part of the ear is involved wth maintaining sense of position and balance?
Vestibular apparatus
216
What is the inner ear?
Vestibular apparatus and cochlear
217
What might cause abnormalities of the pinna?
Trauma, inflammatory, congenital, infective
218
What is pinna haematoma?
Accumulation of blood between the cartilage and perichondrium. Deprives cartilage of blood. Pressure and supply necrosis. Secondary to blunt injury to pinna
219
What is a possible complication of untreated pinna haematoma?
Fibrosis and new asymmetrical cartilage development 'cauliflower ear'
220
In which direction do yo need to pull the ear in order to examine the tympanic membrane in adults?
Up and back
221
In which direction do yo need to pull the ear in order to examine the tympanic membrane in children?
Just back
222
What shape is the external acoustic meatus?
Sigmoid
223
What constitutes the external acoustic meatus?
Cartilaginous outer 1/3
| Bony part inner 2/3
224
Where are the hairs on the external acoustic meatus?
Cartilaginous part (outer 1/3)
225
What is the function of the hairs on the external acoustic meatus?
Prevent objects entering deeper into ear canal. Also aid in desquamation and skin migration out of canal
226
What is the function of the pharyngotympanic tube?
Equilibrates pressure within middle ear cavity with that of the atmosphere. Also important in ventilation of and drainage of mucus from the middle ear
227
By when does OME usually spontaneously clear?
2-3 months
228
What are some possible complications of OME?
Tympanic membrane perforation
Facial nerve involvement
Mastoiditis, intracranial complications (meningeal brain abscess, sigmoid sinus thrombosis)
229
What is mastoiditis?
Mastoid air cells communicate with middle ear cavity as they are involved in helping to equilibrate middle ear pressures. Provides a potential route for middle ear infections to spread into the mastoid bone (mastoid air cells)
230
Describe the relationship between the facial nerve and the middle ear
Facial nerve, in particular chords tympani branch, runs through the middle ear. Facial nerve may thus be involved in pathology involving the middle ear
231
What is cholesteatoma?
Usually secondary to chronic/recurring ear infections and blockage of ET. Creates a sucking negative pressure, drawing eardrum inwards. Can lead to small pocket farming
Skin cells trapped, collect and continue to grow in this small pocket within middle ear.
Not malignant, but grows slowly and expands, eroding into structures e.g. Ossicles, mastoid bone, cochlea
Ranges from painless otorrhea (ear discharge), to serious neurological complications .
232
What is the cochlea?
Our organ of hearing. A fluid filled tube. Movements at the oval window set up movements of the fluid in the cochlea. Waves of fluid cause movement of special sensory cells within the cochlear duct, which fire action potentials
233
How do we hear?...
Vibration of ossicles (stapes at the oval window) sets up vibrations/movement in cochlea fluid
Sensed by nerve cells in the cochlea duct (part of spiral organ of corti)
Movement of these receptors in organ of corti trigger action potential in CN8
Brain
234
Hat is the vestibular apparatus?
Includes the semicircular canals, the saccule and uticle - these are a fluid filled series of channels and sacs that respond to position and rotation, helping to maintain balance.
235
What is the function of the nose, nasal cavity and paranasal sinuses?
```
Sense of smell
Provide a route for inspired air
Filters inspired air (removing particles by trapping in nasal hair or mucus)
Moistens and warms inspired air
Resonating chamber for speech
```
236
What forma the medial wall of the nasal cavity?
The nasal septum (perpendicular plate of ethmoid bone, vomer bone, and septal cartilage)
237
What might cause a saddle nose haematoma?
Untreated septal haematoma
238
What results in a saddle nose deformity?
Cartilaginous part of septum takes its blood supply from overlying perichondrium. Trauma to nose can lead to buckling of septum and shearing of blood vessels. Blood accumulates between perichondrium and cartilage - septal haematoma. Untreated, leads to avascular necrosis of cartilaginous septum.
239
What is another risk of septal haematoma?
Development of an infection in the collecting haematoma - septal abscess. Formation further increases likelihood of avascular necrosis of septum.
240
What is the function of the olfactory mucous membrane?
Olfaction (smell)
241
What is the function of the respiratory mucous membrane, in the nose?
Pseudostratified columnar ciliates epithelium
Filters mucous/cilia
Humidifies (watery secretions)
Warms (rich blood supply)
242
What receives drainage from the paranasal sinuses and nasolacrimal duct?
Nasal cavity
243
What are nasal polyps?
Fleshy, benign swellings arising from nasal mucosa. Usually affect both sides of nasal cavity. Pale or yellow in appearance, or fleshy and reddened. Common in people over 40yrs
244
What are the symptoms of nasal polyps?
Blocked nose, and watery rhinorrhoea, post nasal drip, decreased smell and reduced taste.
Unilateral polyp +/- blood tinged secretion may suggest tumour.
245
What, with regards to nasal polyps, may be suggestive of a tumour?
Unilateral polyp +/- blood tinged secretion may suggest tumour.
246
What is rhinitis?
Inflammation of the nasal mucosal lining. Many causes, all lease to similar symptoms
247
What are the symptoms of rhinitis?
Nasal congestion, rhinorrhoea 'runny nose', sneezing, nasal irritation, post nasal drip.
248
List some common causes of nasal rhinitis
Simple acute infective rhinitis (viral, the common cold), allergic rhinits
249
Why does the nasal mucosa have a rich blood supply?
Key to allow for warming and humidification of inspired air in nasal cavity.
250
What is a drawback of having a rich blood supply to the nasal mucosa?
It's susceptible to injury! Bleeding
251
Describe the arterial supply of the medial and lateral walls of nasal cavity
Arise from branches of ophthalmic artery and branches of maxillary artery
Form a point of arterial anastomoses in anterior septum (kiesselbachs area)
Most common source of bleeding in epistaxis
252
What is the most common source of nasal bleeding?
In epistaxis
253
Describe the venous drainage of the nasal cavity
Into cavernous sinus, facial vein and pterygoid plexus
254
What are the paranasal sinuses?
Air filled spaces that are extensions of nasal cavity, rudimentary or absent at birth. Lined with respiratory mucosa (therefore ciliated and secrete mucous). Named according to bone in which they are found - 4 pairs. Help humidify and warm inspired air, reduce the weight of the skull. All drain into the nasal cavity via small channels called ostia, most into middle meatus.
255
How many paranasal sinuses are there?
4 pairs
256
What do the paranasal sinuses do?
Help humidify and warm inspired air, reduce the weight of the skull. All drain into the nasal cavity via small channels called ostia, most into middle meatus.
257
Where does the paranasal sinuses drain into?
All drain into the nasal cavity via small channels called ostia, most into middle meatus.
258
What is sinusitis?
Infections in nasal cavity that involve the sinuses
259
Which sinus is most commonly infected?
Maxillary
260
What is acute sinusitis?
An acute infection of lining of sinus lasting approx 4wks. Commonly infective and often secondary to viral infection of nasal cavity.
261
How is a diagnosis of acute sinusitis usually made?
Based on history and examination - non-resolving cold or flu like illness, pyrexia, rhinorrhoea +/- green/yellow discharge, headache/facial pain (in area of affected sinus), worse on leaning forwards, blocked nose
262
What are the symptoms of acute sinusitis?
non-resolving cold or flu like illness, pyrexia, rhinorrhoea +/- green/yellow discharge, headache/facial pain (in area of affected sinus), worse on leaning forwards, blocked nose
263
What increases the risk of sinusitis?
Conditions which may block ostia of sinuses e.g. Nasal polyps, deviated septum, dental infection (usually of upper teeth)
264
What can a primary nasal infection (e.g. Rhinitis) lead to?
Reduced ciliary function, oedema of nasal mucosa and sinus Ostia, and reduced nasal secretions. Drainage from sinus impaired. Stagnant secretions within the sinus become ideal breeding ground for bacteria - secondary infection (commonly strep haemophilus)
265
What is the treatment for acute sinusitis?
Symptomatic treatment e.g. Nasal decongestants, painkillers. Antibiotics only for severe or prolonged episodes
266
What nerve supplies the antero-superior portion of the nasal cavity (and most of the paranasal sinuses)?
Ophthalmic nerve (CNVa)
267
What supplies the postero-inferior portion of the nasal cavity (including maxillary sinus)?
Maxillary nerve (CNVb)
268
What are the boundaries of the oral cavity?
```
Roof - hard palate and soft palate
Floor - tongue and other soft tissues
Lateral walls - cheek
Anterior - oral fissure
Posterior - oropharyngeal isthmus
```
269
What is the oral vestibule?
Space between teeth and cheeks/lips
270
What is the oral cavity proper?
From the teeth to the ring made by the palatopharyngeal arch, the uvula, and the tip of the epiglottis
271
What is the posterior arch also called?
Palatopharyngeal arch
272
What is the anterior arch also called?
Palatoglossal arch
273
What forms the hard palate?
The maxilla and the palatine bones (the same as the bones that form the floor of the nasal cavity)
274
What forms the soft palate?
Muscular - palatoglossus and palatopharyngeus help form the anterior and posterior arches
Palatoglossus - palatoglossal (anterior) arch
Palatopharyngeus - palatopharyngeal (posterior) arch
275
Describe how the palatoglossus and palatopharyngeus help during swallowing and yawning
Tense and elevate soft palate
276
Describe the innervation of the soft palate
Predominantly vagus nerve - pharyngeal branch.
277
What way will the uvula deviate if one side of the vagus nerve is damaged?
If damaged, the stronger side is unopposed. Therefore pulls the uvula away from the side of the affected nerve
278
Why is the gag reflex important?
Important for preventing choking
279
Describe the afferent limb of the gag reflex
Glossopharyngeal. Back of tongue/threat, uvula, tonsillar area
280
Describe the efferent limb of the gag reflex
Vagus. Pharyngeal muscles of soft palate
281
Describe the sensory supply to the lower jaw
Supply from the inferior alveolar nerve - branch of CNV3. Can lose sensation during mandibular fracture. Site of anaesthesia use in dental surgery.
282
List the extrinsic muscles of the tongue
Styloglossus
Hypoglossus
Genioglossus
Palatoglossus (vagus nerve innervated)
283
List the intrinsic muscles of the tongue
Superior longitudinal
Vertical
Transverse
Inferior longitudinal
284
What do the extrinsic muscles of the tongue do?
Help anchor the tongue to hyoid and mandible bones. Allow tongue to change position
285
What do the intrinsic muscles of the tongue do?
Help tongue to change shape. Action based on the direction the fibres run in
286
Descibe the appearance of an injury to the tongue
The unaffected side dominates. Normal tongue muscle overpowers weakened muscle on affected side therefore, uvula deviation away from the side of lesion, and tongue deviation towards side of the lesion
287
Describe the uvula deviation in a tongue nerve injury
uvula deviation away from the side of lesion
288
Describe the tongue deviation in a tongue nerve injury
tongue deviation towards side of the lesion
289
What is the duct via which the parotid gland enters the oral cavity called?
Stensons duct
290
What is the duct via which the submandibular gland enters the oral cavity called?
Whartons duct
291
How does the sublingual gland enter the oral cavity?
Via multiple ducts
292
Describe the composition of salivary gland stones
Usually calcium based (saliva can crystallise and block salivary ducts)
293
What duct is most commonly effected by salivary gland stones?
Most commonly the submandibular duct - produces salivary that is comparatively thicker than parotid gland
294
What is the common presentation of salivary gland stones?
Commonly present as pain or swelling of the affected glands meal times. May be able to see whartons duct stone. Small stones may resolve spontaneously,but commonly need removal
295
What is 'tonsillitis'?
Inflammation of the palatine tonsil. Patients often present with sore throat and odynophagia/dysphagia if severe. Tonsils are typically enlarged and erythematous. Usually infective.
296
What might commonly cause viral tonsillitis?
Rhinovirus, adenovirus, accompanied by symptoms of URTI e.g. Dry cough
297
What might commonly cause bacterial tonsillitis?
Beta-haemolytic strep, accompanied by cervical lymphadenopathy, fever, pus
298
What is a peritonsillar abscess/quinsy?
Severe complication of bacterial tonsillitis. Patients typically systemically unwell with trismus or 'hot potato voice'. May appear to be drooling, due to dysphagia. Often unilateral uvula. Can deviate away from the lesion. Immediate (same day) referral to ENT!
299
What might cause a peritonsillar abscess/quinsy?
Strep pyogenes, staph aureus, h influenza, mixed flora
300
What sort of joint is the temporomandibular joint?
Modified hinge joint between the cranium and the mandible
301
Describe the articulation of the temporomandibular joint TMJ
The condyle of the mandible
Articulate tubercle of the temporal bone
Mandibular fossa
302
What divides the TMJ into superior and inferior compartments?
The articular disc
303
What stability has the TMJ joint capsule got?
Relatively loose, movement more important than stability
304
What 3 ligaments support the TMJ?
Lateral ligament (temporomandibular ligament)
Stylomandibular ligament
Sphenomandibular ligament
305
What muscles enable elevation of the TMJ?
Temporal, masseter, medial pterygoid
306
What muscles enable depression of the TMJ?
Lateral pterygoid, supra/infrahyoid (but mostly done by gravity)
307
What muscles enable protrusion of the TMJ?
Lateral pterygoid mainly
308
What muscles enable retrusion of the TMJ?
Temporal
309
What muscles enable lateral movements of the TMJ?
Temporal on same side, pterygoids of opposite side and masseter
310
What are the muscles of mastication, and what supplies them?
Temporalis, masseter and pterygoid are muscles of mastication and supplied by the mandibular branch of trigeminal nerve V3
311
What commonly causes a TMJ dislocation?
Commonly a sideways blow to the chin when the mouth is open, causing an anterior dislocation of the same side.
312
Describe a dislocation of the TMJ
Anterior dislocation. Head of mandible anterior to articular tubercle. Need to check for fracture on opposite side of jaw
313
What must you check for after a TMJ dislocation?
Need to check for fracture on opposite side of jaw
314
What might cause pain around the TMJ joint?
Bruxism (teeth grinding)
Osteoarthritis of TMJ
Inter-articular dist derangement
Commonly multifactoral causes e.g. Anatomical, psychological, social
315
What supplies the TMJ
Branches of V3 (auriculotemporal nerve)
316
What is the infratemporal fossa?
An irregularly shaped space deep and inferior to the zygomatic arch and deep to the famous of the mandible
317
Describe the borders of the infratemporal fossa
Anterior - posterior maxilla
Superior - inferior greater wing of sphenoid
Medial - lateral pterygoid plate of sphenoid
Posterior - temporal bone
Inferior - medial pterygoid muscle attachment at mandible
Lateral - ramus of mandible
318
List the contents of the infratemporal fossa
3 muscles - temporal muscle (inferior part), lateral pterygoid and medial pterygoid muscles
1 artery - maxillary artery
1 venous plexus - pterygoid venous plexus (communication with cavernous sinus)
Lots of nerves a mandibular, inferior alveolar, lingual, buccal, chorda tympani, and the otic ganglion
319
What does the mandibular branch of the trigeminal nerve give off?
Inferior alveolar nerve - innervation of lower teeth. This continues as the mental nerve
Lingual - sensory to the anterior 2/3 of tongue, and carries chorda tympani fibres from facial nerve for special sensory supply of same area
Buccal- sensory to cheek and buccal gum
320
What does the otic ganglion innervate?
Parasympathetic supply of parotid gland
321
Why is the infratemporal fossa clinically relevant?
Fossa can be a site for isolated infections e.g. In diabetic patients and tumours rarely.
If there is an infection present, there is a risk of cavernous sinus thrombosis due to the venous communication with pterygoid venous plexus
Fossa can be used for mandibular nerve blocks
322
What is the risk of an infection in the infratemporal fossa?
If there is an infection present, there is a risk of cavernous sinus thrombosis due to the venous communication with pterygoid venous plexus
323
What does the carotid sheath contain?
Common carotid artery, internal jugular vein and vagus nerve (CNX)
324
What are the 3 layers of deep cervical fascia in the head and neck? (From superficial to deep)
Investing layer, pretracheal layer, prevertebral layer
325
What forms the carotid sheath?
All 3 layers of deep cervical fascia
326
Where does the investing layer (most superficial of the deep cervical fascia layers) attach?
Surrounds neck like a collar. Superior margin attached to each side of the lower border of mandible (midline to angle), mastoid process, superior Michal line and external occipital protuberance. Also to spinous processes of vertebrae and ligamentum nuchae posteriorly. Inferiorly, upper border of manubrium, upper surface of clavicle, acromium and spine of scapula
327
Where is the middle deep cervical fascia layer, the pretracheal layer, found?
Thin, and limited to anterior parts of neck. Attached to hyoid bone superiorly, inferiorly extends to thorax where blends with fibrous pericardium
328
Where does the middle deep cervical fascia layer, the pretracheal layer, attach?
Attached to hyoid bone superiorly, inferiorly extends to thorax where blends with fibrous pericardium
329
Where does the carotid sheath extend?
Front the base of cranium through the root of the neck to the arch of the aorta
330
What does the innermost layer of deep cervical fascia, the prevertebral layer, do?
Forms a sheath for the vertebral column and surrounding muscles
331
Where does the innermost layer of deep cervical fascia, the prevertebral layer, extend?
Front he base of the cranium to the 3rd thoracic vertebra, and extends laterally as the axillary sheath that surrounds the axillary vessels and the brachial plexus of nerves.
332
What is the clinical significance of the planes of fascia?
Determine direction and extent infection might spread, as well as allowing easy separation during surgery.
333
Where is the retropharyngeal space?
Lies between the prevertebral layer of fascia and the fascia surrounding the pharynx (buccopharyngeal fascia, part of pretracheal fascia). Up until the age of 3-4yrs this space contains lymph nodes. Space is useful for talking/swallowing, but can be a space for infection collect.
334
How might a retropharyngeal abscess present?
Visible bulge on inspection of oropharynx, sore throat, difficulty swallowing, stridor, neck stiffness.
Important to recognise and treat early.
335
What are the buccinators?
The muscles of the cheek
336
What is the most common non traumatic cause of facial paralysis?
Inflammation of the facial nerve near its exit from the cranium at the stylomastoid foramen (Bells palsy). As facial nerve and it's branches run through the parotid gland and lie relatively superficial, vulnerable to damage in injuries/disease of the face
337
Most arteries supplying the face are branches of which vessel?
External carotid artery, which terminates as the superficial temporal artery and the maxillary artery. Before this it gives rise to facial artery
338
Where does the facial vein run?
Runs with the facial artery from the medial angle of the eye to the inferior border of the mandible. Drains into the internal jugular vein. Both internal and external jugular veins drain into the subclavian vein.
339
Why can the pulse of the facial artery be felt?
Artery winds around the inferior border of the mandible
340
Where do blood vessels supplying the scalp arise from?
Both the internal and external carotid arteries
341
Where do the most common cervical spine injuries occur?
C1/2 and C6/7
342
Where do the most severe cervical spine injuries occur?
Upper part of the spine, C1-4. Damage can lead to quadriplegia and cessation of respiratory movements.
343
What part of the spine is usually effected in hyperflexion injuries?
Lower part of cervical spine
344
Which part of the spine is usually affected by hyperextension injuries?
Upper cervical spine
345
What might cause a burst fracture of the C1 vertebrae?
Axial load injury (e.g. Falling onto head)
346
What is the cranial cavity?
The space within the cranium which holds the brain
347
What does the neurocranium consist of?
The calvaria (skull of cranial cap or roof of the cranium), and cranial floor.
348
What does the calvaria (skull or cranial cap or roof of cranium) consist of?
Two layers of compact bone, separated by a layer of spongy bone, known as diploe. Tri-lamina arrangement conveys protective strength without adding significant weight.
349
What is the pterion?
Lies on the lateral aspect of the skull, is the thinnest part of the calvaria. Fracture here risks injuring the middle meningeal artery (anterior branch), which lies immediately beneath the bone. This would cause extramural haematoma, with blood accumulating between the periosteal layer of the dura mater and bone, exerting pressure on underlying brain.
350
What is the risk of a pterion fracture?
Fracture here risks injuring the middle meningeal artery (anterior branch), which lies immediately beneath the bone. This would cause extramural haematoma, with blood accumulating between the periosteal layer of the dura mater and bone, exerting pressure on underlying brain.
351
What are the immobile joints of the skull known as?
Sutures (coronal, sagittal, lambdoid)
352
How may the cranial floor be divided?
Into 3 areas, or Fossae
- Anterior
- Middle
- Posterior
353
What might cause a basilar skull fracture?
Significant force transmitted thought the vertebral column
354
What might the signs of a basilar skull fracture be?
Battles sign (bruising over the mastoid process)
Raccoon eyes (bruising around both eyes)
Haemotympanum (blood behind the ear drum)
Bleeding and/or cerebrospinal fluid leakage from the ear (CSF otorrhea) and nose (CSF rhinorrhea)
355
What are the pharyngeal arches?
A sequence of ridges that form in the lateral wall of the embryonic pharynx, towards the cranial end of the neural tube. These arches will become apparent form approx 4 weeks in the developing embryo and form the structures of the future head and neck
356
What are the pharyngeal arches constituted of?
A large mesenchymal core (with some neural crest cells that migrate in), covered by ectoderm on its external surface
357
What is between the pharyngeal arches?
On the external surface is a pharyngeal groove of pharyngeal cleft. Clefts eventually disappear except the first, between the first and second arches, which becomes the external auditory meatus of the ear
358
What becomes of the pharyngeal grooves of pharyngeal clefts on the external surface of the pharyngeal arches?
Clefts eventually disappear except the first, between the first and second arches, which becomes the external auditory meatus of the ear
359
What does the ear arise from embryologically?
Arise from swellings, which form around the entrance to the meatus (from the cleft between the first and second arches, which becomes the external auditory meatus of the ear)
360
What covered the internal surface of each pharyngeal arch?
Endoderm (the part facing into the primitive gut tube)
361
What are pharyngeal pouches?
Pattern of grooves similar to pharyngeal clefts, but on the inside
362
What arises from the pharyngeal pouches?
Glandular structures e.g. Parathyroid, thymus and tonsils
363
What is the pharyngeal arches, their grooves (clefts) and pouches known as?
The pharyngeal apparatus
364
How many pharyngeal arches are there? What are the called?
5
1,2,3,4, and 6
Arch 5 does not exist in humans!
365
Describe the size of the pharyngeal arches
First is the largest, the rest get progressively smaller
366
What is associated with each pharyngeal arch?
Cartilage, nerve and artery
367
How are pharyngeal arches associated with cartilage?
Cartilage arises as a cartilage bar in each pharngeal arch, which will subsequently become a skeletal element of the head and neck. Cartilaginous bar of the 1st pharyngeal arch is the largest, known as meckels cartilage
368
Cartilaginous bar of the 1st pharyngeal arch is the largest, known as meckels cartilage, what does it give rise to?
Mandible, malleus and incus bones.
369
What do the 4th and 6th pharyngeal arches give rise to, with regards to cartilage?
Thyroid, arytenoids and cricoids
370
What cranial nerves are associated with the pharyngeal arches?
V, VII, and X
Arise from the lowest part of the brain stem and innervate the pharyngeal arches. Thus structural derivatives of each pharyngeal arch will be innervate do by the particular cranial nerve associated with that arch.
371
Are pharyngeal arches associated with blood vessels? If so, how?
Each pharyngeal arch becomes associated with an aortic arch blood vessel (the vessel that runs through the mesenchyme of each pharyngeal arch)
372
What does the facial skeleton arise from?
Arises from the frontonasal prominence and the first pharyngeal arch.
373
Where do the muscles of mastication arise from?
The first pharyngeal arch (thus are innervate but he trigeminal nerve CN V)
374
Where are the muscles of facial expression derived from?
The second pharyngeal arch (thus are innervate by the facial nerve CN VII)
375
What does the 6th pharyngeal arch give rise to, with regards to muscles?
The intrinsic muscles of the larynx
376
What are the vertebral arteries branches of?
Subclavian arteries
377
What do the vertebral arteries supply?
Posterior neck and posterior parts of the brain
378
Describe the route of the vertebral arteries through the head and neck
From its origin, ascends through the transverse foramina of the cervical vertebrae (except C7) and enters the subarachnoid space between the atlas and occipital bone. It then passes up through the foramen magnum, curving around the medulla, to join the other vertebral artery to form the basilar artery.
379
Describe the route of the basilar artery
Basilar artery runs along the anterior aspect of the brainstem.
380
Describe the origin of the right common carotid artery
Originates from the brachiocephalic artery behind the right sternoclavicular joint
381
Describe the origin of the left common carotid artery
Arises directly from the arch of aorta (thus is about 2cm longer than right common carotid artery)
382
How does the carotid artery ascend the neck?
In the carotid sheath
383
What is the carotid sheath derived from?
Fusion of the prevertebral layer of cervical fascia (posteriorly), the pretracheal layer (anteromedially) and the investing layer of cervical fascia (anterolaterally).
384
Describe the arrangements of the components of the carotid sheath
Artery lies medially within the sheath, vein is lateral, and the nerve behind and in between the vessels. Sympathetic trunk
lies OUTSIDE the sheath, medially and behind it
385
Where do the common carotids terminate?
Level with the upper border of the thyroid cartilage, by dividing into internal and external carotid arteries. At division internal artery is more bulbous due to carotid sinus.
386
Where is the carotid sinus found?
At division of common carotid arteries (level with upper border of thyroid cartilage) internal artery is more bulbous due to carotid sinus.
387
How many branches has the external carotid artery got?
8. It is a major source of blood supply to extra-cranial structures of the head and neck region.
388
Where do the veins draining the head and neck lie?
Either superficial or deep into the investing layer of deep cervical fascia in the neck
389
Are there any distinct fascia layers in the face?
No. Muscles attach between bone and skin.
390
List an important anastamosis of the facial vein
Facial vein receives blood from the superior and inferior ophthalmic veins, which have a direct connection with the pterygoid venous plexus and with the cavernous sinus.
391
What is the cavernous sinus? What are its implications?
Lies inter-cranially and is a part of the intercranial venous system. Implications for infections as they have a route to track into intercranial structures. Septic thrombi formed in facial vein can lead to cavernous sinus thrombosis.
392
What are the emissary veins of the skull?
Run through the skull, between the intro cranial and extra cranial blood vessels. Intracranial (dural) venous sinuses. No valves, so potential route of infection from scalp to cranial cavity.
393
What might enlarged lymph nodes be a sign of?
Disease in the area it drains
394
What are the major groups lymph nodes can be arranged into?
Regional (or superfical)
| Terminal (or deep)
395
Where are terminal lymph nodes found in the head and neck?
Lie within the neck, deep to the investing layer of cervical fascia. Called collectively the 'deep cervical nodes'
396
What does the jugulo-digastric lymph node drain?
Also called the tonsillar node. Lymph drainage of pharyngeal tonsil and tongue
397
Where is the jugular-digastric lymph node found?
Located just below and behind the angle of the mandible
398
What does the jugulo-omohyoid lymph node drain?
Lymph drainage of the tongue, oral cavity, trachea, oesophagus, and thyroid gland.
399
When might the supraclavicular lymph nodes be enlarged?
Malignancies of the abdomen and thorax
400
What is the bifurcation of the trachea level with?
The sternal angle on the arch of aorta
401
What blood vessel does the right recurrent laryngeal nerve loop under?
Right subclavian artery
402
What blood vessel does the left recurrent laryngeal nerve loop under?
Arch of aorta
403
Describe the route of the 3 branches of the trigeminal nerve
V1 Opthalmic - superior orbital fissure, into orbit
V2 Maxillary - foramen rotundum, into pterygopalatine fossa
V3 Mandibular - foramen ovale, into infratemporal fossa
404
Which cranial nerves pass into the orbit?
2, 3, 4, 5 (ophthalmic division), 6
405
In which fossa does the pituitary gland sit?
Within the hypophyseal fossa (the deepest part of the sella turcica), within middle cranial fossa.
406
What occurs in the optic chiasm?
Area where a portion of the optic nerves from either retina cross over to their contralateral side before continuing posteriorly as the optic tracts
407
Do sympathetic or parasympathetic neurones have longer preganglionic nerves?
Parasympathetic
408
Do sympathetic or parasympathetic neurones have longer postganglionic nerves?
Sympathetic
409
How many ganglia are associated with the head and neck ANS
4
410
What are the 4 ganglia associated with the head and neck called?
Ciliary
Pterygopalatine
Submandibular
Otic
411
What does it mean if a pupil is 'fixed'?
It won't constrict to light being shown in the pupil
412
Where does conductive hearing loss arise from?
Pathology affecting the external or middle ear
413
Where does sensorineural hearing loss arise from?
Secondary to pathology affecting the inner ear or CN VIII (8)., from her to where it enters the brainstem (including its nuclei in the brainstem)
414
What is the function of the larynx?
Respiration (open valve), phonation (partially closed valve), protecting trachea/bronchial tree (swallowing), cough reflex
415
Where is the supraglottis?
Inferior surface of epiglottis, vestibular folds (false cords)
416
Where is the glottis?
The vocal cords (including 1cm inferiorly)
417
Where is the subglottis?
Down to lower border of cricoid cartilage
418
What is the function of the larynx?
Respiration (open valve), phonation (partially closed valve), protecting trachea/bronchial tree (swallowing), cough reflex
419
Where is the supraglottis?
Inferior surface of epiglottis, vestibular folds (false cords)
420
Where is the glottis?
The vocal cords (including 1cm inferiorly)
421
Where is the subglottis?
Down to lower border of cricoid cartilage
422
What are the main structures of the larynx?
Epiglottis, thyroid cartilage, cricoid cartilage, arytenoid cartilage, (paired) vocal cords
423
What is the epiglottis?
Leaf shaped plate of elastic fibrocartilage, attached posterior to thyroid cartilage by thyroepiglottic ligament.
424
What is the Vallecula?
A depression between the tongue base and epiglottis
425
Describe the presentation of the thyroid cartilage
Laryngeal prominence 'Adams apple'. Largest cartilage comprising 2 lamina. Superior and inferior thyroid horns (hyoid and cricoid respectively)
426
Describe the presentation of the cricoid cartilage
Most inferior cartilage, completely encircles the airway. Signet ring shape. 2 articular facets on each side. Superiolateral surface for arytenoid cartilage. Lateral surface for the medial surface of inferior horn of thyroid cartilage.
427
Describe the presentation of the arytenoid cartilage
Pyramid shape. Concave base articulating with cricoid. Involved with vocal cord movement.
428
At what cervical level is the hard palate?
C1
429
At what cervical level is the angle of mandible?
C2
430
At what cervical level is the hyoid bone?
C3
431
At what cervical level is the thyroid cartilage?
C4/5
| Upper and lower
432
At what cervical level is the cricoid cartilage?
C6
433
What are the layers of the vocal cord?
Stratified squamous epithelium
Reinkes space
Vocal ligament
Vocalis muscle
434
What muscle abducts the vocal cords?
Posterior cricoarytenoid
435
What muscle adducts the vocal cords?
Lateral cricoarytenoid
436
Describe the arterial blood supply to the larynx
Superior laryngeal artery (superior thyroid artery)
| Inferior laryngeal artery (inferior thyroid artery)
437
Describe the venous drainage of the larynx
Superior laryngeal vein
| Inferior laryngeal vein
438
Describe the laryngeal nerve supply
Superior laryngeal nerve - deep to carotid arteries
Internal - pierces through thyrohyoid membrane
External - deep to superior thyroid artery, supplying cricothyroid muscle
439
Where does the right recurrent laryngeal nerve curve under?
Subclavian artery
440
What does the left recurrent laryngeal nerve curve under?
Under aortic arch
441
What does the pharynx consist of?
Nasopharynx, oropharynx, laryngopharynx, adenoids, tonsils, constrictor muscles, blood/nerve supply
442
What does the larynx consist of?
Supraglottis, glottis, subglottis, epiglottis, thyroid, cricoid, arytenoid cartilages, vocal cords, blood/nerve supply
443
What sort of cancer is hypopharyngeal/laryngeal carcinoma usually?
SCC
444
What vertebral level is the nasopharynx?
C1, C2
445
What are the boundaries of the nasopharynx?
Base of the skull to the upper border of the soft palate
446
What are the contents of the nasopharynx?
Pharyngeal tonsil, openings of the Eustachian tube, adenoids
447
What pathology may the adenoids cause?
Block nasal air flow (mouth breathing, snoring)
Potentially block Eustachian tube opening
Harbour chronic infection (which can transmit to Eustachian tube of sinuses, otitis media, sinusitis)
448
Describe the classic theory of formation of otitis media
Cells in the middle ear are constantly reabsorbing N2/O2. Blocked ET creates negative pressure in middle ear. Transudate drawn from mucosa. Bacteria now proliferate to cause otitis media.
449
What are some possible complications of otitis media?
Hearing loss (usually temporary, associated with effusion)
Inflammation of mastoid (necrosis of mastoid process)
Cholesteatoma (cyst like lesions that are linked to chronic infection. Can erode surrounding structures)
Meningitis, brain abscess
450
What are the boundaries of the oropharynx?
Soft palate to epiglottis
451
What vertebral level is the oropharynx?
C2, C3
452
What are the contents of the oropharynx?
Palatine tonsil
453
What are the boundaries of the laryngopharynx?
Epiglottis to top of cricoid cartilage
454
What is the vertebral level of the laryngopharynx?
C4, C5, C6
455
What are the contents of the laryngopharynx?
Piriform fossa
456
What are the 3 longitudinal muscles that elevate the pharynx and larynx during swallowing?
Stylopharyngeus
Palatopharyngeus
Salpingopharyngeus
457
What nerve innovates stylopharyngeus?
Glossopharyngeal CN IX
458
Where does stylopharyngeus lie?
From posterior border of thyroid cartilage to styloid process
459
Where is palatopharyngeus?
Hard palate to posterior border of thyroid cartilage
460
Which nerve innervates palatopharyngeus?
Pharyngeal branch of vagus CN X
461
Where is salpingopharyngeus?
Cartilaginous part of ET - merges with palatopharyngeus.
462
Which nerve innervates salpingopharyngeus?
Pharyngeal branch of vagus CN X
463
List the 3 circular pharyngeal constrictor muscles (construct walls of pharynx when swallowing)
Superior pharyngeal constrictor
Middle pharyngeal constrictor
Inferior pharyngeal constrictor
464
What are the 2 parts to the inferior pharyngeal constrictor?
Thyropharyngeal and cricopharyngeal
465
What is the significance to the inferior pharyngeal constrictor muscle having 2 parts?
Potential point of weakness between the 2 parts, killians dehiscence
466
What might cause a pharyngeal pouch?
Failure of UOS to relax, or abnormal timing of swallowing (essentially a higher pressure in the laryngopharynx).
467
What is a pharyngeal pouch?
A postermedial (false) diverticulum. Symptoms relate to food material collecting in pouch or disruption of swallowing
468
What is the one muscle of the pharynx NOT innervates by CN X?
Stylopharyngeus- glossopharyngeal nerve CN IX
469
Which nerve does sensory innervation of the nasopharynx?
Maxillary nerve CN V2
470
Which nerve does sensory innervation of the oropharynx?
Glossopharyngeal nerve CN IX
471
Which nerve does sensory innervation of the laryngopharynx?
Vagus nerve CN X
472
Describe the first (oral) stage of swallowing
Voluntary. Preparatory phase (making bolus). Transit phase (bolts compressed against palate and pushed into oropharynx by tongue and soft palate). Hypoglossal nerve CN XII, muscles of the tongue
473
Describe the second phase of swallowing (pharyngeal phase)
Involuntary. Tongue positioned against hard palate (food cannot renter mouth) CN XII.
Soft palate elevated, sealing off nasopharynx (tensor palatine CN V3, levator palatine CN X). Opens ET tube.
Suprahyoid (CN V3, CN VII, CN XII) and longitudinal muscles shorten (CN IX, CN X). Pharynx widens and shortens to receive bolus. Larynx elevated and sealed off by vocal cords/folds.
Epiglottis close over larynx (result of elevated hyoid)
Bolus moves through pharynx by sequential contraction of constrictors. Relaxation of UOS
474
Describe the 3rd stage of swallowing (oesophageal)
Involuntary. Upper striated muscle of oesophagus CNX. Lower smooth muscle. LOS as covered in GI unit
475
List some potential causes of dysphagia
Stroke, progressive neurological disease, COPD, dementia
476
List some signs/symptoms of dysphagia
Coughing/choking, drooling (sialorrhoea), recurrent pneumonia, changes in voice/speech (wet voice), nasal regurgitation
