Head And Neck

Question 1

Identify the major muscle groups of the head and neck, and recall their nerve innervation. Notion

Answer 1

Face - facial nerve
Occipitofrontalis - temporal branch
Obicularis oculi - One circling around each bony orbit. Flat, constrictor muscle. Orbital (zygomatic) and Palpebral (temporal).
Obicularis oris - surrounding orifice of mouth. Flat, constrictor muscle & forms majority of lips.
Arises from maxilla & mandible and inserts into skin and membrane of lips - buccal and mandibular.
Buccinator - wall of cheek
Zygomaticus major - comes from zygomatic bone. Buccal and zygomatic.
Risorius - buccal
Platysma - Arises from fascia overlying anterior chest. Inserts into lower part of the mandible, subcutaneous tissue on skin of lower face. - cervical branch of facial nerve.

Neck:
Supra- and infra-hyoid muscles
Scalene - form the floor of the posterior triangle.
sternocleidomastoid - accessory nerve
trapezius - Origin: occipital bone, nuchal ligament
Inserts: lateral 1/3 clavicle & acromion of scalula. Accessory nerve.

Muscles of Mastication (act on the mandible at the temporomandibular joint for chewing). Supplied by branches from the mandibular division of the trigeminal nerve (a branch of CN V).
1. Temporalis
2. Masseter
3. 2xMedial and 2xlateral pterygoids - Attach to two vertical bony ‘wings’=pterygoid plates on inferior of skull

Question 2

Describe and demonstrate the action of the major muscle groups of the head/face and
neck.

Answer 2

Occipitofrontalis raises eyebrows and wrinkles forehead.
Orbicularis oculi -: two key parts: orbital (squeezes eyelids) and palpebral ( gently closes) protects eye & keeps front of eye moist - sweeps tear film across the surface of the eye.
Orbicularis oris - Purses lips together- contributes to facial expressions and speech Seals mouth closed- keep food/fluid inside oral cavity.
Buccinator - Holds cheek in towards teeth e.g. when chewing food (prevents food from collecting between cheek and gum) Contract buccinator to expel air against pursed lips e.g. playing trumpet.
Risorius and zygomaticus major are dilators of mouth.
Platysma - Tenses skin of anterior neck (also acts to draw down and lower inferior lips).

Elevate mandible = temporalis (also retracts mandible), masseter(also protracts mandible) and medial petrygoid.
Depress = suprahyoids and lateral pterygoid.
The pterygoids act together to move mandible from side to side.

Sternocleidomastoid - Origin: clavicle and sternum Inserts: mastoid process Action: rotates head, so chin turns up to opposite side
Acting together- flex neck
Trapezius - elevates the shoulder; acts also to stabilise the scapula - rotate it when above 90 degrees.

Suprahyoid muscles (4) are above the hyoid bone- attach to jaw or base of skull to hyoid bone.
Elevate the hyoid + Depress the mandible.
Infra hyoids muscles overlie the larynx and thyroid gland.
Depress the hyoid and help stabilise it.

Question 3

Describe and identify the boundaries of the anterior, posterior and carotid triangles,
identify their surface anatomy and the key anatomical contents.

Answer 3

Anterior triangle - Superiorly – inferior border of the mandible,
Laterally – anterior border of the sternocleidomastoid, Medially – midsagittal line of the neck.
Surface = thyroid and cricoid cartilage and thyroid gland.
Roof = investing fascia

Carotid triangle -Boundaries: Superior -Pos. belly digastric
Medial -Superior belly omohyoid
Lateral - Sternocleidomastoid
Has CCA, IJV and vagus nerve.

Posterior- The anterior border is the posterior border of sternocleidomastoid muscle. The posterior border is the anterior margin of the trapezius muscle. inferior border is the middle one-third of the clavicle.
Floor is scalene
Roof is Superficial cervical fascia which has Accessory Nerve+External jugular vein
Posterior belly of omohyoid passes through triangle.
Also brachial plexus, subclavian vein and artery, phrenic nerve.

Question 4

Identify and describe the general anatomical organisation of neck structures when
viewed in cross-section (infra-hyoid view).

Question 5

Describe the arrangement of neck structures within the cervical facial layers

Answer 5

Superficial cervical fascical (adipose):
superficial blood vessels e.g. anterior and external jugular veins, cutaneous nerves, superficial lymph nodes and the platysma muscle.

Investing - like a collar. Superior is attached to lower border of mandible, mastoid process, superior nuchal line and external occipital protuberance. Posterior is spinous vertebrae and ligamentum nuchae. Inferior is upper border of the manubrium, the upper surface of the clavicle, acromion, and spine of the scapula. It splits to enclose the sternocleidomastoid and trapezius muscles, and the submandibular and parotid salivary glands.

Pretracheal - Superior attached to hyoid and inferior to pericardium. Splits into muscular layer which has infrahyoid muscles and visceral which has thyroid, trachea and oesophagus.
Then becomes buccopharyngeal fascia as it surrounds pharynx and oesophagus which ends at diaphragm. Starts at base of skull.

Carotid sheath - from skull to root of neck and to arch of aorta. Contains common carotid artery, internal jugular vein and the vagus nerve (CN X).

Prevertebral - sheath for the vertebral column and muscles associated with it. This layer extends from the base of the cranium to the 3rd thoracic vertebra. Also extends laterally as the axillary sheath that surrounds the axillary vessels and the brachial plexus.

Question 6

Explain the implications for the spread of deep neck space infections due to the
compartmentalisation and boundaries of the cervical fascial planes.

Answer 6

infection or an abscess can develop between the fascial planes.

retropharyngeal space - between prevertebral layer of fascia and the buccopharyngeal fascia. The space extends the length of the neck inferiorly, into the mediastinum.
Thus retropharyngeal space infections can spread inferiorly into the thorax, and cause mediastinal complications e.g. mediastinitis,
and retropharyngeal abscesses. Or also goitres.

RAb is usually secondary to an infection involving the upper respiratory tract that spreads to involve the retropharyngeal lymph nodes within the supra-hyoid region in children under 5. In adults due to penetrating injury that allows bacteria to enter.
can compress airways and structures, visible bulge on inspection of the oropharynx, sore throat, difficulty swallowing, stridor, reluctance to move the neck and a high temperature.

Retrosternal goitres go through root of the neck into the superior thorax, via the thoracic inlet. Compress trachea and venous blood vessels.
Signs = facial plethora, breathlessness or stridor.

Question 7

Identify the major arteries and veins of the head and neck, their general course and
related surface anatomy, particularly in relation to the common carotid artery, its
terminal branches (internal and external carotid) and the internal and external jugular
vein [introduced in this Session but picked up mainly in Session 2].

Answer 7

Bifurcation of CCA is at C4 vertebra - upper level of thyroid cartilage, can form plaque

Internal carotid artery
Proximal point indicates carotid sinus. Carotid body located in adventitia of blood vessel bifurcation
Ascends neck and giving no branches in neck
Runs through base of skull within petrous bone- carotid canal
Exits carotid canal before entering into cavernous (underneath base of skull)
sinus
Exits top of cavernous sinus and gives its branches
- ophthalmic artery- into orbit - branches that supply cerebral arterial circulation

External
Exits the carotid sheath
Supplies arterial anastomosis supplying scalp
Eight branches:
Superior thyroid artery
Ascending pharyngeal
Lingual
Facial
Occipital
Posterior auricular
Maxillary
Superficial temporal artery

Terminates as superficial temporal artery ( can be affected in a condition called temporal arteritis. In older people as a unilateral headache and jaw claudication) and maxillary.

Maxillary a. many branches:
middle meningeal art - enters intracranially to supply meninges sphenopalatine art—supplies nasal cavity; source for epistaxis

Question 8

Neck definition

Answer 8

extends from the lower margin of the mandible (jaw) to the suprasternal notch of the manubrium and the upper border of the clavicle below, connecting the head to the rest of the body.

Question 9

Facial nerve lesions

Answer 9

Complicated route from intracranial to extracranial, - From brainstem  bony channel in base of skull -
Exits base of skull  runs through parotid gland -
Gives branches to muscles of facial expression

Most common = Bell’s palsy

Sudden onset of ipsilateral facial muscle weakness or paralysis

House-Brackmann Scale used to indicate severity (Grades I- VI)

Paralysis is usually temporary Important to assess eye occlusion… Inability to fully close eye - eye protection required - referral to ophthalmologist

Question 10

Torticollis

Answer 10

Involuntary contraction of SCM Causes asymmetrical head/neck position Variety of causes- can be congenital and acquired

Question 11

Trigeminal nerve

Answer 11

3 divisions:
Ophthalmic (the skin, mucous membranes and sinuses of the upper face and scalp) is sensory. Branches - supraorbital, supratrochlear, nasociliary, lacrimal.
Maxillary (middle 3rd) is sensory. Branches are infraorbital, superior alveolar
Mandibular is both. Branches are inferior alveolar, auriculotemporal and mental nerve.

Question 12

Communication between extra- and intra-cranial veins:
potential route for spread of infection

Answer 12

Ophthalmic veins draining orbit - drain into facial vein but also - drain into intracranial venous structure- cavernous sinus
cv
Route for orbital infections to
spread intracranially

Facial vein
Runs from medial angle of the eye towards the inferior border of the mandible
Then joins IJV
connects with both the superior and inferior ophthalmic veins, which have a direct connection with the cavernous sinus and the pterygoid venous plexus.
The cavernous sinus lies intra-cranially - Route for infections of central face/nasal cavity to spread intracranially

Question 13

Describe and locate the clinically relevant pulses in the neck namely for palpation of the
(note: not all groups are at the same time) carotid artery and inspection of the jugular venous pulsation and explain the relevance of this knowledge to clinical practice (e.g. measuring JVP and central line access).
Lecture

Answer 13

Measuring Jugular Venous Pressure-
venous pulsation from right IJV patient at 45 degrees
Vertical height of pulsation visible in neck- gives indication of pressures within right atrium
Raised in certain diseases e.g. fluid overload, heart failure

Insertion of central line into internal jugular vein (usually right)
Central venous access e.g for drug infusions, continuous monitoring of central venous pressure
Under Ultrasound guidance!
Point of access between two heads of SCM
Using subclavian vein- higher risk for causing pneumothorax

Carotid Endartectomy
Incision into neck in region of carotid triangle
Common and internal carotid a. identified and incised
Removal of atherosclerotic plaque

Carotid pulse” more easily palpated Carotid sinus massage
- applies pressure to baroreceptors -increase parasympathetic outflow to heart -helps terminate certain types of tachyarrhytmias (SVT)

Question 14

Identify the major veins of the head and neck, their general course and
related surface anatomy - the internal and external jugular
vein

Answer 14

Internal Jugular Vein
Lies Lateral to Common (then Internal) Carotid Artery Throughout Neck
Begins at jugular foramen (base of skull) as continuation of sigmoid sinus
Descends length of neck in carotid sheath and for most of route, deep to SCM
Receives several veins en route e.g. facial vein, and veins draining thyroid gland and tongue
End as Joins with subclavian vein to continue as brachiocephalic vein- SVC Right atrium

External jugular vein formed by vein draining scalp and veins draining deep face
Runs in superficial cervical fascia
Superficial to SCM, then in roof of posterior triangle
Drains into subclavian vein

Question 15

Identify the major arteries of the head and neck, their general course and
related surface anatomy

Answer 15

Middle Meningeal Artery
Enters into skull via foramen spinosum
Runs just below thinnest/weakest part of skull- pterion Risk of rupture if this part of skull is fractured
Leading to extradural haemorrhage

Vertebral arteries
First branch of subclavian artery Supply posterior neck and posterior parts of the brain (e.g. brainstem, cerebellum).
Ascends up neck within transversa formina C6- C1
Pierces posterior atlanto-occipital membrane ( between occipital bone and C1) enters intracranial via foramen magnum
Right and left vertebral artery join within skull to form basilar artery

Question 16

Outline common and important pathology affecting the lymphatic system, which may give rise to lymphadenopathy in the neck (e.g. infection, malignancy).

Answer 16

Lymphadenopathy due to:
i) infection and/or inflammation in the tissues drained by that lymph node
ii) malignancy: either from metastases to the lymph node (from cancer involving
a distant tissue drained by that lymph node) or a primary malignancy involving
cells found within the lymph nodes e.g. lymphoma.

Question 17

Recall the tonsils forming Waldeyer’s ring of lymphoid tissue, their location and general role in defense against infection

Answer 17

Annular Collection of Lymphoid Tissue (NOT LYMPH BODES) Surrounding Upper Aerodigestive Tract

Enlargement Pharyngeal Tonsil =adenoids = Obstruction of nasal breathing, Blockage of eustachian tube -leading to middle ear problems)

Enlargement of Palatine Tonsils
= tonsillitis = usually viral or step pyogenes

Question 18

Describe and identify the general location of the superficial lymph nodes and the general areas of the head and neck that these drain.

Answer 18

occipital drains posterior scalp.
post auricular = posterolateral scalp
pre-auricular= anterolateral scalp, upper half of face
submental = chin, floor of mouth, tip of tongue, lower teeth and gums
submandibular nodes= centre of face
Teeth
Anterior tongue

Regional lymph nodes drain specific areas and, lie superficially within the superficial cervical fascia.
can be readily palpated.

Question 19

Describe and recognise the red flags for lymphadenopathy (causing a neck lump), which indicate concerning underlying pathology e.g. head and neck cancer, metastases involving lymph nodes.

Answer 19

Fixed, hard and irregular (palpation findings)
Rapidly growing in size (and size >2cm)
Associated with generalised lymphadenopathy
Systemic signs/symptoms such as weight loss, night sweats or other features suggestive of haematological malignancy Associated with a persistent (unexplained) change in voice/hoarseness or difficulty swallowing or other features of a head and neck cancer

Question 20

Describe common/important causes of neck lumps (including but not limited to lymphadenopathy) and the key symptoms and clinical examination findings associated with them

Answer 20

Benign lesions of skin or subcutaneous tissue e.g. sebaceous cyst

Lymphadenopathy due to underlying systemic disease e.g. HIV

Congenital lesions (children) e.g. dermoid cyst, cystic hygromas - collection of fluid -filled sacs, compressible and transilluminable, found midline below level of hyoid bone beneath deep cervical fascia. Non-tender, well-defined. Can become secondarily infected. classically in posterior triangle: affects infants <2 years. Moves up and down with swallowing & tongue protrusion.

Thyroid gland pathology - Malignant or benign neoplasms, Diseases that diffuse lay enlarge e.g. Grave’s disease

Salivary gland pathology - Calculus, infection,

Vascular e.g. carotid body tumour: carotid artery aneurysm (rare), suspect if pulsatile mass in neck; can move side-to-side, but not up and down

Question 21

Deep cervical lymph nodes

Answer 21

Terminal lymph nodes lie deep to the investing layer of deep cervical fascia. receive all the lymph including lymph drained first via the regional.
Deep structures will drain directly to deep nodes.
closely related to the internal jugular vein, within the carotid sheath.

The jugulo- digastric node (also called the tonsillar node) is located just below and behind the angle of the mandible. lymph drainage of the palatine tonsil, oral cavity and the tongue. swollen and tender in tonsillitis

The jugulo-omohyoid node is mainly associated with the lymph drainage of the tongue, oral cavity, trachea, oesophagus and the thyroid gland.

supraclavicular nodes found in the posterior triangle, at the root of the neck on either side. Left = abdominal cavity and thorax - irchow’s node - gastric cancer
Right = mid section chest, Oesophagus, lungs
they receive lymph from these areas before it drains via the thoracic duct into the venous circulation.

Question 22

Describe the arrangement of the meningeal layers in relation to the brain and skull, the contents of the subarachnoid space and some of the key blood vessels found in relation to these layers (i.e. middle meningeal artery and
bridging veins).

Answer 22

Inner to outer (first 2 = leptomeninges):
Pia - stuck to brain tissue

Arachnoid - subarachnoid is CSF, cerebral arteries, cerebral veins.
Does not go into sulci and lateral fissure but does go into longitudinal fissure.
Soft, fibrous, translucent.

Dura - tough fibrous.
Has potential subdural space.
Meningeal arteries on outermost surface.

Question 23

Name and identify the reflections of the dura mater (dural folds) and describe the
formation of the dural venous sinuses

Answer 23

Dura fuses with the periosteum lining inner table of skull bones
Has two layers in skull
– Periosteal – part against the inner table of bone
– Meningeal = part adjacent to arachnoid

• Separation of two layers forms
– Dural folds

1. Falx cerebri - in longitudinal fissure that separates the hemispheres.
   Attachment to anterior cranial fossa at Crista gala.
   Posteriorly on top of tentorium cerebelli.
2. The opening within the tentorium cerebelli allows passage of the brainstem and is called the tentorial notch.

– Dural venous sinuses (spaces which are filled with venous blood). This is where cerebral veins drain into. And sinus drains into IJV.

Help to Stabilise the Brain and act as Rigid Dividers.
BUT
A rise in pressure inside the skull can lead to compression and displacement (herniation) of parts of brain against rigid dural folds (1-3) and/or through foramen magnum (4)

Question 24

Name and identify the dural venous sinuses and describe their drainage into the internal
jugular vein, their connection to cerebral veins (via bridging veins) and extracranial veins
The significance of this for the spread of infection.

Answer 24

All connected to each other.
Cerebral veins connect via bridging veins - subdural haemorrhage
Scalp veins connect via emissary veins - scalp infection can spread to intracranial structures.

3. Superior Sagittal sinus - underneath sagittal suture
4. Inferior Sagittal sinus - inferior margin of falx cerebri
5. Straight venous sinus - underneath occipital bone at the confluence of sinuses. Connects superior to inferior sinus. At the base of falx cerebri where it’s on top of tentorium cerebelli.
6. Transverse sinuses. Extend laterally from confluence. Go towards jugular foramen.
7. Sigmoid sinus - s shaped bend of transverse sinus when it is going towards jugular foramen.
8. Cavernous sinus - middle cranial fossa either side of body of semoid?
9. Superior and inferior petrosus sinus - superior connects cavernous to transverse and inferior connects it to sigmoid.

Question 25

Describe the likely origin of bleeding in extradural and subdural haemorrhages and with reference to the meningeal anatomy explain the radiographic appearance of extra- and sub-dural haemorrhages.

Answer 25

Intracranial haemorrhage - addition of ‘volume’ to an already fixed space, due to skull, leads to rise in pressure and damage to brain tissue, brainstem, cranial nerves etc.

It can be:

– Extradural - middle meningeal artery between periosteal layer of dura and inner table of bone.
Runs beneath thinnest part - near pterion - can be fractured
When it bleeds it strips periosteal layer away from bone. Convex - lateral expansion stopped by edges of bone.
Headache, Lucid interval and 1 hour later fast deterioration.

– Subdural - point of weakness is when bridging vein joins wall of venous sinus.
Can fill one hemisphere - Stopped by longitudinal fissure.
Crescent
Minor or major trauma with headache
Cortical shrinkage in elderly patients puts them at risk
Gradual deterioration

– Subarachnoid - circle of Willis
Trauma or aneurysm
Sudden sig headache
Blood leaks into space and mixes with CSF
Need CT scan. If inconclusive- lumbar puncture.

• Bleeding can also occur within the brain tissue itself (e.g. contusions, tearing of white matter) – Intracerebral haemorrhage

Question 26

Describe and identify the origin and entry of the cranial nerves in relation to the
brainstem.

Question 27

• Describe the clinically relevant aspects of the intracranial and extracranial routes of the cranial nerves and their relationship to other anatomical structures in the head and neck. •

Answer 27

CN 1
olfactory receptors
(within epithelium in superior part of nasal cavity either side of nasal septum)
Travels up through base of skull cribriform foramina
Olfactory bulb
Olfactory tract
Temporal lobe

CN 2
Retinal ganglion cells
Optic nerve
Exits back of orbit via optic canal
Fibres from left + right merge optic chiasm
Right and left optic tracts
Some communicate into brainstem (light intensity so controls pupil size)
Subarachnoid space extends into optic nerve

CN 3
Close relationship to tentorium cerebelli edge - runs via cavernous sinus - enters orbital cavity

CN 4
Dorsal midbrain - via cavernous sinus - enters orbital cavity - superior oblique muscle

CN 6
From caudal pons - via cavernous sinus - enters orbital cavity

CN 5
Pons→target tissues
Face, scalp, eye, deep facial structures
Anterior 2/3rd tongue (general sensation only NOT taste)- Vc
Muscles of mastication- Vc

Question 28

Use anatomical understanding to explain the involvement of certain cranial nerves, and subsequent clinical signs in patients presenting with injury or pathology involving structures of the brain, head/face or neck.

Answer 28

CN 3 - motor + para
Somatic efferent fibres supply all extra ocular muscles and levator palpebrae superioris
Visceral efferent fibres - para - muscles inside eye ball

Signs due to somatic +/- para
Report double vision (dipoplia)
Ptosis
Abnormal position of eye - down and out

Conditions
Microvascular ischaemia
Risk factors: age (>50 years),
diabetes/hypertension

Compressive (lesion compresses onto ‘outside’ of CN III) - pupil involving
Aneurysmal (PCA) - associated with headache/retroorbital pain
Head injury
Tentorial (uncul) herniation e.g. secondary to inc ICP
Para nerves on outside so can cause blown pupil

CN 4
Acquired - microvascular ischaemia
Trauma (even minor)
Intracranial tumour (could compress/stretch CN IV)

CN 6
Diplopia worse in lateral gaze on size of lesion
Abnormal eye position at restUnable to move it laterally

Microvascular ischaemia
Head injury, tumour
Raised ICP can cause downward displacement of brain and stretch →false localising sign

CN 5
Trigeminal herpes zoster (VZ in trigeminal ganglion)
Trigeminal neuralgia (compression from an aberrant blood vessel)
Orbital and mandibular fractures (distal branches of CN V divisions)
Posterior cranial fossa tumours

Question 29

• Describe the key functions of the 12 cranial nerves and how clinically these are tested.

Answer 29

Trigeminal
1. Sensory to skin and tissues of face, portion of scalp, surface of eye & deep facial structures
2. Anterior 2/3rd tongue (general sensation only NOT taste)
3. Muscles of mastication (via branches of Vc)

Clinical test
Sensory deficits within the dermatomal regions (on affected side)
Weakness in muscles of mastication
Absent corneal reflex - CN Va is ophthalmic division and is sensory part of this reflex.

Question 30

Describe and identify the external features of the cerebrum (gyri, sulci and lobes), diencephalon, brainstem and cerebellum, and their principle functions.

Answer 30

Forebrain is the cerebrum and diencephalon

Brainstem is Midbrain, Pons,
Medulla
Cranial nerve nuclei located within brainstem
Sensory and motor pathways run up & down through brainstem
Midbrain involved in pathways for eye movement co-ordination and pupillary response to light
Pons involved in pathways for Feeding, Sleep and consciousness
Medulla involved in pathways for Cardiovasc & respiratory function

Cerebellum

External appearance of forebrain:
Grey matter:
Cortex
Sulci & gyri
Fissures:
Longitudinal, Lateral
White matter

Question 31

Recall the major functions of the lobes
identify the specific cortical areas involved in:
voluntary motor control
sensory perception

the topographic representation of the face and body [homunculus])

Answer 31

Frontal - Voluntary motor control
(Pre-central gyrus = primary motor cortex)
Speech production
- Social behaviour
Impulse control
- Higher cognition (planning, thinking)

Parietal control
- Somatosensory perception (Post-central gyrus = primary
somatosensory cortex)
Spatial awareness

Occipital - Visual perception

Temporal - Language - Emotion - Long-term memory - Sense of Smell - Hearing - Taste

Cerebellum - Co-ordination and motor learning

Question 32

• Identify the topographical anatomy of the brain, brainstem and cerebellum as seen on
cross-sectional imaging i.e. CT and MRI (in transverse and mid-saggital planes).

Question 33

Describe embryological development of the head and neck
with relationship to pharyngeal
arches, clefts and pouches.

Answer 33

Pharyngeal Arches
What - sequence of ridges that form in the lateral walls of the embryonic pharynx, towards the cranial end of the neural tube. Apparent from 4 weeks.

Structure - mesenchyme core covered by ectoderm on its external surface. Internal arches covered by endoderm.
Between each arch on external surface is cleft. Between each arch internally is pouches.
Each arch has associated cartilage, nerve, artery.
cartilage arises as a cartilage bar in each pharyngeal arch, which will subsequently become skeletal element.

How many - 6 but 5th does not form.

1st arch - largest, Meckels cartilage that gives rise to mandible, malleus and incus bones. maxillary and mandibular prominences.
Trigeminal nerve
Muscles of mastication
First cleft is external auditory meatus and first pouch is Eustachian tube and they are separated by tympanic membrane.

2nd - Stapes and superior hyoid. Facial nerve, muscles of facial expression. Pouch = palatine tonsil.

3rd - Inferior hyoid. Glossopharyngeal nerve, stylophyrangeus, pouch = inferior parathyroid and thymus.

4th - laryngeal cartilage. vagus - superior laryngeal nerve, muscles of larynx and pharynx. pouch = Superior parathyroid, C cells of thyroid

6th - laryngeal cartilage. vagus - recurrent laryngeal nerve, muscles of larynx and pharynx.

Question 34

Face and nose and palate

Answer 34

Face
5 building blocks:
frontonasal prominence - form the forehead, bridge of the nose, upper eyelids and the centre of the upper lip.
two maxillary prominences - form the middle third of the face, the upper jaw and most of the lip and sides of the nose.
two mandibular prominences - form the lower third of the face, including the lower jaw and lip.

1st
depression in ectoderm on the ventral aspect of the head - stomadaeum - future mouth.
2nd
The five prominences fold around the stomadaeum to create the face.
3rd
prominences will fuse together to complete the face

Nose
1st
appearance of two ectodermal thickenings (nasal placodes) either side of the midline.
2nd
invaginate and form deep pits,1st the nasal pits, with the entrance of each pit being the future nostril.
A horseshoe-shaped ridge forms around the entrance to each nostril. The ‘arms’ are the medial and lateral nasal prominences.
3rd
The deepening nasal pits lie dorsal to the stomodaeum, separated by only a thin sheet of cells, the oronasal membrane.
This disappears, and the oral and nasal cavities become one continuous space.

Palate
1st
medial nasal prominences merge in the midline, separating the nostrils from the mouth to form:
philtrum of upper lip
midline component of the palate (the primary palate)
2nd
A palatal shelf grows from each maxillary prominence towards the midline.
3rd
They fuse with each other and
with the primary palate. Fusion creates the secondary palate and separates the nasal cavity from the oral cavity.

Question 35

anomalies of structural development:
cleft lip and palate, fetal alcohol syndrome, branchial cysts, sinuses and fistulae,
ectopic thyroid tissue and thyroglossal duct cysts.

Answer 35

2nd arch should obliterate clefts below but can be disordered
Anterior triangle - SCM is below cervical sinus that should be closed off
Cyst = enclosed
Sinus = communicates with skin
Fistula = connects skin with pharynx

Cleft lip
failure of the fusion of the medial nasal prominence and maxillary prominence.

Cleft palate
failure of the palatal shelves (hard palate) to meet in the midline.

If left uncorrected will cause difficulties with feeding and with speech development.

FAS
Failure of articular hillocks to ascend so ears are low
Other signs - flat mid face, smooth philthrum, small upper lip etc

Thyroglossal duct cysts
Embryonic pharynx has foramen caecum.
Junction between anterior and posterior tongue
Diverticulum descends and becomes thyroid gland
Duct connects tongue and gland
If it is not broken down it shows as lump in neck that will elevate when you ask to stick tongue out.
Isolated cyst or if duct remains it is connected with base of tongue so is fistula

Ectopic thyroid tissue
As it descends it can have sites of ectopic tissue.

Question 36

Describe autonomic nervous system
innervation to head and neck structures, general routes and effects
 The ganglia associated with the autonomic nerves supplying the head and neck.

Answer 36

Sympathetic:
1.Thoracolumbar portion of spinal cord (lateral horn).
2.head and neck region arises from T1/T2
3.Preganglionic ascend from thorax, up the sympathetic chain to reach the neck
3.Synapse in the superior and middle cervical ganglia
4.Postganglionic innervate target tissues by hitch hiking onto CCA 5a.Sympathetic to the eye & orbit then run with ICA,
ophthalmic artery & distal branches of Va
5b.Sympa to sweat gland on face and neck run with ECA.

Para:
Craniosacral outflow
The nuclei (collections of preganglionic para cell bodies) lie in the brainstem (in close proximity to nuclei of cranial nerves to which they will hitch hike)
4 head and neck ganglia - ciliary, pterygopalatine, submandibular, otic.
Reach by hitch hiking III, VII, IX and X.
Synapse except X
Postganglionic hitch hike onto branches (v small part) of the trigeminal nerve, to reach the target tissues.
For vagus travel into thorax and synapse at ganglia very close to target tissue.

Question 37

 Relationships to other anatomical structures such as blood vessels and cranial
nerves and points of vulnerability to damage or injury.

Answer 37

Post runs with CCA and then either ICA, ophthalmic artery, distal branches of Va
OR
ECA
So point of weakness due to dissection or aneurysm

Lung cancer can invade sympathetic trunk

Question 38

clinical signs and symptoms patients may present due to pathology

Link to MSK vertebral disc herniation

Answer 38

Horner’s syndrome:
Partial ptosis - LPS retracts upper eye lid - sympathetic only innervates smooth muscle which is small portion. Skeletal is oculomotor.
Miosis
Anhydrosis
Enophthalmus

Question 39

• Describe the pupillary light reflexes (direct and consensual) and interpret
abnormalities in this reflex

Question 40

Cranial nerves that carry parasympathetic fibres and nuclei and functions

Answer 40

1973

Edinger -westphal nucleus - occu- ciliary - sphincter pupillae which constricts pupil and ciliary muscle which fattens lens.

Dorsal motor nucleus - ganglia close to tissue - Mucosal glands & smooth muscle within respiratory & most of gastrointestinal tract. Cardiac muscle

Superior Salivary nucleus - pterygopalpatinea + submandibular ganglia - lacrimal gland, nasal and mucus glands and sublingual and mandibular glands.

Inferior Salivary Nucleus
- glosso - parotid gland

Question 41

Route of each para nerve in head and neck

Question 42

• Describe the anatomy (and nerve supply) of the external, middle and inner ear

Question 43

• Explain why referred pain from other head and neck structures can involve the ear.

Question 44

• Describe important anatomical relations, particularly of the middle ear e.g. facial
nerve, mastoid bone (air cells), pharyngotympanic tube and the complications that may arise as a result of their involvement with middle ear pathology.

Question 45

• Outline, with reference to the relevant anatomy, how the vibration created by sound
waves at the tympanic membrane is translated into an electric signal in the vestibulocochlear nerve.

Question 46

• Recognise disorders affecting the ear, listed below, and be able to explain and relate
key presenting clinical features to the anatomical structures involved
Pinna haematoma and perichondritis, otitis externa, acute otitis media and otitis
media with effusion, cholesteatoma, otosclerosis, presbycusis, vestibular neuritis
(vs labyrinthitis), Meniere’s Disease and Benign Paroxysmal Positional Vertigo

Question 47

• Explain the steps involved in examining the external ear, external auditory meatus and
tympanic membrane using an otoscope.
• Identify the features of a normal tympanic membrane as viewed during otoscopic
examination.
• Interpret the findings of Weber’s and Rinne’s test and list conditions that can cause
conductive or sensorineural hearing loss.

Question 48

• Name and identify the bones forming the walls of the orbit - look at notion, particularly in relation to fracture in orbital injuries

Answer 48

The inferior is the weakest - maxillary - fracture when there is direct impact - orbital blow out fracture
Medial wall is ethmoid bone - thin but with air cells that add strength - can become infected in acute sinusitis and break through and cause orbital cellulitis.

Orbital Blowout fracture
Sudden ↑intra-orbital pressure from trauma to orbit: fractures orbital floor [maxilla]
Orbital contents prolapse & bleeding into maxillary sinus
Muscles near orbital floor ‘trapped’ in fracture site
Entrapment of these tissues prevent upward gaze (+ other eye movements restricted)
Management - CT Orbit
Avoid nose blowing,
Avoid driving (until diplopia resolves)
In 1 week entrapment, diplopia & enophthalmos resolve as oedema ↓
Surgical repair 1-2 weeks post injury if symptoms persist

Question 49

• Describe the important anatomical relations of the orbit and orbital structures, their
blood supply (including the retina) and the implications for the spread of infection from the orbit to other structures (e.g. cavernous sinus, anterior cranial fossa, nasal cavity, paranasal air sinuses) and extension of injury from orbital trauma.

Answer 49

A series of holes at the apex of the orbit:
Optic canal - optic nerve + ophthalmic artery
Superior orbital fissure - CN 3, 4, 6, 5a and superior ophthalmic vein
Inferior orbital fissure - infraorbital nerve (branch of Vb) and the inferior ophthalmic vein.

Retina supplied by central retinal artery [branch of OA]
Also draws supply from the underlying choroid layer - Ciliary arteries (posterior and anterior) feed extensive capillary bed within choroid layer (choriocapillaries)

Central Retinal Artery Occlusion (CRAO)
Sudden painless loss of vision in one eye, developing over seconds e.g. due to embolus causing occlusion
Pale retina due to ischaemia. Macula = cherry red - thinnest part so underlying choroid accentuated due to ischaemia.

Question 50

• Describe the functional anatomy of the eye, part 1 in particular those structures allowing for the passage, refraction and focus of light onto the retina.
Eyeball

Answer 50

Eyeball:
Outer protective, tough, fibrous sclera. Attachment for extra-ocular muscles. Continuation of prick nerve dura.
Covering sclera is thin transparent layer of cells called the conjunctiva. Blood vessels run through.

Middle layer/ uveal tract - choroid, which continues anteriorly as the ciliary body and iris(thin diaphragm with central hole). The ciliary body (consisting of a ciliary process - blood vessels and muscle) connects the choroid with the iris. Sphincter and dilator pupillae form the iris and control the size of the pupil (central aperture of iris).

Posterior to iris is lens (refraction)- transparent biconvex structure
Proteins in lens can degrade - cataracts

Inner layer - retina
pigmented epithelial cell layer after choroid. Contains melanin - helps absorb scattered light, dec reflection, focus images onto retina.

neurosensory layer - senses light. Has photoreceptors (rods and cones). Photoreceptors convert light energy into electrical impulses.
The cones are responsible for high visual acuity and colour vision - in fovea which is centre of macula which is the centre of your vision. Visible on fundoscopy as slightly darker area, just lateral to the optic disc.
Dysfunction of one of 3 cones leads to colour vision blindness -inherited condition more frequent in males.
Rods - low intensity light. Peripheral parts.
Electrical impulses to optic disc which is the accumulation of retinal axons that leave the eye as the optic nerve - no photoreceptors - blind spot.

Question 51

Describe the functional anatomy of the eye, part 2 including the lacrimal apparatus, and
note in particular those structures allowing for the passage, refraction and focus of light onto the retina.

Answer 51

The eyelids are strengthened and given their shape by tarsal plates (dense bands of connective tissue) that contain tarsal glands (Meibomian glands) - oily secretions -lubricate edge of eyelids, mix with the tear film over surface of eye so tears don’t evaporate quickly.
Blocked = Meibomian cyst - lump within the eyelid.
Styes - infected hair (eyelash) follicle or sebaceous gland.

The lacrimal apparatus consists of lacrimal gland, lacrimal ducts and lacrimal canaliculi
The gland, secretes the lacrimal fluid (tears) - lies in a fossa on the superolateral part of the orbit.
Lacrimal fluid from the gland enters the conjunctival sac through lacrimal ducts and passes into the lacrimal lake at the medial angle of the eye.
From here the fluid drains into the lacrimal sac (S) before passing into the nasal cavity via the nasolacrimal duct (N).
The eye blinks when the cornea becomes dry and the eyelids carry a film of fluid over the cornea + sweeping dust across to the medial angle of the eye to be removed.

Question 52

refraction and focus of light onto the retina.

Answer 52

For light to focus on the retina it must be refracted.
The conjunctiva (and tear film), cornea, and humour within the eye all act to refract light.
The main refractor of the eye is the cornea
With very near objects, the light rays are more divergent and greater refraction beyond the capabilities of the cornea (which is fixed in curvature) is required.

Accommodation reflex:
Pupillary constriction to ensure that light from the near-object passes through the centre of the lens.
Convergence of the retinae of both eyes so focus on one object.
Contraction of ciliary muscle moves the ciliary body closer to the lens - pull of circular suspensory ligaments on the lens loosens.
Allows lens to become more biconvex (rounder).
Better focus of the near-object on the retina.

However, as we age the lens becomes dense, less elastic and more difficult to change shape. Ability to accommodate becomes impaired - presbyopia - glasses

Question 53

• Outline the production and flow of aqueous humour between the anterior and
posterior chambers - notion

Answer 53

The eyeball has three chambers, an anterior and posterior with aqueous humour.
Vitreous chamber most posteriorly with vitreous humour.

anterior chamber is the space between the cornea and the iris, and it communicates with the posterior chamber through the pupil.
The posterior chamber is the space between the iris and the lens. It is in this chamber that the ciliary body and processes are found, which secrete the aqueous humor filling both chambers.

Supports the shape of eyeball by the pressure it exerts + nourishment to the lens and cornea, which are avascular.

The aqueous humour drains through the irido-corneal angle (the space between anterior surface of the iris and posterior of the cornea) into the canal of Schlemm via trabecular meshwork and back in venous circulation.

Question 54

pathophysiology and presentation of glaucoma.

Answer 54

Glaucoma
Damage to optic nerve due to inc IOP - drainage of aqueous humour obstructed.
Humour should go from Irish-corneal angle to canal of Schlemm via a trabecular meshwork and subsequently back in the venous circulation.

Open-angle glaucoma
Problem - blockage in trabecular meshwork with age
Onset - slow and painless
Signs - raised IOP so loss of peripheral visual field and optic disc cupping. Also tonometry.
Treatment - topical to dec production eg beta blockers such as Timolol or trabeculectomy.

Close-angle glaucoma
Problem - irido-corneal angle is narrowed by peripheral edge of iris. Less common.
Signs - sudden onset of a painful red eye, blurred vision, halos around objects (due to corneal oedema), a fixed semi- dilated, oval-shaped pupil and nausea and vomiting. The eye will feel hard and tender to palpate through the upper eyelid.
Treatment - emergency.
diuretics (e.g. acetazolamide (dec production), muscarinic eye drops (e.g. pilocarpine - pupillary constriction, which helps open the angle) and strong analgesia. Iridotomy. Risk factors - Long-sighted middle aged or elderly people (with shallow anterior chambers).

Question 55

• Describe and explain with reference to the relevant anatomy common and
important (sight-threatening conditions) that involves the eye and/or its associated structures including: blepharitis; conjunctivitis, subconjunctival hemorrhage, glaucoma, and pre-septal and post-septal (orbital) cellulitis.

Answer 55

Blepharitis: inflammation of eye lid margin
causes: staphylococcus, Meibomian gland dysfunction
Crusting, dry eye lids, swollen, red
lid hygiene

Conjunctivitis - inflammation of conjunctiva
Viral aetiology
report eye feeling uncomfortable and ‘gritty’ (rather than painful) with accompanying tearing of the eye.
Highly contagious
Treatment is hygiene advice (washing hands/not sharing towels etc) + short course of topical chloramphenicol eye drops [reduces risk of secondary bacterial infection].
Conjunctivitis in the neonatal period -Infective organism such as chlamydia, picked up from the mother’s vaginal mucosa during birth. Systemic antibiotics (erythromycin).

Subconjuctival haemorrhage - painless, spontaneous

Orbital Septum: thin fibrous sheet separates intra-orbital contents from eyelid.
Barrier against infection spreading from eye lid region (pre-septal) into the orbital cavity (post-septal)
Peri-orbital cellulitis
Cause - bites, wounds infection
Painful, eye movements unaffected
Orbital cellulitis
Cause - Spread of infection from paranasal air sinus
Proptosis, dec + painful eye movements, dec visual acuity, life-threatening
Spread intracranially - Cavernous sinus thrombosis, Meningitis

Question 56

• Identify the normal anatomical features of the retina (on an image of a fundoscopic
view) and describe the appearance of the optic disc in papilloedema and glaucoma (optic disc cupping).

Answer 56

Cup to disc ratio increases as optic nerve cells are dying in glaucoma.
Papilloedema- swelling of both optic discs in your eyes due to increased intracranial pressure

Question 57

Relate your understanding of the anatomy and function of the eye and orbital
contents (extraocular muscles) to the steps involved in a clinical examination of the eye and the significance of abnormalities noted during this examination.

Question 58

Measuring Visual Acuity
And causes of dec

Answer 58

Snellen chart
6m distance - top of fraction
Bottom of fraction is the lowest line of text they can read from 6m.

Transparency of structures anterior to retina eg proteins degrade in lens, becomes opaque - cataract.
vitreous haemorrhage

Refractive ability of structures anterior to retina
e.g. irregularity of corneal surface (astigmatism) optic neuritis
Ability of lens to change shape (presbyopia)
Shape of eyeball

Retina (including macula) or optic nerve
e.g retinal detachment
age-related macular degeneration
optic neuritis
glaucoma

Use of pin-hole can help discern refractive vs non-refractive error. If visual acuity improves with pinhole then it is a refractive error.
only allows light to enter directly perpendicular to cornea and lens This light does not need to be refracted to be brought into focus on macula

Otherwise retina or optic nerve problem - need fundosclpy

Question 59

Describe the location and actions of the extra-ocular muscles and the consequences of interruption to their nerve supply (i.e. CN III, IV and VI palsies, and CN III and VII lesions).

Answer 59

Extra-occular muscles - run in line with orbital axis (not visual axis) - All insert into sclera
Each has antagonist that balances during resting gaze.
Visual axes remain aligned (conjugate gaze)
Visual axes do not remain aligned- diplopia

Superior Rectus -Elevates eyeball, intorts, abduct - SR inserts into superior anterolateral surface

Inferior Rectus - Depresses eyeball, extorts, adduct- inserts into inferior surface

Superior oblique - Intorts & depresses eyeball - Depressor action dominates when eye is positioned medially - inserts into superior surface (postero-laterally). Comes from trochlear

Inferior oblique - Extorts & elevates eyeball - Elevator action dominates when eye is positioned medially - inserts into inferior surface (postero-laterally)

Question 60

• Describe and identify the major features of the oral cavity including
the location and drainage of the salivary glands.

Answer 60

Lateral walls = buccinators
Roof = hard and soft palate
Floor = muscles, tongue, soft tissue
Begins anteriorly at oral fissure

Extends posteriorly to orophyrangeal isthmus - formed by anterior and posterior pillars (or arches or folds) of the fauces - palatoglossus (anterior) and palatopharyngeal (posterior) muscles from soft palate to tongue - on both sides.

These muscles contract during chewing which brings soft palate towards tongue so closing the oropharyngeal isthmus, ensuring that food remains in the oral cavity.

Between pillars lies tonsillar fossa which has palatine tonsil - circularly arranged lymphoid tissues of Waldeyer’s ring - inflamed in tonsillitis.

Question 61

Describe and identify the major features of the tongue pic on notion

Answer 61

muscular tissue covered in mucous membrane

4 intrinsic muscles - longitudinally, vertically and transversely; alter shape of the tongue, blend with the extrinsic muscles.

4 extrinsic - change the position of the tongue - protrusion (genioglossus - hypoglossal nerve), retraction and side-to-side movements.

Anchor to surrounding structures i.e. the hyoid bone and mandible below
Styloid process and soft palate above.

Anterior 2/3:
Taste - chorda tympani branch of facial nerve carried by lingual nerve
Sensory - lingual branch of Vc
Posterior 1/3:
Sensory and taste - glossophyrangeal (and supplies parasympathetic fibres to the parotid gland)

Motor overall - hypoglossal except palatoglossus which pharyngeal of vagus

Question 62

Finish Apply your under standing of anatomy to explain how we test the integrity of
cranial nerves IX, X and XII (i.e. the gag reflex, uvula deviation and protrusion of
the tongue) and what abnormalities are seen if a CN IX, XI or XII lesion is present.

Answer 62

test cranial nerve X - patient is asked to open their mouth and say ‘ahhh’. uvula inspected for any deviation to one side
Indicate weakness of the contralateral soft palate.

Gag reflex - tests
X, also IX which is the afferent limb of this reflex.

Hypoglossal nerve lesion - on one side cause the tongue, when protruded, to deviate towards the side of the lesion (“lick the wound”).

Question 63

• Describe the anatomical structure of the
pharynx -its boundaries, function and important anatomical relations e.g.
adenoids, pharyngotympanic tube, larynx.

Answer 63

Pharynx from base of the skull down to the level of C6.

3 parts:
nasopharynx -Boundaries -Base of skull to upper border of soft palate
C1, C2
Contains Pharyngeal tonsil (adenoids) + pharyngeal ostium of the auditory tube
Posterior extension of the nasal cavities, which open into it through two posterior nasal apertures (the choanae).

Oropharynx -from soft palate to the superior border of the epiglottis.
• Contains Palatine tonsils Which lie in between the palatoglossal and palatopharyngeal arches
Vertebral bodies of C2 and C3 lie posteriorly.

Laryngopharynx -
• Oropharynx to oesophagus • Epiglottis to cricoid cartilage
C4,C5,C6, buccopharyngeal fascia
• Contains Piriform fossa

Question 64

Describe the anatomical structure - muscles and nerve supply of the
pharynx

Answer 64

Externally, the walls of the pharynx consist of the circular superior, middle and inferior constrictor. Common posterior midline tendinous insertion - pharyngeal raphe
Propel food into the oesophagus.

Internally - 3 longitudinal muscles that act to shorten and widen the pharynx (and lift the larynx) during swallowing and speaking.

Motor - vagus nerve supplies all muscles of the pharynx and soft palate except stylopharyngeus, the one muscle supplied by CN IX

Sensory:
Nasopharynx-the maxillary branch of the trigeminal
Oropharynx (and pharyngotympanic tube) - glossopharyngeal nerve
Laryngopharynx- the vagus nerve

Question 65

• With reference to the relevant anatomy, describe pathology involving the pharynx
or structures within the pharynx and how they typically present e.g. pharyngeal
pouch, enlarged adenoids and pharyngotympanic tube.

Answer 65

Pharyngeal pouch - A posteromedial (false) diverticulum due to weakness between the two parts of the inferior constrictor (killian’s dehiscence).
Symptoms related to food material collecting in pouch or disruption of swallow
• Bad breath • Regurgitation of food • Occasional choking on fluids • difficulty swallowing
• Probably due to:
• Failure of the UOS to relax, abnormal timing of swallowing
This inc pressure in laryngopharynx so weakness in Inferior constrictor muscle so outpouching

Enlarged pharyngeal tonsils (adenoids)
• Block ET • Recurrent middle ear infections
• Snoring/sleep apnoea • Sleeping with mouth open
• Chronic sinusitis • Sore throat • Nasal tone to voice
Prominent in children but undergo atrophy. Recurrent inflammation = tonsillitis

URTI spread from pharyngotympanic tube in nasopharynx to middle ear

The piriform fossa is a potential site for foreign bodies (e.g. fishbone, chicken bone, etc.) entering the pharynx to become lodged
Also pharyngeal cancers.

Question 66

• Identify common pathology of the oral cavity namely tonsillitis, peritonsillar
abscess (Quinsy), and salivary gland pathology and how they typically present.

• Relate the phases of swallowing, to
key muscles, the cranial nerves involved and how dysfunction in swallowing may
present clinically.

Answer 66

Sialolithiasis
Most stones are in the submandibular glands(2x conc of Ca2+) , less than 1cm diameter stones.
Dehydration, dec salivary flow
Symptoms (eating stimulates)
• Pain in gland • Swelling
• Infection
Diagnosis- history, x -ray, sialogram

Tonsillitis- Inflammation of the palatine tonsils
Fever • Sore throat • Pain/difficulty swallowing • Cervical lymph nodes • Bad breath obstruct passage of air from nasal cavities to nasopharynx so mouth breathing and “nasal tone”.
Can also block the exit of the pharyngotympanic tube and lead to middle ear infections eg acute otitis media or otitis media with effusion.
• Viral causes (most common), Bacterial (40%) -strep pyogenes
Tonsillectomy from the tonsillar bed. Profuse bleeding (arterial blood supply is via the tonsillar branch of the facial artery).

Peritonsillar abscess
Severe throat pain • Fever • Bad breath • Drooling • Difficulty opening mouth
• Can follow from an un/partially treated tonsillitis or on its own (by aerobic and anaerobic bacteria)

Question 67

Describe the functional anatomy and important anatomical relations (e.g.
nasopharynx, pharyngotympanic tube) of the nose, nasal cavity and paranasal sinuses and relate their anatomy to their radiographic appearance.
Notion

Answer 67

Function
olfaction (smell), filtering and humidifying inspired air and allowing drainage of the secretions from the paranasal sinuses and nasolacrimal ducts.

External nose - cartilaginous part and bony part - frontal processes of the maxillae and two nasal bones.

Nasal cavity
Medial wall =nasal septum. Consists of the perpendicular plate of the ethmoid bone, septal cartilage and the vomer.
Lateral wall - superior, middle (both part of ethmoid) and inferior Concha (turbinates) - Slow down air flow + Increase surface area
Superior, Middle, Inferior Meatuses for Drainage, Connections with paranasal air sinuses, Nasolacrimal duct
Roof = frontal, sphenoid, ethmoid, nasal bone
Floor = maxilla and palatine bone

Regions:
oVestibule oRespiratory region oOlfactory region

Paranasal sinuses - Reduce weight of the skull + humidify
4 - maxillary, frontal, ethmoidal and sphenoid(not paired)
Air-filled spaces - bony cavities- lined with respiratory mucosa (ciliated pseudostratified columnar with goblet cells).
Drain into the nasal cavity via small channels (ostia) into a meatus. Middle meatus drains frontal, maxillary, anterior & middle ethmoid sinus. Inferior meatus drains the nasolacrimal duct.

Question 68

• Outline the neurovascular supply to the nose, nasal cavity and paranasal sinuses,
particularly the arteries supplying the nasal septum and their relevance to epistaxis and its management [this will be further supported by a short CTF tutorial on epistaxis during groupwork].

Answer 68

Nasal cavity
Rich blood supply for Humidification + Warming incoming air

The arterial supply is mainly from branches of the maxillary artery (sphenopalatine and greater palatine).
Anterior and posterior Ethmoidal arteries from ophthalmic artery (which is from internal carotid artery)
Branch of the facial artery - superior labial artery
Anastomosis of these arteries (5) occurs on the cartilaginous part of the septum known as Little’s Area.
Common site of most nosebleeds - medial (only 10% from sphenopalatine artery - higher pressure and posteriorly located so harder to reach to stop the bleed).

Nervous supply:
Trigeminal nerve - Ophthalmic branch, Maxillary branch
Paranasal sinuses - Va (Frontal, ethmoidal and sphenoid sinus) o Vb (maxillary sinus)

Question 69

• Explain common and/or important disorders involving the nose, nasal cavity and
paranasal sinuses such as rhinitis, epistaxis, nasal polyps, nasal fractures, septal haematoma

Answer 69

Rhinitis - Inflammation of the nasal mucosa. Can be Infective or Allergic
Symptoms - Nasal congestion - Rhinorrhea, Sneezing, Post nasal drip, Nasal irritation

Epistaxis -spontaneous or minor trauma e.g. nose picking, blowing the nose. Can have underlying systemic causes eg abnormal coagulation and connective tissue disorders.
Occur in the very young (2-10 years) or old (>50 yrs).
Management - pinching in front of bony bridge and leaning forward. If not, cauterise a visible bleeding point using silver nitrate. If can’t then anterior packing using nasal tampons. If bleeding still continues - posterior packing and surgical intervention e.g. embolisation, ligation of blood vessels.
“ABCs” (airway, breathing, circulation) monitored and blood tests taken to check Hb levels and clotting.

Nasal polyps
Benign swellings of the nasal mucosa usually in those >40 years old, M:F 2:1, bilateral
Symptoms - Nasal congestions, Rhinorrhea, Hypo- or Anosmia, Snoring, Post nasal drip –> cough
RED FLAGS!
- Unilateral polyp - Bloody discharge

Nasal fractures - 50% of all facial fractures, Lots of swelling, epistaxis
- X-rays not generally required
- Follow up in several days once swelling has gone
- Rare complications include CSF leak and anosmia

Septal haematoma - due to nasal trauma - blood collects between cartilaginous septum (in medial wall) and its perichondrium (which gives the blood supply). Lifts the perichondrium off the cartilage stripping away its blood supply - pressure of accumulating blood causes ischaemia of cartilage - if not drained in time irreversible necrosis of the cartilage can occur - “saddle” deformity - dip in dorsum

Question 70

• Describe the anatomical structures (including cartilages, muscles* and their nerve supply), boundaries of larynx

Answer 70

The larynx is between the hyoid bone and the trachea
vertebral level C4 - C6

3 subdivisions: the supraglottis, glottis and subglottis.

1.Hyoid bone
Epiglottis has attachment to hyoid bone
Has quadrangular membrane that connects it to arytenoid folds
Forms margins of entrance or aditus of larynx
Arytenoid folds connect to arytenoid cartilage (which is in posterior epiglottis) via quadrangular membrane
Thyroid cartilage (made up of two lateral plates meeting in the midline - laryngeal prominence) attaches to the hyoid bone (which is superior) by the thyrohyoid membrane.
From the arytenoids to the back of the thyroid cartilage are two folds of mucosa - lining interior of larynx - upper is vestibular fold (made of lower margin of quadrangular membrane)
Space between folds is rima glottidis.

2.Lower is vocal fold. Vocal fold contains the vocal ligament ( made of upper margin of cricothyroid ligament).

3.The cricothyroid membrane runs upwards from the cricoid cartilage

Question 71

function of the larynx.
Muscles

• Understand and explain the basic function of the larynx in phonation, swallowing,
respiration, and the cough reflex, particularly in relation to vocal cord position and
movement.

Answer 71

functions - ventilation and airway protection, cough to rapidly expel substances in the airways, production of sound (phonation), which is modified by the actions of the pharynx, oral cavity, lips, teeth and tongue.

Intrinsic muscles of the larynx - abduct and adduct true vocal cords by moving the arytenoid cartilage at the cricoarytenoid joint. This opens and closes rima glottidis. Open to allow air into lungs during inspiration. Close during swallowing.
Make an encircling sheet in the larynx.
Only one does abduction - posterior cricoarytenoid by rotating arytenoids outward. Without this there would be permanent adducted position.

Cricothyroid muscle is the only one that is external. It makes higher-pitched sounds by tensing (and slightly adducts) the true vocal cords. Has a tilting action of the thyroid cartilage on the cricoid cartilage.

Intrinsic muscles also attach to the epiglottis, and their contraction pulls down on the sides of the epiglottis so that it covers over the laryngeal inlet.
Work with longitudinal pharyngeal muscles and suprahyoid muscles which pull larynx upwards.
Food /fluids are directed away from the laryngeal opening as we swallow, into the piriform fossae.

Question 72

Blood and nerve supply of larynx muscles

Answer 72

The internal laryngeal nerve (branch of the superior laryngeal nerve) gives sensory to supraglottis and glottis.
External (also branch of superior) gives motor to cricothyroid muscle.
Recurrent laryngeal nerve innervates sensory to infraglottis. Motor to intrinsic laryngeal muscles.

Accompanied by arterial branches from the superior and inferior thyroid arteries respectively.

Question 73

• Apply your anatomical knowledge of this area to understand common pathology and dysfunction of laryngeal structures and their clinical presentation e.g. vocal cord palsies, laryngeal cancers, epiglottitis and croup.

Answer 73

Hoarse voice:
Laryngitis - inflammation of larynx involving vocal cords, History of URTI
Croup (young/infants)- URTI caused by a virus eg parainfluenza, affects the larynx and trachea - ‘barking’ / seal-like cough, stridor, resp distress, cyanosis. Give 1dose corticosteroids. If severe may also need adrenaline+O2.
Epiglottitis(2-6)- inflammation causing swelling of epiglottis and supraglottic tissues - dyspnoea, stridor, drooling. Give antibiotics(haem b)
Laryngeal oedema - risk to airway e.g. allergic rection or swallowed foreign body (choking)
Laryngeal nodule - benign growth on vocal cords due to voice overuse - rest
Laryngeal cancer e.g. squamous cell carcinoma on vocal cord

Nerve injuries
Damage to the superior laryngeal nerve - weakness of phonation (esp higher pitch) due to loss of cricothyroid muscle.

Recurrent laryngeal nerve complete injury - vocal cord on the affected side paralysed. Takes up a neutral (paramedian) position between ab and adduction. If unilateral - opposite cord is unaffected - compensates - hoarseness and a weaker cough.
If bilateral - rima glottidis is extremely narrow (not completely closed) - difficulties in breathing.

Left recurrent laryngeal nerve loops under the arch of the aorta before ascending back up in a groove between the oesophagus and trachea so can be affected by aortic arch aneurysms etc.
Right recurrent laryngeal nerve by right apical lung tumours. loops under the right subclavian artery.

Question 74

• Relate your understanding of laryngeal anatomy to its appearance when viewed
endoscopically (e.g. flexible nasendoscopy, intubation)

Question 75

SInusistis

Answer 75

Sinusitis (mainly maxillary - opening is high on the wall of the nasal cavity). Cause is viral infection of the nasal mucosae.
1. Inflammation of mucosa causes swelling, reduced cilia movement and increased mucosal secretions.
2. Ostia can become blocked
3. Fluid builds up in sinus - mucosal oedema
4. Can develop a secondary bacterial infection - Drainage from sinuses may be obstructed if oedema involves openings into the nasal cavity and Stagnant pool collects within the sinus. Moraxella catarrhalis are most common bacteria. Also Streptococcus pneumonia + Haemophilus influenzae,
Diagnosis:
o Recent URTI – symptoms worse after 5 days or lasting beyond 10
o Blocked nose and rhinorrhoea +/- green/ yellow discharge
o Pyrexia
o Headache/ facial pain (in area of affected sinus) - Worse on leaning
forward
Management: Self-limiting (1-2weeks), give analgesics, maybe antibiotics if secondary bacterial infection is suspected.
Complications - infections in the air cells of the ethmoidal sinuses may break through medial wall of the orbit - orbital cellulitis - sight threatening as they may involve optic nerve or intracranial structures.

Question 76

1. describe the imaging investigations available to investigate the GI tract and abdominal viscera including x-rays, fluoroscopy studies such as barium swallows, ultrasound, cross-sectional imaging such as CT and MRI, and angiography

Answer 76

Abdo X-rays:
A = Air - Pneumoperitoneum: CT > erect CXR > AXR
Rigler sign: bowel wall crisply and clearly defined due to gas on both sides
B = Bowel - Sigmoid volvulus: Coffee bean sign of large gas-filled viscus from pelvis to epigastrium. Normally positioned caecum
Caecal volvulus: Reverse C shaped viscus right side, Normal sigmoid
D = Dense structures & calcification
O = Organs & soft tissues
X = eXternal objects & lines & tubes

Barium swallow is a test of the pharynx, oesophagus, and proximal stomach.
Give patient barium to swallow and then use videofluoroscopy (continuous Xray viewed in real time on a screen).
Swallow test which can highlight problems with the stages of swallowing eg:
Impaired relaxation of lower oesophageal sphincter - Bird-beak or rat-tail stricture of distal oesophagus, Food residue in oesophagus
• Upper GI endoscopy has largely replaced it for the assessment of peptic ulcer disease and the evaluation of haematemesis.

Abdominal CT produces high resolution images of the abdomen (and can be further augmented with contrast) but high dose radiation.
Good understanding of sectional anatomy required.
Individual images from a CT scan can be reformatted and combined to produce a 3D representation of the scanned anatomy. Eg a virtual colonoscopy.

Abdominal MRI gives detailed and high contrast images of the abdomen without using radiation. Time-consuming process.

Abdominal ultrasound is cheap and portable, but it is very user dependant.
Commonly used to visualise the biliary tree (for gallstones and dilated bile ducts).

GI angiography • A way of visualising the vasculature associated with the intestines
• CT angiography has replaced conventional angiography for mesenteric vasculature

Question 77

4. compare and contrast the appearance of small and large bowel on an abdominal radiograph and describe the classical images of bowel obstruction.

Answer 77

Small Bowel
• Central position
• Valvulae conniventes - white lines passing across the full width of the bowel
• fluid or air

Large Bowel
• Peripheral position
• Haustra - incomplete lines across the bowel wall
• Transverse colon and hang down to pelvis
• Sigmoid colon can loop and be long
Faeces can be visible due to the slow transit time of the large bowel. Fluid or faeces.

Small bowel obstruction - CT first line imaging - Can identify the level and cause of the obstruction, whether bowel is strangulated
• However, what small bowel obstruction looks like on an Xray can be helpful -diameter greater than 3cm = obstruction
• Features of small bowel obstruction include the central position of gas-filled and distended loops of bowel.

Large bowel obstruction - CT - confirm diagnosis and localize location of obstruction, identify the cause’.
• Abdominal xray - colonic distension down to the level of the sigmoid colon as it is gaseous from organisms in faeces
small bowel dilatation, which depends on duration of obstruction and incompetence of the ileocecal valve
• diameter greater than 6cm (9cm for the caecum) = obstruction
• Since the large bowel tends to sit peripherally in the abdomen, it may be possible to determine the level of obstruction.
• The dilated colon is abruptly ‘cut-off’ at the level of obstruction.
Sigmoid volvulus can appear like a large coffee bean on abdominal x-ray, starting in the LIF pointing towards the RUQ.

Question 78

3. list the common reasons for requesting a plain abdominal radiograph

Answer 78

Position of iatrogenic items
Confirm ureteric stone identified on CT can be seen on xray, to use xray as follow up modality

Acute abdominal pain??

• Small or large bowel obstruction? - CT scan is first line for small bowel obstruction - Abdo xray may show volvulus in large bowel obstruction

• Acute exacerbation of IBD?? - useful for toxic mega colon with perforation - has a specific look on an abdominal x-ray with colonic dilation, oedema and pseudopolyps.

• Renal colic?? - CT now first line investigation - Abdo xray can be done to check to see if stone has passed - Renal calculi, vascular calcification and the calcification of the pancreas following chronic inflammation are all visible.

Bowel perforation can be determined from an erect chest x-ray. It will show free gas under the diaphragm.

Question 79

2. recognise the key structures and viscera in cross sectional images of the abdomen

Answer 79

CT scan- Features at various spinal levels - T12
• aortic hiatus of the diaphragm

L1 - transpyloric plane
• fundus of the gallbladder
• pylorus of stomach
• neck of pancreas
• superior mesenteric artery origin
• hilum of kidneys - left:above • right:below
L3
Umbilicus
Inferior mesenteric artery
L4
iliac crest
bifurcation of abdominal aorta

Question 80

5. explain the role of ultrasound and CT in the assessment of the patient with acute abdominal pain.
6. recognise the use of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) scans in investigation of the abdomen and identify key anatomical structures.

Answer 80

Colon cancer
CT + contrast - measure invasion + metastases
CT colonogram - with air insufflation and 3D analysis

Rectal cancer
MRI for staging and follow-up - Detailed anatomy to guide chemoradiotherapy and surgery

Crohn’s disease
Mouth to anus, transmural skip lesions, fistulas, abscesses
Ultrasound for screening
CT for acute abdomen
MRI for diagnosis and follow-up

Ulcerative colitis
Large bowel only, continuous Mucosal, toxic megacolon, CT for perforation

Question 81

• List the most common risk factors associated with head and neck cancers and most common cell type

Answer 81

Types of cancers considered HNCs - Lip/oral cavity, pharynx, larynx, nasal cavity/sinuses and salivary glands.
Majority of HNCs are squamous cell carcinomas

• Risk factors for HNCs:
 Male, older age (~60- 70), smoking, alcohol, betal nut chewing
 Pre-malignant changes e.g. white patches (leucoplakia) or red patches (erythroplakia) seen on tongue
 Specific risk factors to note - HPV virus in oropharyngeal cancers (In younger patients ~30-40 years), EBV in nasopharyngeal cancers, exposure to sunlight (lip cancers).

Question 82

• Describe the common initial manifestations (i.e. typical presenting signs/symptoms) of HNC, particularly those of the oral cavity, pharynx and larynx, and of thyroid cancers.

Answer 82

Presentation- depending on location of the cancer, the structure(s) involved and the extent of cancer spread.

Lip/oral cavity presentation
– Lump
– Pain (included referred pain to the ear)
– Fixation of tongue
– Problems swallowing (dysphagia)
– Pain on swallowing (odynophagia)
Larger tumours that do not respond to RT may need extensive surgery (hemiglossectomy or total glossectomy)

Pharynx (Presentation)
– Lump
– Pain (included referred pain otalgia)
– Problems swallowing (dysphagia)
– Pain on swallowing (odynophagia)
– Weight loss

Larynx (presentation)
– Dyphonia (voice change)- main feature
– Dysphagia
– Referred otalgia
– Glogus
– Neck lump
– Weight loss
– Cacexia
Larger tumours that do not respond to RT may need extensive surgery (laryngectomy)

Cervical lymphadenopathy due to cervical lymph node metastases ( neck lump)

Question 83

• Outline the typical further investigations required to determine the diagnosis and severity of a HNC

Answer 83

Clinical examination
biopsy of the lesion or neck lump - (fine needle aspiration for cytology or a core biopsy) under ultrasound guidance.
imaging (e.g. CT/MRI) - evaluates the extent of the primary cancer, involvement of other structures and lymph nodes
Endoscopic investigation for cancers involving the nasal cavity, pharynx and larynx - direct visualisation of the cancer and enable biopsy.

TNM staging

Early-stage cancers are treated by surgery or radiotherapy, while more advanced cancers may require surgery and adjuvant chemoradiotherapy.
Surgical approaches - microsurgical techniques using lasers to radical neck dissection where all ipsilateral lymph nodes, the spinal accessory nerve, internal jugular vein and sternocleidomastoid muscle are removed.

Question 84

• Describe the anatomy of the thyroid gland, its anatomical relations in the neck and the relationship between its blood supply and the nerves supplying the larynx and vocal cords.

Question 85

Recall the four types of thyroid cancers

Answer 85

Risk factors:
• radiation exposure
• Family history and certain inherited conditions (e.g. FAP)
• Young lumps or old lumps (<20 or >70yr olds) in thyroid glands are more likely to be malignant

presentation:
• lump (in the thyroid or neck nodal metastasis)
• Rarely have problems with thyroid status (not true for all thyroid lumps)
• Compressive symptoms- problems swallowing, feeling like they are being strangled
• Can have voice change

Types:
– PapillaryadenoCa(80%) – FollicularAdenoCa(10%) – MedullaryCa(5%)
– Anaplastic Ca (5%)

Question 86

Thyroid investigations and treatment

Answer 86

Thyroidectomy - • Hemi-thyroidectomy
• Sub-total thyroidectomy
• Total thyroidectomy
Potential for iatrogenic injury to superior laryngeal and recurrent laryngeal nerves
• Radioactive Iodine
• Radiothearphy/Chemothearphy

Question 87

And through self-study on the cervical plexus (supporting resources provided)
• Broadly describe the organisation and location of the cervical plexus, its key branches in particular the phrenic nerve, and the structures they innervate.

Question 88

Relate the appearance of the normal anatomical structures of the skull, facial
skeleton, brain, cerebellum and brainstem to their radiographic appearance
in common imaging modalities such as plain radiographs, CT and MRI.

Question 89

• Recognise important pathology i.e. blood (intracranial haemorrhages), fluid levels in
paranasal air sinuses, facial bone and orbital blow-out fractures.

Question 90

• Describe the advantages and disadvantages of (US, X-ray, CT and MRI).
which imaging is used first-line for different pathologies e.g. US for investigating thyroid disease and other neck lumps, CT for intracranial haemorrhages or orbital fractures, facial x-rays
for facial bone fractures.

Answer 90

Plain radiography is cheap, readily available and have relatively low radiation compared to CT.
Only helpful for visualising bony structures.

CT scanning - radiation dose involved is higher
provides 3-dimensional, cross-sectional views
Greater range of tissue densities are distinguishable - allows bone, soft tissue, and brain to be viewed in detail.
A “window” can be set while viewing CT images so certain tissues appear with greater clarity. Eg, a soft tissue window (to view most organs), a bone window etc.

MRI - detailed 3-dimensional, cross-sectional views
soft tissue areas and areas with fluid (CSF in ventricles) appear as varying shades of black - The soft-tissue and grey
detail seen with MRI is much better than with CT
uses magnetic fields and radio-waves
further investigate pathology identified by CT e.g. a tumour.
more expensive
much noisier,
much longer (up to 30 minutes).
not used as a first-line investigation in acute conditions (e.g. stroke).
contraindications due to the use of strong magnetic fields.