Chapter 14: Embryology, Anatomy and Physiology of the Oral Cavity, Pharynx, Esophagus and Neck Flashcards
1
Q
Derive from embryonic foregut
A
- Oral cavity
- Pharynx
- Esophagus
- Nasal cavity
- Teeth
- Salivary glands
- Anterior pituitary
- Thyroid
- Larynx
- Trachea
- Bronchi
- Alveoli of the lungs
2
Q
Forms when the primitive stomodeum (fusion of the ectoderm and endoderm breaks down)
A
Mouth
3
Q
Formed by elements of the medial and lateral nasal processes and the maxillary processes
A
Upper lips
4
Q
Derived from the 2nd branchial region
Supplied by the facial nerve
A
Muscles of the lip
5
Q
Has a characteristic bowed appearance
A
Vermilion border of the lips
6
Q
Derived from the dental lamina, which give rise to the cementum and enamel of the definitive teeth
A
Teeth
7
Q
Supplied by the branches from the maxillary and mandibular branches of the trigeminal nerve
A
Teeth
8
Q
Palate is formed in 2 parts:
A
- Premaxilla: containing the incisor teeth and derived from the medial nasal process
- Posterior palate: both hard and soft palate, formed by fusion of the palatal shelves
9
Q
Lateral to the tongue and if the tongue does not descend, the palatal plates cannot fuse
This is the basis of the cleft palate associated with the micrognathia of the Pierre Robin syndrome
A
Palatal plates
10
Q
Formed from several epithelial eminences in the floor of the mouth
A
Tongue
11
Q
Derived mainly from the 1st branchial region
Supplied by the lingual nerve, with the chorda tympani branch of the facial nerve supplying the taste buds and the secretomotor supply of the submandibular gland
A
Anterior tongue
12
Q
Supplies all the sensation to the posterior 3rd of the tongue
A
Glossopharyngeal nerve
13
Q
Derived from postbranchial myotomes that migrate forward, bringing with them the hypoglossal nerve
A
Muscles of the tongue
14
Q
Arises from the foramen cecum in the posterior part of the tongue
Migrates along the thyroglossal duct into the neck
Migration does not occur: lingual thyroid
A
Thyroid
15
Q
May persist and may be tucked up behind the body of the hyoid bone
A
Remnants of the thyroglossal duct
16
Q
Anterior to the free margin of the soft palate, anterior tonsillar pillar and base of the tongue
A
Oral cavity
17
Q
Divisions of pharynx
A
- Nasopharynx: extends from the base of the skull to the level of the soft palate
- Oropharynx: extends from this level to the level of the epiglottis
- Laryngopharynx/hypopharynx
18
Q
Composed mainly of the bulk of the orbicularis oris muscle
Supplies by the facial nerve
A
Lips and cheeks
19
Q
Is red due to a thin squamous epithelial covering
A
Vermilion
20
Q
Region between the internal mucosa of the cheek and the teeth
A
Vestibule of the mouth
21
Q
Opens opposite the upper 2nd molar
A
Parotid duct
22
Q
Teeth are supported by:
A
- Superior: maxillary alveolar ridge
2. Inferior: mandibular alveolar ridge
23
Q
Infant dentition consists of
A
2 incisors
1 canine tooth
2 molar teeth
24
Q
Adult dentition consists of
A
2 incisors
1 canine
2 premolar
3 molar
25
Area between the upper and lower posterior molars
Retromolar trigone
26
Palate is made up of:
Anterior: bone of the hard palate
Posterior: highly muscular soft palate
27
Can be raised to seal the nasal pharynx from the oral cavity and oropharynx
Inability to make such seal-->abnormal speech (rhinolalia aperta) and difficulty in swallowing
Soft palate
28
Opens anteriorly on either side of the lingual frenulum
| Failure of the salivary glands to secrete saliva causes a dry mouth or xerostomia
Submandibular ducts
29
Mobile muscular organ
Anterior 2/3: mobile
Posterior: fixed
Tongue
30
Muscles of the tongue are supplied by
Hypoglossal nerve
31
Innervation of the anterior 2/3 of the tongue (common sensation)
Lingual nerve
32
Innervation of the posterior 1/3 of the tongue
Glossopharyngeal nerve
33
Supplies taste to the anterior 2/3 of the tongue
Chorda tympani
34
Site of origin of the thyroglossal duct
Foramen cecum at the apex of the V
35
Provides general sensation to the tongue
Lingual nerve
36
Transverses the mandible and exits through the mental foramen
Provides sensation to the lower lip region
Mental nerve
37
Behind the mucosa of the posterior wall of the pharynx
Superior
1. Basisphenoid
2. Basiocciput
3. Anterior portion of the atlas
4. Bodies of the axis
5. Other cervical vertebrae
38
Nasopharynx opens...
Anterior: into the nose via the posterior choanae
Superior: adenoids lies on the mucosa of the roof of the nasopharynx
Lateral: opening of the cartilaginous ET occupies a region anterior to a recess (fossa of Rosenmüller)
39
Enters the pharynx via the fossa of Rosenmüller
Tensor palatini
40
Functions of tensor palatini
1. Tenses the palate
| 2. Opens the ET
41
Innervation of tensor palatini
Mandibular nerve via the otic ganglion
42
Communicates anteriorly with the oral cavity
Oropharynx
43
Anterior tonsillar pillar is composed of..
Palatoglossus muscle
44
Posterior tonsillar pillar is composed of...
Palatopharyngeus
45
Muscles of tonsillar pillar is innervated by...
Pharyngeal plexus of nerves
46
Muscles help close the posterior oropharynx
Muscles of tonsillar pillar
47
Composed of lymphoid tissue covered by squamous epithelium containing many crypts
Tonsil
48
Represents the remnant of the endodermal opening of the 2nd branchial arch (this is where a 2nd branchial fistula or internal sinus will open)
Cleft above the tonsil
49
Infection may collect between the capsule of the tonsil and the loose surrounding tissues and may track up toward the base of the soft palate
Peritonsillar abscess
50
Opens anteriorly into the introitus of the larynx
Hypopharynx
51
Attached to the base of the tongue by 2 lateral and 1 midline frenulum (these produce 2 valleculae on either side)
Epiglottis
52
Develops through the posterior pharyngeal wall below the inferior constrictor and above the cricopharyngeus
Zenker's diverticulum
53
An area in which the air passages from the nose to the larynx cross the food passages from the mouth to the esophagus
Pharynx
54
Dysfunction of pharyngeal musculature
1. Difficulty in swallowing
| 2. Aspiration of saliva or food into the tracheobronchial tree
55
In the early embryo...
No well-defined neck separating the thorax from the head
56
Is formed as the heart, which originally below the foregut, migrates into the thorax and the branchial apparatus develops its final form
Neck
57
Is the reason why many of the structures of the neck migrate caudally
Migration of the heart
58
Never develops in man
| Only derivative is the ligamentum arteriosum
5th arch
59
Ever visible externally
Only 4 arches
60
Each of the branchial arches contains...
1. Cartilaginous bar
2. Artery
3. Nerve
4. Some mesenchyma that will form muscle
61
Each of the branchial arches contains...
1. Cartilaginous bar
2. Artery
3. Nerve
4. Some mesenchyma that will form muscle
62
Area between the ectoderm and endoderm
Closing plate
63
Located posterior to the cartilaginous arch, artery and nerve
Ectodermal cleft and endodermal pouch
64
Abnormal persistence of parts of the branchial apparatus can lead to...
1. Cyst
2. Sinus
3. Fistula
65
May result in a cyst or sinus lying parallel to and even reduplicating the external ear canal
Persistence of the ectoderm of the 1st branchial arch
66
Requires identification and dissection of the facial nerve
Excision of a 1st branchial cleft cyst
67
Abnormal in the Treacher Collins syndrome
Bony derivatives of the 1st arch
68
May form a persistent stapedial artery that passes through the crura of the stapes (presence of such artery, impossible to perform a stapedectomy)
Artery of the 2nd arch
69
External openings of the 2nd, 3rd and 4th arches are covered over by growth of an area
Epipericardial ridge
70
Epicardial ridge fuses with the 2nd branchial arch, burying the opening of the 2nd, 3rd and 4th branchial grooves as an ectodermal cyst, which degenerates
Cervical sinus of His
71
The tract of a branchial cleft cyst must...
Pass superior to the hypoglossal nerve
72
Will open anterior to the SCM, pass into the neck anterior to the common and ICA, between the ICA and ECA, and then above the glossopharyngeal and hypoglossal nerves to reach the tonsil
Second branchial fistula
73
Will open anterior to the SCM, pass posterior to the common and ICA and above the hypoglossal nerve but below the glossopharyngeal nerve and stylopharyngeus, to enter the pharynx above the region supplied by the superior laryngeal nerve
3rd branchial fistula
74
May persist as a tract from the inferior pharynx to the region of the thyroid and may occasionally be a cause of suppurative thyroiditis
Remnant of the 4th branchial pouch
75
Pharyngeal blood supply derives from various branches of the...
External carotid system
76
Pharyngeal blood supply (anastomoses)
1. Terminal branches of the internal maxillary artery
2. Tonsillar branch of the facial artery
3. Dorsal lingual branch of the lingual artery
4. Branch of the superior thyroid artery
5. Ascending pharyngeal artery
77
Sensory supply to the nasopharynx and oropharynx and base of the tongue
Pharyngeal plexus of the glossopharyngeal nerve
78
Pharyngeal lymphatic drainage
Retropharyngeal and lateral pharyngeal chains with subsequent passage into the deep cervical nodes
79
Nasopharyngeal malignancies often metastasize into the...
Posterior cervical chain
80
Functions of pharynx
1. Respiration
2. Deglutition
3. Voice resonance
4. Articulation
81
3 stages of deglutition
First: voluntary movement of food from the mouth into the pharynx
Second: transport of food through the pharynx (involuntary)
Third: passage of the bolus through the esophagus (involuntary)
82
Deglutition
Mastication of food is positioned on the middle 3rd of the tongue--->elevation of both the tongue and soft palate forces the bolus into the oropharynx--->suprahyoid muscles contract, elevating the hyoid bone and larynx--->opening the hypopharynx and the piriform sinuses--->intrinsic laryngeal muscles contract in a sphincter-like fashion to prevent aspiration--->a strong motion of the tongue posteriorly plunges the food inferiorly through the oropharynx, a movement aided by the contraction of the superior and middle pharyngeal constrictors--->bolus is guided through the esophageal introitus when the inferior pharyngeal constrictor contracts and cricopharyngeus muscle relaxes--->peristalsis, assisted by gravity, moves the food down the esophagus and into the stomach
83
Areas of loose connective tissue that may be the sites of abscess formation as well as pathways by which infection may spread
Fascial spaces of the head and neck
84
Layers of thickened connective tissue enclosing the muscles and organs
Fascial sheath
85
Functions of fascial sheath
1. Protection
| 2. Allow the movement of the structures against one another
86
Encircles the scalp, face and neck subcutaneously to enclose the muscles of facial expression and the platysma
Superficial cervical fascia
87
Components of deep cervical fascia
1. Superficial component: investing layer
2. Middle component: pretracheal (visceral) layer
3. Deep component: vertebral (prevertebral) layer
88
Encircles the neck, attaching only to the nuchal ligament of the vertebrae posteriorly
Splits to enclose the trapezius and SCM but lies anteriorly to the strap muscles
Investing layer
89
Limited to the anterior neck below the hyoid bone
Attaches to the superficial layer at the lateral border of the strap muscles on each sides, extends posterior to these muscles in front of the larynx and trachea
Encircles the thyroid gland
Pretracheal layer
90
Attaches to the nuchal ligament and encircles the neck
Covers the vertebral bodies and the scalene muscles anteriorly and the paraspinous and deep neck muscles laterally
Splits to form 2 layers, an alar part anteriorly and a true prevertebral part posteriorly
Vertebral layer
91
Space between alar part and true prevertebral part
| Infection may spread downward to the chest
Danger space
92
Between the prevertebral layer and the pretracheal layer on each side is a tube of fascia encircling the carotid artery, vagus nerve and jugular vein
Carotid sheath
93
Becomes external to the suprahyoid musculature but then splits to enclose the mandible and muscles of mastication
Forms the capsules of the submandibular and parotid glands
Investing layer
94
Extends above the hyoid bone posteriorly only as a layer encircling the pharyngeal muscles
Pretracheal layer
95
Unchanged above the level of the hyoid
Vertebral layer
