Clinical anatomy of the layrnx Flashcards
1
Q
what is the airway divided into
A
- upper airway and the lower airway
2
Q
what separates the upper and lower airways
A
- the larynx
3
Q
how many cartilages make up the larynx
A
9
- 3 paired
- 3 unpaired
4
Q
where is the larynx in terms of spinal segments
A
- Resits at C3-C6
5
Q
what does the larynx continue with above and below
A
Connected to the
- Hyoid bone superiorly
- Trachea inferiorly
it is continuous with the pharynx superiorly as well
6
Q
what are the main cartilages of the larynx
A
paired
- arytenoid
- corniculate
- cuneiform
unpaired
- thyroid
- epiglottis
- cricoid
7
Q
describe the structure of the epiglottis
A
- Its tip rises about 1cm above the body of the hyoid at the back of the tongue
- Its ‘stalk ’ is attached to the back of the anterior aspect of the thyroid cartilage.
8
Q
what is the largest cartilage of the larynx
A
thyroid cartilage
9
Q
describe the attachments fo the thyroid cartilage
A
- lies just beneath the hyoid bone
- Composed of two sheets (laminae), which fuse anteriorly to form thelaryngeal prominence(Adam’s apple).
- The posterior border of each sheet projectsuperiorly and inferiorly to form the superior and inferior horns (also known as cornu).
- The superior hornsare connected to the hyoid bone via the lateral thyrohyoid ligament, while the inferior horns articulate with the cricoid cartilage.
10
Q
where does the cricoid cartilage sit
A
- It articulates with the inferior horns of the thyroid cartilage superiorly
- Posteriorly it is connected to the two arytenoid cartilages by synovial joints
- Inferiorly it is attached to the trachea
11
Q
what is special about the cricoid cartilage
A
It is the only completely ring of cartilage in the larynx, the front of it is quite narrow whereas the back part of it is quite tall
12
Q
where do the arytenoids sit
A
- they sit on top of the cricoid cartilage
13
Q
what is the lower respiratory tract made up of
A
Lower airway – essentially everything beyond the trachea
14
Q
what are the three parts of the pharynx
A
naso, oro, laryngo-
15
Q
what is the role of the nasal cavity
A
- Warms and humidifies inspired air
- Removes and traps pathogens from inspired air
- Sense of smell
- Drains paranasal sinuses and lacrimal ducts
16
Q
where does the nasal cavity extend from
A
It extends from the vestibule of the nose to the nasopharynx, and has three divisions
17
Q
what are the parts of the nasal cavity
A
- Vestibule– the area surrounding the anterior external opening (nostrils) to the nasal cavity.
- Respiratory region– lined by a ciliated psudeostratifiedepithelium, interspersed with mucus-secreting goblet cells. Responsible for trapping pathogens and particulates within inspired air.
- Olfactory region– located at the apex of the nasal cavity. It is lined by olfactory cells with olfactory receptors. Special sensory innervation refers to the ability of the nose to smell. This is carried out by the olfactory nerves. The olfactory bulb, part of the brain, lies on the superior surface of the cribriform plate, above the nasal cavity. Branches of the olfactory nerve run through the cribriform plate to provide special sensory innervation to the nose.
18
Q
where does the oral cavity extend
A
Spans between oral fissure anteriorly and the opening of the oropharynx posteriorly.
19
Q
what are the two divisions of the oral cavity
A
Two major divisions of the oral cavity:
Vestibule
Oral Cavity Proper
20
Q
what is the sensory innervation of the oral cavity
A
Sensory innervation of the oral cavity is supplied by branches of the trigeminal nerve (CN V)
21
Q
what is the function of the oral cavity
A
Function of the oral cavity:
Digestion
Communication
Breathing
22
Q
what is the vestibule
A
Vestibule - horseshoe-shaped vestibule is situated anteriorly. It is the space between the lips/cheeks, and the gums/teeth
23
Q
where does the oral cavity proper sit
A
- Lies posteriorly to the vestibule.
- It is bordered by a roof, a floor, and the cheeks.
- The tongue fills a large proportion of the cavity of the mouth proper.
24
Q
what does the roof of the oral cavity consist of
A
Roof consists of anterior hard palate and posterior soft palate.
25
describe the hard plate and what is separates and what mucosa lines it
- The hard plate separates the nasal cavity from the oral cavity.
- It is covered superiorly by respiratory mucosa (ciliated pseudostratified columnar epithelium) and inferiorly by oral mucosa (stratified squamous epithelium).
- has a contribution from the palatine bone
26
describe the soft palate
The soft palate is a muscular (not bony) continuation of the hard palate posteriorly
27
what are the cheeks formed by
Cheeks formed by the buccinator muscle, which is lined internally by the oral mucous membrane.
28
what is the bony skeleton of the oral cavity made up of
The bony skeleton of the oral cavity is made up of the maxilla and mandible which house the upper and lower teeth respectively
29
what makes up walders ring
- uvula
- paltoglossal arch
- palto pharygneal arch
- paltine tonsils
30
what is the pharynx
Muscular tube connecting oral and nasal cavities to the trachea and oesophagus
31
what is the shape of the pharynx controlled by
Shape of pharynx and propulsion of food into oesophagus controlled by two sets of pharyngeal muscles – circular and longitudinal muscles
32
what are the two sets of pharyngeal muscles
circular and longitudinal
33
where is the nasopharynx found
Nasopharynx - found between the base of the skull and the soft palate.
34
what is the role of the nasopharynx
It is continuous with the nasal cavity, and performs a respiratory function by conditioning inspired air and propagating it into the larynx.
35
what epithelium of nasopharynx lined with
Lined with respiratory epithelium; ciliated pseudostratified columnar epithelium with goblet cells
36
where is the oropharynx located
Oropharynx – The middle part of the pharynx, located between the soft palate and the superior border of the epiglottis.
37
what structures does the oropharynx contain
It contains the following structures:
- Posterior 1/3 of the tongue.
- Lingual tonsils – lymphoid tissue at the base of the tongue.
- Palatine tonsils – lymphoid tissue located in the tonsillar fossa (between the palatoglossal and palatopharyngeal arches of the oral cavity).
- Superior constrictor muscle
Waldeyer’s ring is the ring of lymphoid tissue in the naso- and oropharynx formed by the paired palatine tonsils, the adenoid tonsils and lingual tonsil.
38
what is the role of the oropharynx
The oropharynx is involved in the voluntary and involuntary phases of swallowing.
39
where is the laryngopharyx located
The most distal part of the pharynx, the laryngopharynx is located between the superior border of the epiglottis and inferior border of the cricoid cartilage (C6). It is continuous inferiorly with the oesophagus.
40
what does the laryngopharyx contain
The laryngopharynx contains the middle and inferior pharyngeal constrictors.
41
what does the layryx contain
Composed of 9 cartilages with connecting ligaments, muscles and vocal cords and lined by mucous membrane
42
what happens to the larynx after puberty in men
After puberty the male larynx enlarges with the saggital diameter nearly doubling and all the cartilages increase in both size and weight,
43
what skeletal level does the hyoid sit at
C3
44
what supports the larynx cartilages
The laryngeal membranes and ligaments support this cartilaginous skeleton of the larynx.
45
what does the intrinsic muscles of the larynx do
The intrinsic laryngeal muscles act to move the components of the larynx for phonation and breathing.
46
what are the corniculate, cuneiform, tritiate and epiglottic cartilages and the apices of the arytenoid composed of
The corniculate, cuneiform, tritiate and epiglottic cartilages and the apices of the arytenoid are composed of elastic fibrocartilage, with little tendency to calcify
47
what cartilages are composed of hyaline cartilage
- The thyroid, cricoid and the greater part of the arytenoid cartilages consist of hyaline cartilage and may undergo mottled calcification as age advances,
- starting about the twenty-fifth year in the thyroid cartilage and somewhat later in the cricoid and arytenoids.
- By the sixty-fifth year, these cartilages commonly appear patchily dense in radiographs
48
what is the epiglottis composed of
It is composed of yellow cartilage and never calcifies.
49
what does the epiglottis do when swallowing
During swallowing, the epiglottis flattens and moves posteriorly to close off the laryngeal inlet and prevent aspiration.
50
how does the laryngeal prominence form
- Composed of two sheets (laminae), which fuse anteriorly to form the laryngeal prominence (Adam’s apple).
- This prominence has a palpable v shaped notch is more easily visible in adult males with the sheets fusing at a 90 degree angle compared to around 120 degrees in females.
51
what is the angle difference between the laryngeal prominence for males and females
- This prominence has a palpable v shaped notch is more easily visible in adult males with the sheets fusing at a 90 degree angle compared to around 120 degrees in females.
52
where are the vocal cords in relative to the thyroid cartilage
The true vocal folds lie 6–9 mm below the median thyroid notch;
53
how is the thyroid cartilage attached to the cricoid cartilage
the thyroid cartilage is connected to the cricoid cartilage by the median (anterior) cricothyroid ligament, which is the thickened medial portion of the conus elasticus.
54
what is the synovial joint in the larynx
On the anteromedial surface of the inferior cornu its lower end there is a small oval facet for articulation with the side of the cricoid cartilage; this is a synovial joint.
55
describe how the cricoid cartilage changes anteriorly and posteriorly
narrower arch anteriorly 5mm
| consisting of a broad sheet posteriorly 25mm
56
how is the cricoid attached to other cartilages
- Cricothyroid is attached to the external aspect of its front and sides, and cricopharyngeus (part of the inferior pharyngeal constrictor) is attached behind cricothyroid.
- Posterior cricoarytenoid attaches to a shallow depression on either side of a posterior ridge
- The inferior border of the cricoid is horizontal, and joined to the first tracheal cartilage by the cricotracheal ligament.
- The superior border runs obliquely up and back, and gives attachment anteriorly to the thick median cricothyroid ligament, and laterally to the conus elasticus and lateral cricoarytenoid.
- The posterosuperior aspect of the lamina presents a shallow median notch, on each side of which is a smooth, oval, convex facet, directed upwards and laterally, for articulation with the base of an arytenoid cartilage.
57
what is the largest paired cartilage
arytenoids are largest
| - hyaline cartilage
58
describe the structure of the arytenoid and what the anterior point is called and what it does
- resembles a three sided pyramid pointing superiorly and sitting on the posterior aspect of the cricoid.
59
what is the anterior point called on the arytenoids cartilage
- Their anterior point is called the vocal process and connects to the vocal ligament
60
where are the corniculate cartilages and what are they made out of
The corniculate cartilages (elastic) sit atop the arytenoids
61
where are the cuneiform cartilages and what are they made out of
The cuneiform cartilages (elastic) are above the corniculates located within the ary-epiglottic folds
62
what view point is best for the corniculate and uniform cartilages
laryngoscopic view
63
what does the thyroihyoid membrane do
Thyrohyoid membrane – Spans between the superior aspect of the thyroid cartilage and the hyoid bone.
.
64
what goes through the thyrohyoid membrane
It is pierced laterally by the superior laryngeal vessels and internal laryngeal nerve (branch of the superior laryngeal nerve)
65
describe the structure of the thyrohyoid membrane
- In the midline it is thickened and is called the median thyroihyoid ligament at this point.
- At the posterior edges are the lateral thyrohyoid ligaments which extend from the superior horn of the thyroid cartilage to the tip of the greater horn of the hyoid bone.
66
what are the median and lateral thyrohyoid ligaments
Median thyrohyoid ligament – Anteromedial thickening of the membrane.
Lateral thyrohyoid ligaments – Posterolateral thickenings of the membrane
67
what does the hypo epiglottic ligament do
Hyo-epiglottic ligament – Connects the hyoid bone to the anterior aspect of the epiglottis.
68
what does the cricotracheal ligament do
Cricotracheal ligament – Connects the cricoid cartilage to the trachea.
69
list the extrinsic ligaments
```
Thyrohyoid membrane
Median thyrohyoid ligament
Lateral thyrohyoid ligament
Hyo-epiglottic ligament
Cricotracheal ligament
```
70
list the intrinsic ligaments
Cricothyroid ligament
| Quadrangular membrane
71
describe how the Cricothyroid ligament attaches
- Cricothyroid ligament – Originates from the cricoid cartilage and extends superiorly, where it terminates with an free (unattached) upper margin – which forms the vocal ligament.
- Together with the overlying epithelium they form the vocal folds. I
- attached anteriorly to the thyroid cartilage,
- posteriorly to the vocal process of the arytenoid cartilage.
- It is a highly elastic membrane
72
which ligament helps form the vocal ligament
cricothryoid
73
how are the vocal folds and ligaments formed
- Cricothyroid ligament – Originates from the cricoid cartilage and extends superiorly, where it terminates with an free (unattached) upper margin – which forms the vocal ligament.
- Together with the overlying epithelium they form the vocal folds.
74
how does the Cricothyroid ligament form the median Cricothyroid ligament
thickened anteriorly to form the median cricothyroid ligament.
75
where does the quadrangular membrane span
– Spans between the anterolateral arytenoid cartilage and the lateral aspect of the epiglottis.
- it has a free upper margin and a lower margin
76
what does the free upper margin and the lower margin of the quadrangular membrane form
- It has a free upper margin and lower margin.
- The free upper margin forms the aryepiglottic fold.
- The lower margin is thickened to become the vestibular ligament or fold known as the false cord.
77
what three regions is the larynx divided up into
1. the vestibule (from laryngeal opening to vestibular folds)
2. the ventricle (between the vestibular and vocal folds)
3. the infraglottic area (below the vocal folds, continuous with the trachea
78
what is the primary source of phonation
The vocal ligament which is the upper free edge of the cricothyroid membrane. They give shape to the true vocal folds lying beneath the vestibular fold.
- the vestibular folds do not usually contribute
79
what epithelium is on the vocal folds and the vestibular folds where the contact each other and why
The vocal and vestibular folds are covered by non-keratinized, stratified squamous epithelium where they contact each other;
- this important variation protects the tissue from the effects of the considerable mechanical stresses that act on the surfaces of the vocal folds.
80
what is the rest of the interior larynx covered by
ciliated, pseudostratified respiratory epithelium providing a mucociliary clearance mechanism
81
what do the vocal ligaments and folds divide the larynx into
- They divide the larynx into 3 different places
- The laryngeal vestibule is the region between the laryngeal inlet and vestibular folds.
- The laryngeal ventricle (also known as the laryngeal sinus) is a slit between the vestibular folds above and the true vocal folds below.
82
describe the structure of the vocal folds
They are relatively avascular, and appear white in colour..
83
what is the space between the vocal cords known as
the rima glottidis.
84
what gives the vestibular fold its shape
The vestibular fold is given shape by the quadrangular membrane
85
describe the vestibular fold structure
- The inferior border of the membrane forms the vestibular ligament
- The superior free edge of the ligament can be seen as the aryepiglottic fold.
- The median aperture between them is the rima vestibuli
86
what is the function of the larynx
- Protection of the airway
- Effort closure in coughing, sneezing and abdominal straining
- Phonation
87
what is the definition of stridor
high pitched breath sound due to turbulent air flow through the larynx or lower bronchial tree. It is a symptom of an obstructed airway.
88
describe the mechanism by which the epiglottis prevents the food from going down the trachea
- hyoid bone is elevated
- this pulls the larynx upwards
- aryepiglotticus muscles in the aryepiglottic fold contract this results in the epiglottis flattening and becomes more horizontal
- it eventually comes into contract with the arytenoid cartilages
- this closes the laryngeal inlet
89
what is the phases of cough (effort closure)
1) Inspiratory – generates intrathoracic volume
2) Compression – concomitant closure of the vocal cords with contraction of muscles of the chest and abdominal wall causes a rapid rise in intrathoracic and intra-abdominal pressure
3) Expiratory phase – the glottis opens with explosive airflow
90
what is the function of effort closure in
- coughing
- sneezing
- heaving lifting
- vomitting
- defecating
Coughing: dislodges mucus, fluids, irritants from the airway
Sneezing: expels mucus from the nasal cavity
Heavy lifting: stabilise the trunk
Vomiting: intra-abdominal pressure and relaxation of oesophageal sphincters allows expulsion of vomitus
Defecating: intraabdominal pressure and relaxation of anal sphincters allows expulsion of faeces
91
what is a cough
A cough is a sudden, and often repetitively occurring, protective reflex which helps to clear the large breathing passages from fluids, irritants, foreign particles and microbes.
92
what are the three phases of the cough reflex
inspiratory
compression
expiratory
93
what happens when you sneeze
- soft palate and palatine uvula depress
- back of the tongue elevates to partially close the passage to the mouth so that air ejected from the lungs may be expelled through the nose
- some air is expelled through the mouth as the closing of the mouth is partial
94
what is frequency determined by
tension in the laryngeal muscles
95
what do the intrsic muscles control
- the shape of the rima glottidis by acting on the arytenoid cartilage to adduct or abduct the vocal cords
- the length and tension of the vocal folds to alter pitch
96
what makes up the intrinsic muscles of the larynx
- oblique arytenoid muscle
- transverse arytenoid muscled
- thyroartyenoid muscle
- posteriorly cricoarytneoid muscled
- lateral Cricoarytenoid muscle
97
what muscles conduct adduction of the vocal cords
lateral Cricoarytenoid
- adducts and medially rotates
transverse arytenoids
- slides the arytenoids laterally
(oblique arytenoids Oslo share this function)
98
what kind of joint is the cricoarytneoid joints
synovial
99
what muscles conduct abduction of the vocal cords
Posterior cricoarytenoid:
- Abducts and laterally rotates arytenoids
- The only muscle to abduct the cords
100
where do the lateral cricoarynteoid muscles arise from and pass back to
The lateral cricoarytenoid muscles arise from cricoid arch and passed backwards to the muscular processes of the arytenoid cartilages
101
describe the
- attachments
- action
- innervation of the lateral Cricoarytenoid
Attachments: Originates from the arch of the cricoid cartilage, and attaches to the muscular process of the arytenoid cartilage.
Actions: Adducts the vocal folds.
Innervation: Inferior laryngeal nerve (branch of recurrent laryngeal).
102
describe the
- attachments
- action
- innervation of the transverse and oblique arytenoids
Attachments: Spans from one arytenoid cartilage to the opposite arytenoid.
Actions: Adducts the arytenoid cartilages.
Innervation: Inferior laryngeal nerve (branch of recurrent laryngeal).
103
what muscles are involved in changing the pitch
- Cricothyroid muscle
| - thryoarytneoid muscle and vocalis
104
what muscles raises the pitch
Cricothyroid muscle:
Tilts the thyroid cartilage forwards
Tenses the vocal cords
Raises the pitch
105
what muscles lower the pitch
Thyroarytenoid muscle and vocalis:
Pulls the thyroid and arytenoid cartilages together
Relaxes the vocal cords
Lowers the pitch
(Vocalis alters the mass and timbre of the cords)
106
where does the Cricothyroid muscle arise and attach
Each arises from the anterolateral region of the cricoid cartilage and attaches onto the lower border of the thyroid cartilage.
107
what are the
- attachments
- actions
- innervation of the thyroarytenoid muscles
Attachments: Originates from the inferoposterior aspect of the angle of the thyroid cartilage, and attaches to the anterolateral part of the arytenoid cartilage.
Actions: Relaxes the vocal ligament.
Innervation: Inferior laryngeal nerve (branch of recurrent laryngeal).
108
what does the superior laryngeal split into
internal and external laryngeal nerve
109
what dose the internal laryngeal innervate
- sensory innervation to area above vocal cords
110
what does the external laryngeal innervate
- motor to Cricothyroid muscle
| - pitch
111
what does the recurrent laryngeal nerve innervate
- motor to all intrsic muscles except Cricothyroid
- sensory innervation to an area below vocal cords
- phonation
112
what does a lesion on the recurrent laryngeal lead to
- vocal cord paralysis (inability to abduct laterally)
| - hoarseness, aphonia, stridor
113
what does a lesion on the external laryngeal nerve lead to
- cricothyroid paralysis preventing higher pitched phonation
- weak voice, low pitch, easily tires, reduced range
114
what can cause recurrent laryngeal nerve damage and superior laryngeal nerve damage
- Surgery to the neck, particularly thyroid
- Tumours (often thyroid) compressing nerve
- Trauma
- Viral infection
115
what is the vascular supply to the superior laryngeal
- superior thyroid artery which extends from the external carotid artery
- superior thyroid vein drains above the glottis into the internal jugular
116
what is the vascular supply to the inferior laryngeal
- inferior thyroid artery which extends from the thyrocervical trunk
- inferior thyroid vein drains below the glottis into the brachiocephalic vein
117
what is the lymphatic drainage
Superior to the glottis: via superior deep cervical lymph nodes
Inferior to the glottis: via inferior deep cervical lymph nodes
118
what is a laryngocoele
- this is a herniation of the saccular mucosa
- due to high transglottal pressures repeatedly
- expands upwards into the paraglottic space and extend into the thyroid membrane
- can be palpable in the neck
- hoarseness stridor and dysphagia are symptoms
119
what is a normal emergency airway
endotracheal incubation
120
what is cricoid pressure
cricoid pressure refers to digital pressure against the cricoid cartilage of the larynx, pushing it backwards with the intention of oesophageal compression against the vertebrae and prevention of passive regurgitation of gastric and oesophageal contents
121
what is an emergency airway called
tracheotomy
