Week 1: CAI Flashcards
1
Q
What is the Entrance to Nasopharynx called?
A
Nasal Choanae
2
Q
What do the Upper Respiratory and Gastrointestinal Tracts share?
A
A common proximal pathway
3
Q
What is Choanal Atresia? Who is it most commonly seen in?
A
- Compromise in normal size of Nasal Choanae, can be unilateral/bilateral
- Most common in neonates as one of most common cause of nasal obstruction in neonates
4
Q
What is the separation between the nasal cavity and the oral cavity?
A
Bone - Hard Palate
5
Q
What is the Concha
A
Superior, Middle, and Inferior Concha = Bony shelves that project inferiomedially from lateral wall on both sides of nasal cavity
Create meatuses
6
Q
What are the nasal cavity meatuses?
A
Superior, Middle, Inferior Meatus - Spaces under each bony shelf (Concha)
7
Q
What is the function of the nasal cavity? What structures assist this function?
A
- Bony Concha have highly vascular mucosal tissue covering: Warms, humidifies, and filters air coming through
- Bony Concha create turbulent air flow through the nasal cavity due to their shape. Further assisting as extending time for air to be warmed and allowing it to trap particle matter as air flows
8
Q
What do the nasal cavity and paranasal sinuses do to sound?
A
Produces resonance in our voice
9
Q
What is a nasal polyp
A
- Soft, painless, non-cancerous growth on lining of nasal cavity/sinus
- Hang down like teardrops
10
Q
What causes nasal polyps to form? (5)
A
- Chronic conditions I.e. Asthma
- Recurrent infections
- Drug Sensitivities
- Allergies
- Immune Disorders
11
Q
What can Nasal polyps cause?
A
- Large polyps / groups of polyps can block nasal passages and lead to difficulty breathing
- Large polyps can result in loss of sense of smell
- Polyps can cause recurrent sinus infection as they can block sinus drainage
12
Q
What comprises the nasal septum?
A
- Septal Cartilage (most anterior)
- Ethmoid bone (posterior + superior)
- Vomer (bone) (posterior + inferior)
- Hard Palate sits underneath
13
Q
What bones make up the nasal cavity, not the nasal septum?
A
- Nasal Bone
- Maxilla
- Palatine
- Inferior Concha
- Superior + Middle Concha (part of Ethmoid bone)
14
Q
What is the main blood supply to the Nasal Cavity?
A
- Internal Carotid
* External Carotid
15
Q
What arteries supply the Nasal Cavity?
A
- Internal Carotid - Anterior + Posterior ethmoidal arteries
- External Carotid - Maxillary a. + Sphenopalatine a.
- Come together on anterior nasal septum at Little’s Area / Kiesselbach’s Plexus - Rich Anastomoses
16
Q
What area of the Nasal Anastomoses is the main origin of nosebleeds?
A
Little’s Area / Kiesselbach’s Plexus
17
Q
What sensory nerves innervate the nasal cavity? Include their divisions
A
- Olfactory Nerve (CN I)
- Trigeminal Nerve (CN V) - CN Va (Opthalmic Division) + CN Vb (Maxillary Division)
- Both are Cranial Nerves
18
Q
Where can CN Va pain refer to/from?
A
Opthalmic division pain can refer to/from frontal head (forehead)
19
Q
Where can CN Vb pain refer to/from?
A
Maxillary division of Trigeminal Nerve pain can refer to/from upper maxillary teeth
20
Q
What does the Olfactory Nerve sense? CN I
A
Smell
21
Q
What does anosmia mean?
A
Loss of smell
22
Q
What might a fracture of the cribriform plate result in?
A
CSF Rhinorrhoea - Leaking of intracerebral fluid through nasal cavity
Anosmia - Loss of smell if olfactory nerve endings damaged
23
Q
What is the cribriform plate of the nasal cavity?
A
Found between the nasal cavity and the brain. Bone that separates and where olfactory nerves travel through to innervate nasal cavity region
24
Q
How does the Nasolacrimal Duct drain into the nasal cavity?
A
Lacrimal sac - Nasolacrimal duct - Inferior concha - Opening of duct into inferior meatus
25
What are the parts that make up the Upper Respiratory Tract?
Nares, Nasal Cavity, Nasal Choanae, Nasopharynx
26
What are the structures making up the Upper Respiratory Tract?
* Superior, Middle, Inferior Concha and Meatuses
* Nasal Septum
* Nasal Cavity
27
What are the Mucosa Lined Regions of the Nasal Cavity?
* Nasal Vestibule region (Find hairs here, trap large particles)
* Olfactory region (smell)
* Respiratory region (lined with ciliated pseudostratified columnar)
28
What are the boundaries that make up the upper respiratory tract?
* Hard Palate
* Nasal Choanae
* Cribriform plate?
29
What are the functions of the Upper respiratory tract?
* Warms
* Humidifies
* Filters
30
Describe the Sensory Innervation of the nasal cavity and how this relates to pain referral
- Olfactory nerve (CN I)
- Two divisions of Trigeminal Nerve (CN V)
- CN Va (Ophthalmic) - Refers pain to/from Frontal Head
- CN Vb (Maxillary) - Refers pain to/from Upper Maxillary Teeth
31
What are the potential consequences of a nasal polyp?
* Difficulty Breathing
* Anosmia
* Recurrent infections
* Blocked sinus/nasolacrimal drainage
32
What are the major arterial branches which supply the nasal cavity, and where do most nosebleeds originate?
* Internal + External Carotids
| * Kiesselbach's Plexus / Little's Area
33
A 55 y.o. man presents to A&E and requires insertion of an NG (Nasogastric tube). What is the ORDER of structures the tube will pass through in order to get to the stomach?
Nares - Nasal Cavity - Nasal Choanae - Nasopharynx - Oropharynx - Laryngopharynx - Oesophagus
34
A 55 y.o. man presents to A&E and requires insertion of an NG (Nasogastric tube). What is the ORDER of structures the tube will pass through in order to get to the stomach?
Nares - Nasal Cavity - Nasal Choanae - Nasopharynx - Oropharynx - Laryngopharynx - Oesophagus
35
What are the Sinus Cavities?
* 4 Pairs of air filled cavities
* Frontal
* Ethmoid
* Maxillary
* Sphenoid - Quite deep
36
What is the sensory innervation of the sinuses?
* All, except maxillary sinus, innervated by Ophthalmic division (CN Va) of Trigeminal Nerve
* Maxillary Sinus innervated by Maxillary Division (CN Vb) of Trigeminal Nerve
37
What sinus regions are innervated by CN Va?
* Ophthalmic Region of Trigeminal nerve
* Frontal
* Ethmoid
* Sphenoid
38
What sinus regions are innervated by CN Vb?
* Maxillary region of Trigeminal Nerve
| * Maxillary sinus
39
What Sinuses drain into the Sphenoethmoidal recess of the nasal cavity?
Sphenoid Sinus
40
What Sinuses drain into the Middle Meatus of the nasal cavity?
* Frontal
* Ethmoid
* Maxillary (Upwards)
41
What Sinuses drain into the Inferior Meatus of the nasal cavity?
* Nasolacrimal
42
Where in the nasal cavity do the sinuses and ducts drain?
* Sphenoid - Sphenoethmoidal Recess
* Frontal - Middle Meatus
* Ethmoid - Middle Meatus
* Maxillary - Middle Meatus
* Nasolacrimal Duct - Inferior Meatus
43
How does the Maxillary Sinus drain into the nasal cavity?
* Upwards against gravity
| * Via Hiatus Semilunaris
44
What in the oral cavity has very close relations to the maxillary sinus?
The floor of the maxillary sinus is in close relations to the upper maxillary teeth. Can affect drainage in cases.
45
What might poor drainage of the maxillary sinus lead to?
* Inflammation
* Infection
* Sinusitis
46
What issue can arise within the maxillary sinus?
An Extra bony septa that originates from the floor of the maxillary sinus (maxillary tooth) region into the sinus. Can find collections of fluid within the cavities formed
47
To what surgical relevance is the sphenoid sinus?
* Sphenoid Sinus is closely related to the Cranial Cavity
* Can be used for minimally invasive surgical approaches to the pituitary gland
* Through Nares, Nasal Cavity, Sphenoid Sinus, Can reach Pituitary
48
What separates the ethmoid sinus and the bony orbit?
Lamina Papyracea
49
What can occur if there is persistent infections in the ethmoid sinus?
* May erode + Spread infection through Lamina Papyracea into the bony orbit
* Causes Periorbital Cellulitis
50
Describe the position and routes of drainage of the sinuses and the Nasolacrimal duct
* Sphenoid sinus (superior to superior meatus) - Drains into sphenoethmoidal recess
* Frontal, Ethmoidal, Maxillary sinuses - Drain into Middle Meatus
* Nasolacrimal Duct - Drains into Inferior Meatus
51
Which Sinus drains against gravity, and why is this clinically relevant?
Maxillary sinus
| Poor drainage may result in inflammation, infection, sinusitis
52
How might an infection in one of the sinuses lead to an infection around the eye (periorbital cellulitis)
Persistent infection in ethmoid sinus may erode through the lamina papyracea, spreading infection into the bony orbit.
53
What are the paranasal sinuses lined with?
Respiratory epithelium, ciliated pseudostratified columnar epithelium. Produces mucus which need to drain into nasal cavity. If have virus/allergy lining can become inflamed, increasing fluid production
54
Outline the basic structure of the Ear
* External Acoustic Meatus
* Tympanic membrane
* Middle ear - Pharyngotympanic tube stems off to join nasopharnyx directly here
* Inner ear
* Internal Acoustic Meatus leading CN VIII (Vestibulocochlear) to the Intracranial Cavity
55
Within which area of the skull does the ear sit within?
Petrous portion of temporal bone - Ear bits protected and embedded
56
What is the ear divided into?
* External ear
* Middle ear
* Inner ear
57
What is the sensory innervation of the external ear?
* Auricle/pinna, external auditory meatus, tympanic membrane from both Cranial & Somatic Nerves
* C2 + C3
* CN Vc (3rd division of trigeminal nerve)
* CN VII & CN X (vagus nerve)
58
What is meant by referred pain?
If same nerve innervates multiple area, if one area that that nerve innervates perceives sensory stimulation, may perceive pain or stimulation is any of the other area that that nerve innervates.
59
What are the patterns of sensory innervation of the external ear? What does this mean in terms of referred pain?
* Referred pain to the ear can be from:
* CN Vc - Mandible & Mandibular teeth
* CN Vc - Temporomandibular (Jaw) joint (TMJ)
* CN X - Laryngopharynx
* CN X - Larynx
* CN X - Cardiac
60
What is the Auricle/Pinna made up of?
* Formed of elastic cartilage covered with skin, and a fleshy lobule
* Helix
* Antihelix
* Concha
* Lobule
* Tragus (the goat)
* Antitragus
* External Acoustic Meatus
61
Describe the function of the structure of the Auricle/Pinna/External Ear?
The shape of the ear captures soundwaves and directs them to the ear. Allows to hear things and localise the direction which they come from
62
What must you do if a patient presents with an auricle/pinna infection? Why?
- Conduct systematic examination of all nodes in the pericranial cervical line, down jugular and supraclavicular. To check if infection has spread
- Infection can result in abscess formation and spread to local node groups
63
Describe the External Acoustic Meatus Structure
* Anterioinferior angled tube/passage 2/3 cm long met by tympanic membrane
* S-shaped in an adult
* Laterally Cartilaginous transforms to Bony Medially where it is embedded within the petrous (hard) portion of temporal bone
* Contains modified sweat glands that produce cerumen (wax)
64
What is inflammation of the EAM called?
Otitis Externa
65
Describe the sensory innervation of the EAM
* CN Vc - Mandibular division of Trigeminal cranial nerve
* CN X - Vagus cranial nerve
* So if have otitis externa may get referred pain to any area where these nerves innervate
66
What is an otoscope?
Device through which light is shone and image magnified to inspect the external acoustic meatus and tympanic membrane.
Adult and child ear examined differently.
67
How do you examine an adult ear? How does this differ from child ear?
* Using an otoscope
* Pull Pinna Posterior + Superiorly in order to straighten EAM and examine
* Pull Pinna Posterior +/- Inferiorly
68
What anatomical structures compose the external ear, and what nerves innervate this area?
* Formed of elastic cartilage covered with skin and fleshy lobule
* Helix, Antihelix, Concha, Lobule, Tragus, Antitragus, External Acoustic Meatus, Tympanic Membrane
* Nerve innervation = C2 + C3, CN X, CN VII, CN Vc
69
What are the common areas that pain can refer to / or from the ear?
- CN Vc = TMJ - Temporomandibular join, Mandibular teeth, Mandible
- CN X = Cardiac, Laryngopharnyx, Larynx,
70
Describe the structural differences between the EAM of an adult and child and how this impact examination
* EAM of an adult is directed anterioinferiorly and S-shaped. Due to being embedded in the temporal bone. Requires otoscope examination with pinna pulled posterior and superiorly to straighten EAM
* EAM of a child is disproportionate, to get a clear view otoscopic examination requires auricle pulled posterior and inferiorly.
71
What is the Cone of Light in Otoscope examination of the Tympanic membrane?
* Light reflecting from the otoscope off the tympanic membrane
* In healthy individuals will always point anteriorly and inferiorly
* As tympanic membrane is concave
72
Describe the structure of the Tympanic Membrane
* Thin drum like membrane, concave shaped
* Consists of Malleus bone pointing Posterior & Inferior
* Umbo at end of Malleus
* Flaccid part (Superior)
* Tense part (Inferior part)
* Cone of light pointing anterior and inferior
* May see Chorda Tympani in upper 1/3
73
What is the Chorda Tympani?
Nerve branch which peels off Cranial Nerve VII (Facial Nerve) passing over Tympanic Membrane towards the Tongue. Responsible for bringing taste to anterior 2/3 of tongue.
74
How can Otitis externa/media affect the tympanic membrane?
* Increased concavity
* Bulging convexity
* Visible red inflammation
* Green suppuration (pus)
* Extreme case - Tear/Hole in TM = Ruptured eardrum
75
Describe the Layers of the Tympanic Membrane
- Outside layer - Skin
- Middle layer - Mesoderm
- Inside layer - Respiratory epithelium
- Each layer brings its own nerve supply from tissue embryologically derived from
76
Describe and explain the nervous innervation of the Tympanic membrane
* As outer and inner tympanic membrane layers are derived from different embryological tissues, have own nerve supplies.
* Outer Tympanic membrane innervated same as EAM: CN X (vagus nerve) + CN Vc (Mandibular Division of Trigeminal nerve)
* Inner Tympanic Membrane innervated by CN IX (9) Glossopharyngeal nerve
77
Describe pain referral from the Inner Tympanic Membrane
Innervated by Glossopharyngeal Cranial Nerve (CN IX). Pain referral to/from Pharynx
78
Describe pain referral from Outer Tympanic Membrane
* Innervated by CN Vc (Mandibular Division of Trigeminal Nerve) - Pain refers to/from Mandible, Mandibular teeth, Temporomandibular joint (TMJ)
* And CN X (Vagus Nerve) - Pain refers to/from Laryngopharynx, Larynx, Cardiac
79
What cranial nerve carries sensory from ALL portions of the Pharynx, Middle Ear, Auditory Tube & Inner side of Tympanic Membrane?
CN IX - Glossopharyngeal Nerve - Cranial Nerve 9
80
What is the cone of light on the tympanic membrane and what does this tell you?
- Cone of light is reflection of otoscopic light on the concave tympanic membrane
- Points anterior and inferior - Helps to orient what ear looking at if an image
81
How does the middle ear communicate with the pharynx - What clinical implication does this have?
* Communicates via auditory tube from middle ear to nasopharynx
* Infections in the throat may spread to the ear or vice versa.
82
Describe the layering of the tympanic membrane and why this is important?
Outer to Inner layer: Skin, Mesentery, Respiratory epithelium. This is important as it creates a barrier to protect the middle and inner ear. Functional differences in the ear.
83
Why might you think you have a 'sore throat', when actually it's a middle ear infection that's causing the pain?
The inner tympanic membrane is innervated by CN IX which also supplies the pharynx. Thus referred pain may be felt in the throat when there is inflammation in the middle ear.
84
What are the Ossicles of the Middle ear?
- Tiny bones including:
- Malleus (Pushes into tympanic membrane)
- Incus
- Stapes (Sits above oval window)
- Linked by Synovial Joints
85
Describe the functions of the Middle Ear?
* Links the tympanic membrane to the oval window
* Amplify signal from large tympanic membrane to small oval window
* Contains Mobile Synovial joints located between the ossicles.
* Ligaments prevent dislocation
86
What is the oval window?
Opening into the inner ear
87
What pathology can occur to the Mobile synovial joints of the ear?
- Can dislocate or be subject to any synovial joint disease type
- Become more stiff with age
88
Describe the cause conductive hearing loss
Damage to ossicles or middle ear disease
89
What muscles are found in the middle ear? Describe their functions
* Tensor tympani - Pulls tympanic membrane medially (taut) to reduce force/amplitude or vibrations
* Stapedius - Pulls Stapes bone & limits its range of movement in response to large vibrations (loud noises)
* Work to protect ear from loud noises and damage by limiting amount that bones vibrate / oscillatory range of ossicles.
90
Describe the Tensor tympani muscle
* Found in middle ear
* Originates in bony canal above pharyngotympanic tube . Inserts into neck of malleus.
* Pulls tympanic membrane medially (taut)
* Reduces force/amplitude of vibrations
* Nerve supply = CN Vc
91
Describe the Stapedius Muscle
* Found in middle ear
* Passes from pyramidal eminence to Stapes bone
* Pulls Stapes & limits its range of movement in response to large vibrations (loud noises)
* Nerve supply = CN VII (facial nerve)
92
What is the relevance of the nerve supply to the Stapedius in relation to Facial Nerve damage
* Facial nerve (CN VII) innervates the Stapedius muscle within the inner ear which functions to limit the oscillatory range of the Stapes bone to limit large vibrations.
* Damage to facial nerve may damage ability to filter out loud sounds/noises
* Can cause HYPERACUSIS - Sensitivity to loud sounds, can exacerbate to extent where loud noises are painful/uncomfortable
93
What is the relevance of the nerve supply to the Stapedius in relation to Facial Nerve damage
* Facial nerve (CN VII) innervates the Stapedius muscle within the inner ear which functions to limit the oscillatory range of the Stapes bone to limit large vibrations.
* Damage to facial nerve may damage ability to filter out loud sounds/noises
* Can cause HYPERACUSIS - Sensitivity to loud sounds, can exacerbate to extent where loud noises are painful/uncomfortable
94
What are the 6 walls of the Middle ear?
- Anterior - Carotid wall
- Superior - Tegmental wall
- Inferior - Jugular wall
- Lateral - Membranous wall
- Medial - Labarynthine wall
- Posterior - Mastoid wall (Mastoid aditus (opening) to mastoid air cells)
95
Describe the Chorda tympani nerve
- Peels off the Facial nerve, CN VII, passes through upper 1/3 of tympanic membrane and towards tongue
- Carries taste sensation from anterior 2/3 of tongue
96
What can happen to Chorda tympani if Tympanic Membrane ruptures?
- Can damage the Chorda Tympani resulting in loss of taste in anterior 2/3rds of ipsilateral tongue
97
What is the Semicircular Canal? What is the relevance to the Middle ear?
- Part of inner ear
- Responsible for balance in Vestibular system
- Can see outline of it on Mastoid (posterior) wall of Middle ear. A close relation. Facial nerve also bulges here
98
What is the promontory?
Bulge of the cochlea seen on labarynthine wall of middle ear
99
What is Mastoiditis?
* Infection of the mastoid air cells usually spreads from middle ear infections (otitis media) through posterior mastoid wall.
* Treatment not easy, some cases will persist / return
* If mastoid bone severely infected can cause hearing loss and more extremely Cerebral abscess/Dural Venous Thrombosis/meningitits
100
What are possible complications of mastoiditis?
Cerebral abscess, dural venous thrombosis, meningitis, hearing loss
101
Describe the Pharyngotympanic/Eustachian/Auditory tube
* From middle ear into nasopharynx
* Drains middle ear epithelial secretions (respiratory mucosa) and plays a role in pressure equalisation
* Proximal 1/3 Bone (embedded in petrous temporal bone) & Distal 2/3 Cartilage (trumpet shaped)
* Muscles involved in opening of the distal end of the tube
102
Explain the Opening of the Pharyngotympanic/Eustachian/Auditory tube
* Distal end of Pharyngotympanic tube is cartilaginous, quite flexible, usually collapsed on itself and close
* Opened when swallowing by 3 muscles:
* Tensor veli palatini (from palate toward bottom of tube)
* Levator veli palatini (soft palate to bottom of tube)
* Salpingopharyngeus (Stretches from tube to pharynx)
* Swallowing contracts these muscles which pull on distal tube and open it allowing fluid drainage to nasopharynx to be swallowed.
103
What is the opening of the Pharnygotympanic tube surrounded by?
Tubal tonsil tissue, also lymphatics
104
How can an Upper Respiratory Tract Infection spread via the Pharyngotympanic Tube?
- Throat infection can travel up the tube into the middle ear and cause infection spread
105
What clinical issues can arise in the middle ear?
* Otitis Media - Acute infective (suppurative - Produces pus)
* Glue Ear - Chronic persistent build up of mucoid fluid due to blockage of pharyngotympanic tube
106
Describe Otitis media
* Acute infective (suppurative - if pus produced)
* Often due to infection spread from nasopharynx to middle ear
* Pus accumulates in middle ear - Pain & swelling of tympanic membrane
* Perforation of membrane can occur & provide relief but affects hearing until heals.
107
Describe Glue Ear
* Chronic persistent build up of mucoid fluid / mucus in middle ear due to blockage of pharyngotympanic tube
* Causes conductive hearing loss as 'gluing' ossicles together in thick mucus
* Mostly affects young, can get speech and development problems
108
Why does Glue ear affect the young more?
Due to the shape of the Eustachian tube in the young... More horizontal and straight in a child compared to adult. Not as good at draining contents out of middle ear.
109
What is the result of Pharyngeal Arch 1 defects?
* Additional external acoustic meatuses (small non-functional) in front of pinna / anterior to trigs
* Auricular sinuses/cysts
* Ear malformations
* Treacher Collins Syndrome
110
Describe Treacher Collins Syndrome (5)
* Caused by Early embryological Pharyngeal Arch 1 defect
* Small, Underdeveloped (Hypoplasia) mandible
* Incus + Malleus bones are not developed well - Hearing issues
* Underdeveloped muscles of mastication
* Underdeveloped auditory tube and middle ear tissues
111
What can you find on Inspecting Ear & EAM?
* Blood
* Blockage
* Polyp
* Vesicles (Ramsey-Hunt Syndrome)
* Infection
* Secretions
112
Explain Ramsey-Hunt Syndrome
* Caused by reactivation of chickenpox virus, stays dormant in body nerves after initial infection cleared. Sometimes reactivates.
* Cardinal Symptoms: Painful red rash w/fluid filled blisters on/in/around ear + Facial weakness/paralysis as affects facial nerves.
113
What Clinical Examinations can be used to test the cochlear portion of Cn VIII (Vestibulocochlear nerve)?
* Rinne
| * Weber
114
What is involved in the Rinne Clinical Examination for Cochlear portion of CN VIII
* Vestibulocochlear nerve
* Strike tuning fork against hard surface for vibration
* Place on mastoid process behind ear, until not heard
* Move over ear canal, until not heard.
* Positive test - Normal - AC > BC
* As air conduction through ossicles is better than bone conduction
* Negative test - BC > AC - Conductive hearing loss
115
What is involved in the Weber Clinical Examination for Cochlear portion of CN VIII
* Vestibulocochlear Nerve
* Strike tuning fork and place on forehead
* No lateralisation - Normal - sound equal on both ears
* Conduction deafness - Sound loudest in affected ear
* Sensorineural deafness - Problem with nerve, sound loudest in unaffected ear
116
What early embryological tissues are responsible for ear formation?
* Pharyngeal arch 1 - Malleus & Incus
* Pharyngeal arch 2 - Stapes
* The first cleft - External Acoustic Meatus
* The first pouch - Middle ear and Pharyngotympanic tube
117
How does the embryo's first cleft and first pouch development explain the TM's structural organisation?
* Ectoderm of 1st cleft
* Endoderm of 1st pouch
* = Tympanic membrane with some mesoderm between
118
What is the pharynx?
* Muscular fascial tube that hangs from base of skull to where oesophagus begins
* Connects nasal & oral cavities with larynx & oesophagus
* Composed of Nasopharynx, Oropharynx, Laryngopharynx
* Can undergo perstalsis
* Has 3 pharyngeal constrictor muscles lined by continuous fascia and mucosa
119
What travels through the pharynx?
Air, food, liquid, mucous
120
What are the relations of the Nasopharynx?
* Nasal cavity
* Posterior to Nasal Choanae
* Auditory tube from Middle ear
* Lower border of soft palate
* Superior to Oropharynx
* Anterior to Body of C1 vertebrae
121
What muscles comprise the Soft Palate?
* Tensor veli palatini (stretches palate)
| * Levator veli palatini (lifts palate)
122
What do the Tensor VP & Levator VP do to the auditory tube when you swallow?
Pull on distal ends of auditory tube causing it to open to allow middle ear to drain its continual mucus productions into nasopharynx
123
What prevents food travelling up nasopharynx into nasal cavity?
* Tensor veli palatini and Levator veli palatini soft palate muscles contract to stretch and lift palate backward against nasopharynx to completely block the passageway
* Hence, separating nasopharynx from oropharynx during swallowing
124
What are the relations of the oropharynx?
* From Palatal arches --> C2/C3
* Upper border to soft palate --> Base of tongue
* Large amounts of lymphoid tissue here (tonsils)
125
What are the relations of the Laryngopharynx?
Larynx ---> C3-4/5/6
| Base of tongue --> Cricopharyngeus muscle
126
What happens as you move down the pharynx (2)
- Regions get larger
| - Transition from pseudostratified columnar epithelium to stratified squamous epithelium
127
Describe the sensory innervation of the Pharynx
* Nasopharynx - CN Vb + CN IX
* Oropharynx - CN IX
* Laryngopharynx - CN IX + CN X
128
Describe the sensory innervation of the Nasopharynx
CN Vb + CN IX
129
Describe the sensory innervation of the Oropharynx
CN IX
130
Describe the sensory innervation of the Laryngopharynx
CN IX + CN X
131
What cranial nerve carries sensory from ALL portions of the Pharynx, Middle Ear, Auditory Tube & Inner side of TM?
CN IX / Cranial nerve 9 / Glossopharyngeal nerve
132
What are the major divisions of the pharynx?
* Nasopharynx, Oropharynx, Laryngopharynx
133
What are the major anatomical boundaries of the Pharynx?
Cervical vertebrae, Nasal cavity, oral cavity, soft palate, larynx, epiglottis
134
How does the pharynx communicate with the middle ear, why is this clinically relevant?
Via the auditory tube. Relevant as infections can spread to and from the middle ear and the nasopharynx.
135
What Muscles comprise the Pharynx? (9)
* Superior Constrictor
* Middle Constrictor
* Inferior Constrictor
* Cricopharyngeus - Inferior to Inferior Constrictor
* Longitudinal Muscles:
* Stylopharyngeus - From styloid process into pharyngeal musculature
* Tensor veli palatini
* Salpingopharyngeus
* Levator veli palatini
* Palatopharyngeus
136
What is the role of the Cricopharyngeus muscle?
Acts as the True Upper Oesophageal sphincter. Must relax to let food pass into oesophagus
137
What is the role of the muscles in the Pharynx?
* Superior, Middle, Inferior Constrictor contract in a peristaltic manner, reducing the diameter of pharynx tube in order to push food downwards into oesophagus.
* Cricopharyngeus relaxes
* Drop in intrapharyngeal pressure to allow food to progress downwards
138
What is the motor nerve supply to the muscles of the Pharynx?
* CN X (vagus)
| * Exceptions: Stylopharyngeus (CN IX), Tensor veli palatini (CN Vc)
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What are the attachments of the Superior Constrictor of the Pharynx?
Pterygomandibular Raphe
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What are the attachments of the Middle Constrictor of the Pharynx?
* Hyoid Bone
| * Stylohyoid ligament
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What might exceptionally long styloid processes lead to?
* May press into soft tissues of the pharynx and affect swallowing --> Dysphagia
* May compress facial nerve and cause facial pain
* Can also cause carotid artery compression
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What are the attachments of the Inferior Constrictor?
Thyroid cartilage
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What are the attachments of the Cricopharyngeus?
Cricoid cartilage
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What is the Midline Raphe?
* Similar to a long tendon
* Central attachment of all pharyngeal constrictors posteriorly
* Pharyngeal constrictors overlap each other
* Midline Raphe starts from base of skull to where inferior constrictor ends
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Note the changes in the directionality of the Pharyngeal constrictors. Why is there a weak spot between the inferior constrictor and the cricopharyngeus
* Superior C relatively horizontal
* Middle C relatively vertical
* Inferior C more diagonal
* Cricopharyngeus - Very Horizontal
* The change in directionality creates a weak spot, also less fibres in this area while changing.
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Where is the 'weak spot' in the Pharyngeal Muscles? What clinical relevance is this?
* Posteriorly, at end of midline Raphe between Inferior Constrictor and Cricopharyngeus
* Can have a hernia of the internal lining of pharynx backward through weak spot and create mucosal pouch = Zenker's diverticulum / Pharyngeal diverticulum
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What are complications of Zenker's Diverticulum
* Pouch created by herniation of mucosal pharyngeal lining posteriorly
* Excessive build up of material may cause intermittent compression of oesophagus sitting anterior to diverticulum
* Periodically cough up decomposed food from pouch
* Chronic halitosis/Bad breath
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What is the Piriform Fossae? What is its role in swallowing?
- Recess between larynx and lateral thyroid cartilage
- Extra safety measure to prevent food going into larynx, space around sides of closed larynx so food passes around larynx rather than over top of it. Reducing risk of aspiration of food into lungs
* However, food may get lodged and stuck in this area
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What is the Vallecula?
- Midline depression, behind base of tongue and superior to epiglottis.
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What is the motor nerve supply to the Stylopharyngeus Longitudinal muscle of the pharynx?
* CN IX
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What is the Motor nerve supply to the Tensor veli palatini?
CN Vc
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What is the function of the Salpingopharyngeus?
* Arises from auditory tube
* Helps open tube on swallowing
* EQUALISE PRESSURE
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What are the longitudinal muscles of the pharynx? What do they do?
* Stylopharyngeus
* Salpingopharyngeus
* Tensor veli palatini
* Levator veli palatini
* Palatopharyngeus
* All muscles contract to help elevate pharynx, some change shape of soft palate to seal nasopharynx from oropharynx + help to shorten pharynx overall.
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What three muscles act upon the distal portions of the auditory tube, and what do they cause when they contract?
* Tensor veli palatini (CN Vc)
* Levator veli palatini (CN X)
* Salpingopharyngeus
* Cause opening of the auditory tube to drain fluid and also move soft palate upwards and backwards agains the nasopharynx in order to block passage of food into nasal cavity
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Describe the anatomical locations of the vallecula and piriform fossa - why are these both clinically relevant?
- Vallecula is a midline depression at the base of the tongue and superior to the epiglottis.
- Piriform fossa is a mucosal lined recess part of pharynx, between larynx and lateral thyroid cartilage.
- This are areas where food can get stuck/lodged.
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What are the Palatoglossal and palatopharyngeal arches?
Muscles which hang down from soft palate and can be visualised in posterior wall of oral cavity. Larger arch = Palatoglossus muscle, Smaller arch = Palatopharyngeus muscle. Called arches as covered with mucosa.
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Where are the Palatine Tonsils
Embedded between Palatoglossal and Palatopharyngeal arches
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What does the levator veli palatini muscle do on contraction?
Elevates the soft palate
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What does the levator veli palatini muscle do on contraction?
Tenses the soft palate tight, as inserted on lateral sides and pulls upwards and laterally
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What does damage to CN X / CN Vc motor fibres lead to?
Possible ipsilateral (one sided) soft palate paralysis
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What structures can be found on the posterior wall of the oral cavity?
Soft palate, Palatoglossal arch, Palatopharygneal arch, Uvula (dangly bit), Palatine Tonsils between arches on either side.
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If a patient HAS sensation but unilateral / no contraction of soft palate. What does this indicate?
* CN X lesion (Motor loss)
| As this nerve is what brings motor supply to this region
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What does the gag reflex test?
* Sensory arm of the glossopharyngeal nerve
| * Motor arm of the vagus nerve
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If a patient has NO sensation (and thus no setting off the gag reflex) when touching a side of the pharynx. What does this mean?
CN IX lesion (Sensory loss)
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How do you elicit the gag reflex?
Touch pharynx on both sides to check sensory and motor arms of nerves.
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Why must you inspect the soft palate and oropharynx for asymmetry when eliciting gag reflex?
If lesion in vagus nerve + loss of motor innervation to part of soft palate. May have some atrophy of muscles.
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Why must you inspect the soft palate and oropharynx for asymmetry when eliciting gag reflex?
If lesion in vagus nerve + loss of motor innervation to part of soft palate. May have some atrophy of muscles.
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What is Waldeyer's Ring, and why is it present where it is?
* Ring of lymphoid tissue present in nasopharynx and oropharynx (throat)
* Because these areas are exposed to the outside environment quite readily so can act as entrances to infection.
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What composes Waldeyer's Ring?
Groups of tonsils
* Pharyngeal (Adenoid) - Back of nasopharynx
* Tubal - Around pharyngotympanic tube opening
* Palatine - Embedded between Palatoglossal and Palatopharyngeal arches
* Lingual - Base of tongue
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What happens if Adenoid tonsils enlarge?
* May enlarge to extent where pharyngotympanic tube is blocked, causing chronic ear infections
* May obstruct nasopharynx / nasal cavity - Breathing issues, snoring, sleep apnoea, uncomfortable feeling when swallowing
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What is the roof/superior wall of the middle ear called/made up of?
- Petrous portion of temporal bone
| - Called Tegmen Tympani (Thin membrane like bone)
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What is Thrombophlebitis and what part of the ear could it affect?
- When a superficial vein becomes inflamed and blood within it clots as a result
- Inferior wall of the middle ear due to Internal Jugular vein
- otitis media could erode through bone of inferior wall, causing clots to form
- Chronic inflammation of this region can also predispose
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What is the protrusion of bone into the medial wall of the middle ear?
Promentary (associated with Tympanic plexus of Tympanic nerve from CN IX)
