Head and Neck 4 Flashcards
1
Q
What is the larynx?
A
Tube lined by mucous membrane
Closed in front
Open in back
Skeleton is cartilage
2
Q
Which levels does the larynx run?
A
C3-C6
3
Q
C3
A
Hyoid level
4
Q
C6
A
Cricoid cartilage level
5
Q
What is the closed cartilage of the larynx called and what level is it found?
A
Cricoid cartilage
C6
6
Q
Name the cartilages of the larynx.
A
Thyroid (biggest, C4 to C5)
2 arytenoids (triangular shaped ontop of cricoid), corniculate ontop of arytenoid
Epiglottis
Cricoid
7
Q
What happens at C6 level?
A
Larynx changes into trachea
Pharynx changes into oesophagus
8
Q
What is the quadrate/quadrangular membrane?
A
Thin submucosal sheet of connective tissue
Extends from arytenoid cartilage to epiglottic cartilage
9
Q
Name the 2 folds of the quadrangular membrane.
A
Aryepiglottic fold (superior) Vestibular ligament covered by mucous membrane to form vestibular fold (inferior) = false vocal cords
10
Q
What does the aryepiglottic fold surround?
A
Inlet of larynx (aditus of larynx)
11
Q
What is the name of the vocal membrane?
A
Cricothyroid membrane
12
Q
Explain the location of the cricothyroid membrane.
A
Extends from the cricoid cartilage to thyroid/arytenoid cartilages
13
Q
What forms the vocal ligament?
A
Upper free edge that extends from the thyroid cartilage (close to midline) backwards to vocal process of arytenoid cartilage forms the vocal ligament
14
Q
What is the vocal fold/cord formed of?
A
Cricothyroid membrane covered by mucous membrane
15
Q
What is the skeleton of the vocal cord?
A
Cricothyroid membrane
16
Q
What is the rima glottidis?
A
Gap between the two vocal folds (vocal cord)
17
Q
Inlet/aditus
A
Space between aryepiglottic folds
18
Q
Vestibule
A
Space below inlet as far as vestibular folds
19
Q
Ventricle
A
Space between vestibular and vocal folds, indents laterally
20
Q
Saccule
A
Small pouch of mucous membrane between vestibular folds and laryngeal lamina
21
Q
Rima glottis
A
Space between vocal folds
22
Q
Piriform Recess
A
Space between quadrangular membrane and lamina of thyroid cartilage
23
Q
What is contained within the piriform fossa?
A
Internal laryngeal nerve
Superior laryngeal vessels
24
Q
Where does the cricothyroid muscle run?
A
From anterolateral part of cricoid cartilage to inferior aspect of thyroid cartilage
25
What is the innervation of the cricothyroid muscle and how does this differ from the other muscles?
Innervated by external laryngeal nerve
| All other muscles = recurrent laryngeal nerve
26
What is the action of the cricothyroid muscle?
Tenses and stretches vocal fold
27
Where is the thyroarytenoid muscle?
From posterior surface of thyroid cartilage
| Insertion into muscular process of arytenoid cartilage
28
What is the action of the thyroarytenoid muscle?
Relaxes vocal fold
29
Location and action of lateral crico-arytenoid muscles.
From arch of cricoid cartilage to muscular process of arytenoid cartilage
Adducts vocal fold
30
Where does the transverse arytenoid run and what is its function?
Runs between arytenoid - adducts arytenoids (pulls them together)
31
Where does the oblique arytenoid run and what is its function?
Runs superficial to transverse arytenoid
Runs from muscular process of one arytenoid to the apex of the other (cross over)
Aids in adduction - draw arytenoids closer together
32
Where is the aryepiglottic muscle found and what are its functions?
Oblique arytenoids are continuous as this larger sheet of muscle to the side of the epiglottis
Muscle acts as a sphincter (together with interarytenoids & epiglottis) = narrows laryngeal aditus and prevents swallowed material from entering (pulls aryepiglottic folds together)
33
What is the location of the posterior crico-arytenoid and its function?
From posterior surface of cricoid cartilage to muscular process of arytenoid cartilage
Action: abducts to bring in oxygen
34
What is the tensor muscle?
Cricothyroid
35
What is the relaxer muscle?
Thyro-arytenoid
36
Which are the adductor muscles?
Lateral crico-arytenoid
| Transverse and oblique arytenoids
37
What is the abductor muscle?
Posterior crico-arytenoid
38
What are the muscles innervated by?
All innervated by the recurrent laryngeal nerve, except the cricothyroid which is innervated by the external laryngeal nerve
39
What is the supply of the mucous lining of the larynx?
Above the vocal cord: internal laryngeal
| Below the vocal cord: recurrent laryngeal
40
What are the laryngeal nerves derived from?
Vagus nerve X
41
List the branches of the laryngeal nerve.
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Superior laryngeal - internal/external
Recurrent laryngeal (i.e. is actually the inferior laryngeal)
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42
What is the difference between the vagus nerve of the left and right sides?
Right side: very quickly gives off recurrent
| Left side: recurrent given off later
43
What membrane does the internal laryngeal nerve pierce?
Thyrohyoid membrane
44
What does the internal laryngeal nerve supply?
Sensory to laryngeal mucosa superior to vocal folds
45
What does the external laryngeal nerve descend with and what does it supply?
Descends with the superior thyroid artery
| Supplies the cricothyroid muscle
46
What is the difference in location of the right and left recurrent laryngeal nerve?
Right originates in root of neck
| Left originates in thorax
47
Where does the recurrent laryngeal nerve ascend?
In the groove between the trachea and the oesophagus
48
What surface is the recurrent laryngeal nerve related to?
Medial surface of the thyroid gland
49
What is the function of the recurrent laryngeal nerve?
Supplies all intrinsic muscles of the larynx, except for the cricothyroid muscle
Supplies sensory innervation for the laryngeal mucous membrane inferior to the level of the vocal cords/folds
50
What do the mylohyoid muscles form?
The floor of the mouth
51
Where do the mylohyoid muscles lie?
Origin: mylohyoid line of mandible
Insertion: raphe and body of hyoid
52
What is the function of the mylohyoid muscles?
Elevates hyoid bone, floor of mouth and tongue
| With the hyoid bone fixed, it depresses the mandible
53
What is the innervation of the mylohyoid muscles?
Mylohyoid nerve (branch of inferior alveolar nerve - V3)
54
Where are the geniohyoid muscles located?
Superior to the mylohyoid muscles
| From the inferior mental spine of the mandible to body of hyoid bone
55
What is the innervation of the geniohyoid muscles?
C1 via the hypoglossal nerve (XII)
56
What is the action of the geniohyoid bone?
Elevates hyoid bone, depresses mandible
57
List the layers of muscles from inferior to superior.
Platysma, digastric, mylohyoid, geniohyoid
58
Where does the lingual nerve arise from?
Mandibular nerve (V3)
59
Where does the lingual nerve run?
Runs inferiorly between the medial pterygoid and ramus of mandible
Anterior to inferior alveolar nerve
Runs on the hyoglossus muscle
60
What does the lingual nerve supply?
General sensation to mucosa of the anterior 2/3rds of the tongue and floor of the oral cavity
61
What runs on the hyoglossus muscle?
Highest: lingual nerve
Submandibular duct
Hyoglossal nerve
62
What is the chorda tympani a branch of?
Facial nerve (VII)
63
Where does it run?
Joins the lingual nerve and runs anteriorly to its sheath
64
What does the chorda tympani supply?
Special sensation to the anterior 2/3rds of the tongue
| Parasympathetic fibres to submandibular ganglion
65
What does the inferior alveolar nerve arise from?
Mandibular nerve V3 (trigeminal 5 nerve)
66
Where does the inferior alveolar nerve run?
Inferiorly between the medial pterygoid muscle and the ramus of the mandible
Enters the mandible through the mandibular foramen
Runs forward in the mandibular canal supplying sensory to the lower teeth
67
Where does the maxillary nerve come out from the skull?
Via the foramen rotundum
68
Where does the maxillary nerve travel?
Within the pterygopalatine fossa and gives off two branches which suspend the parasympathetic pterygopalatine region
Sensory fibres of the maxillary nerve pass through the ganglion without synapsing
Supply nose, palate, nasopharynx
69
Name the 5 branches coming out of the ganglion near the maxillary nerve.
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Greater and lesser palatine
Nasopalatine
Nasal nerves
Pharyngeal nerves
Alveolar nerves (posterior superior alveolar and anterior superior alveolar nerve)
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70
Where do the greater and lesser palatine nerves travel?
Pass inferiorly from the pterygopalatine ganglion, descend through the palatine canal and enter the palate through the greater and lesser palatine foramina
71
What is the function of the greater and lesser palatine nerves?
Greater: supply sensory to hard palate
Lesser: supply sensory to soft palate
72
Where does the nasopalatine nerve travel?
Runs medially and enters the nasal cavity
| Runs on nasal septum and through a foramen to anterior part of the hard palate
73
What do the nasal nerves supply?
Enter the nasal cavity to supply parts of the lateral wall and septum
74
What is the function of the pharyngeal nerves?
Pass posteriorly
| Supply the mucous membrane of the nasopharynx
75
Posterior superior alveolar nerve
Arise from maxillary nerve within the pterygopalatine fossa
| Descend to supply upper posterior teeth
76
Anterior superior alveolar nerve
Arises from infraorbital nerve and supplies the upper anterior teeth
77
Where does the glossopharyngeal nerve (IX) leave the skull?
Leaves the skull via the jugular foramen
Gives off pharyngeal branches to the pharyngeal plexus (sensory to mucosa of oropharynx)
Supplies one muscle = stylopharyngeus
Supplies general and special sensation (taste) to posterior third of tongue
78
List some nerves which latch onto other nerves.
- Chorda tympani (facial) on lingual nerve (mandibular) to submandibular, sublingual and anterior 2/3rds of tongue. Synapses in submandibular ganglion.
- Greater petrosal (facial) on zygomatic of V2, then on lacrimal nerve to lacrimal gland. Synapses in pterygopalatine ganglion. Stimulation of this causes tears.
- Lesser petrosal nerve (IX) on auriculotemporal nerve (V3) to parotid gland. Stimulation of lesser petrosal causes parotid secretion.
