Part 2 Flashcards
1
Q
At week 6 the rupture of the oronasal membrane connects what two cavities
A
1) Nasal and oral cavity
2
Q
Congenital anomalies
A
1) Agenesis of Thyroid Gland
2) Thyroid Hemiagenesis
3) DiGeorge Syndrome
3
Q
What forms the mesenchyme
A
NCC migrating from forebrain, midbrain and hindbrain
4
Q
Describe the innervation of the inner ear
A
CN VIII
5
Q
External Ear Structure
A
Elastic Cartilag e
6
Q
4th and 6th Pharyngeal Cartilages form what?
A
Laryngeal Cartilages
- 4th also forms epiglottis (NCC derived)
7
Q
PA 3 Cartilage
A
1) Ossifies –> Greater Cornu of Hyoid Bone
2) Body of hyoid bone formed via hypopharyngeal eminence that formed via PA3 and PA4
8
Q
Riechert’s Cartilage forms what?
A
1) Dorsal –> Stapes and Styloid Process of temporal bone
2) Perichondrium –> Stylohyoid ligament
3) Ventral end ossifies –> Lesser cornu/horn of hyoid bone
9
Q
What is the structure that sensory hair cells are attached to in the Ampulla?
A
Cupulla
10
Q
Mastoiditis
A
1) Infection of Mastoid cells
- Can spread into cranial fossa via petrosquamous cranial suture
- Treated w. antibiotics
11
Q
What sensory structure do utricle and saccules contain
A
Maculae
12
Q
First Arch Syndrome
A
Malformation of eyes, ears, mandible, and palate
13
Q
Describe what happens when the basilar membrane vibrates
A
1) Basilar Membrane vibrates via sound
2) Movement of sterocilia –> K+ channels to open
3) Signal transferred to Bipolar neuron in spiral ganglion –> CN 8
14
Q
Pharyngotympanic tube
A
1) connects tympanic cavity to nasopharynx
2) Equalizes pressure via opening
15
Q
Once the Oropharyngeal membrane disintegrates, what mandibular prominences extend and fuse into what?
A
Lower Jaw and Surface of Upper Lip
16
Q
What ossicle amplifies the vibratory force
A
Stapes
17
Q
Structural Features of the Auricle
A
1) Concha of Auricle
2) Helix -(outer rim) and antihelix (inner rim)
3) Tragus (Protrusion overlapping external acoustic meatus) and antitragus
4) Lobule (contains non-cartilagenous)
18
Q
4th Pouch
A
1) Dorsal Portion –> Superior Parathyroid glands
2) Ultimobranchial body –> Fuses w/ thyroid gland and gives rise to parafollicular to parafollicular cells
19
Q
Structural Features of the Auditory Ossicles
A
1) Malleus, Incus and Stapes
- Tympanic membrane –> Malleus –> Incus –> Stapes –> Oval Window
20
Q
How does de-amp occur
A
Tensor Tympani
21
Q
Describe Pharyngeal Grooves
A
Located externally between pharyngeal arches, covered w/ ectoderm
22
Q
PA2 gives rise to what generally?
A
1) Stapedius and Muscles of Facial Expression
23
Q
What separates the LNP to the Maxillary Prominences
A
Nasolacrimal Groove
24
Q
Action of Tensor Tympani
A
Pulls on handle to tense membrane and reduce amplitude
25
What defective protein is involved with TCS?
TREACLE
26
Tympanic Membrane
1) Inner surface = auriculotemporal n. V3
| 2) Outer Surface = small auricular branch of CN X
27
Basic Function of the Inner Ear
1) Changes sound mechanical energy into electrical energy
| 2) Balance via rotational and linear acceleration
28
Cupulla is displaced via fluid motion and this allows detection of what kind of velocity
Rotational
29
Describe the completed palate formation
1) Bone fomation extends from the premaxillary part of the maxilla to the maxillae and palatine bone
2) Gives rise to:
- Hard Palate (Formed from lateral palatine bones)
- Soft Palate (Posterior portions don't ossify)
- Nasopalatine Canal persists in median plane and known as incisive fossa
30
What does the EAM contain?
1) Ceruminous glands (earwax)
| 2) Sebaceous gland
31
Tympanic Membrane Structure
1) Between the external and middle ear and has flaccid and tense portion
- Outer portion = stratified squamous
- Inner Portion - simple cuboidal
32
Basic Function of the Middle Ear
Amp. or De-amp of sound and equalization
33
What antibiotic must you avoid when treating a rupture ear drum?
Gentamicin
34
Thyroid Hemiagenesis (Unilateral failure of formation)
1) Left lobe is more commonly absent
| - Mutations in the receptor for thyroid-stimulating hormone are likely involved
35
3rd Pouch
1) Dorsal portion differentiates into inferior parathyroid gland
2) Ventral portions for the thymus
36
Describe Cleft Lip
1) Cleft extends through upper lip
- Often clefting of the nose and/or maxilla
- Lack of fusion between maxillary prominence and medial nasal prominence
37
Thymus formation
Formed via ventral portion of 3rd pouch
38
What will the Maxillary Prominences give rise to?
1) Surface of upper lip
2) Portions of maxilla
3) Secondary Palate
39
What are nasal placodes
Primordia or nasal epithelium
40
Thyroid Formation
1) First endocrine gland to develop
2) Divides into right/left lobes connected by the isthmus
3) Definitive shape by 7th week and thyroglossal duct will degenerate
41
What boundary do mandibular prominence form?
Caudal Boundary of Stomodeum
42
How is the Opening of the Pharyngotympanic tube achieved
1) Levator Veli Palatine
2) Tensor Veli Palatine
3) Salpinopharyngeus
43
Sensorineural hearing loss
Reduction in sound level and/or fidelity due to damage to inner ear or auditory n.; affects hearing at different frequencies and intensities
44
Internal Cervical Sinus
1) Persistence of 2nd pouch
- Rare
- Open into tonsillar sinus or near palatopharyngeal arch
45
Name of Cartilage of PA1
Merkel's Cartilage
46
Glossoschissis
Incomplete fusion of lateral lingual swellings resulting in a bifid tongue
47
Trigeminal N. supplies which arch?
1st PA
48
Describe the micro anatomy of a maculae
1) Cluster hair cells w/ stereocilia w/ overlying gelatinous material called otolithic membrane
2) Otolithic membrane covered w/ calcium carbonate/protein crystals called otoconia
49
What are the branchial anomalies
1) External Cervical Sinus
2) Internal Cervical Sinus
3) Cervical Cysts
4) Cervical Fistula
50
PA6 gives rise to which muscles
Intrinsic muscles of the larynx
51
List the Facial Primordia
1) Maxillary Prominences
2) Mandibular prominences
3) Frontonasal Prominence
52
Cervical Fistula
1) Canal that opens into tonsillar sinus and external side of the neck
- Persistence of parts of 2nd groove and pouch
- Ascends through subcutaneous tissue and platysma to reach carotid sheath; passes between carotids and opens into tonsillar sinus
53
PA3 gives rise to what muscle
Stylopharyngeus
54
DiGeorge Syndrome
1) Agenesis of Thymus and Parathyroid Glands
2) Shortened philtrum of upper lip, low-set and notched ears
3) Cardiac abnormalities (Defects of the aortic arch and heart)
55
Describe the Craniosynostosis
1) Scaphocephaly: Premature closure of sagittal suture --> cranium becomes long, narrow, and wedge shaped
2) Brachycephaly: Premature closure of the coronal suture --?> high, tower-like cranium
3) Plagiocephaly: Premature closure of coronal suture on one side --> cranium is twisted and asymmetric
4) Trigonocephaly: Premature closure of the frontal (metopic) suture --> malformation of frontal and orbital bones
56
Birth Defects are common with which groove?
2nd Groove
57
Conductive Hearing Loss
1) Effects outer or inner ear
| - Fluid build up in middle ear; otitis excessive wax, otosclerosis
58
What are the results of MNP fusion
a. Premaxillary part of maxilla
b. Primary Palate
c. Philtrum of Upper Lip
59
Meniere's Syndrome
Experience Dizziness, vertigo, high-pitched rushing or roaring sound (tinnitus) and fluctuating hearing loss
60
Paraxial Mesoderm gives rise to what?
Populates each arch to form PA musculature
61
What establishes continuity between side of nose (LNP) and cheek region
Fusion of LNP and Maxillary Prominences at the Nasolacrimal groove
62
Action of Stapedius
1) Tightens annular ligament attaching to window
| 2) Reduces oscillatory range and prevents excessive movement of stapes
63
External Ear Function
Collecting sound and transmitting it to ME via TM
64
Agenesis of Thyroid Gland
Absence of a thyroid gland or one of its lobes (rare)
65
Otitis Media
1) Ear-ache w/ possible fluid or pus in middle ear due to inflammation or infection
- Tympanic membrane appear red and bulged
- Untreated can impair hearing and scarring or auditory ossicles
66
Cleft Palate
1) Clefts of secondary palate to incisive fossa
- May involve uvula and/or hard and soft palates
- Lack of fusion between: Lateral Palatine Process w/ nasal septum and lateral palatine processes w. median palatine process
67
Middle Ear Physical
Known as Tympanic Cavity and is bounded by walls
68
Microglossia
Abnormal small tongue (rare) and usually associated with micrognathia
69
Primary Palate Formation
1) MNP fusion --> Median palatine process (primary palate)
- Between maxillary prominences
- Forms Premaxillary part of the maxilla
70
Tonsils formation
2nd Pouch --> Palatine Tonsils
71
Tensor Tympani O and I
O: Pharyngotympanic Tube, Greater Sphenoid, and petrous part of temporal bone
I: Handle of Malleolus
72
Sensorineural Hearing Loss is related to what?
1) Age and Noise
73
Pierre Robin Sequence
1) Hypoplasia of mandible, cleft palate, and defects of the eyes and ears
2) Micrognathia --> results in posterior displacement of the tongue --> obstruction of full closure of the palate --> results bilateral cleft palate
74
Tympanic Membrane Function
Moves w/ sound and transmits to ossicles
75
Innervation of Tensor Tympani
CN V3
76
1st Pharyngeal Pouches
1) Expands into tubotympanic recess --> cavity and mastoid antrum
2) Elongates to form pharyngotympanic tube
- Tympanic Membrane is formed by the 1st membrane + intervening mesenchyme
77
What are the components of the PA's
1) Ectoderm ~ Externally
2) Mesoderm (Paraxial) and Mesenchyme (NCC aggregates) ~ Core
3) Endoderm ~ internally
78
Glossopharyngeal N Supplies which arch?
3rd PA
79
Pharyngotympanic Tube (Eustachian Tube)
Equals pressure between nasopharynx and tympanic cavity
80
How do nasal pits arise
From proliferation of nasal placodes edges
81
NCC Derived Mesenchyme
Forms all CCT in head, including the dermis and smooth muscle
82
List all the muscles that are derived from PA2
1) Buccinator
2) Auricular Muscles
3) Occipitofrontalis
4) Posterior Belly of Digastric
5) Stylohyoid
6) Stapedius and Platysma
83
Merkel's Cartilage Forms What?
1) Dorsal --> Malleus and Incus
2) Ventral forms Primordium of mandible
3) Perichondrium --> Anterior ligament of malleus and sphenomandibular ligament
84
Muscles of mastication are derived from what?
PA1
85
Secondary Palate
1) Develops from Lateral Palatine Process
| - Lateral Palatine Process (Palatine shelves( Develops from mesenchyme of MXP
86
What does the External Ear consist of?
1) Auricle
2) External Acoustic Meatus
3) Tympanic Membrane
87
What will nasal puts derive?
Nostrils (nares)
| Nasal cavities
88
What are the two parts of the middle ear
1) Tympanic Cavity Proper
| 2) Epitympanic Recess
89
Ampullae
1) At the ends of the semicircular canals
| 2) Sensory structure detecting rotational acceleration
90
2nd Pouch
1) Forms Tonsillar Sinus
2) Mesenchyme forms lymphoid nodules of palatine tonsils
3) Endoderm will form tonsillar epithelium
91
PA4 gives rise to which muscles
1) Cricothyroid
| 2) Pharyngeal Constrictors
92
External Cervical Sinus
1) Failure of 2nd groove and cervical sinus to obliterate
- Detected due to discharge of mucus
- Commonly associated w/ auricular sinuses
93
What are the muscular components derived from?
Paraxial Mesoderm
94
Inner Ear Structure
1) Bony and Membranous Labyrinth
- Bony: Semicircular Canals, Vestibule, and Cochlea
- Membranous: w/in bony labyrinth consisting of tubules and sacs
95
Describe the TM
1) Concave w/ umbo tip pointing toward EAM
| - External = stratified squamous
96
What is the location of nasal placodes?
Frontonasal Prominence (FNP)
97
Describe the middle ear cavity wall
1) Tegmental wall (roof) formed via tegmen tympani (temporal bone)
2) Jugular Wall (floor) ~ separates middle ear from internal jugular vein
3) Membranous wall (lateral)~ formed mostly via tympanic membrane 4) Labrinthine wall (medial)~ Separates middle from inner ear
- Prominence of semicircular wall
- Oval and Round Windows
5) Carotid wall (anterior)~ Separates tympanic cavity from carotid canal and artery
- Opening for pharyngotympanic tube and canal for tensor tympani
6) Mastoid Wall (Posterior)~ connects tympanic cavity to mastoid air cells
- Opening is call the aditus
- Anterior Ligament of Malleus attaches malleus to the post. wall
98
What is the Scala Vestibuli associated with
Oval Window
99
What is the primordial jaws?
1st PA
100
What forms all the CT in head, including dermis and smooth muscle
Mesenchyme
101
Cervical Cysts
1) Remnants of cervical sinus and/or 2nd groove
- Slowly enlarging, painless, free-lying cyst in the neck, inferior to angle of the mandible
- Accumulation of fluid and cellular debris
102
What will the lateral nasal prominence produce
Alae (sides) of nose
103
Where is the Organ of Corti located at?
floor of scala media resting on basilar membrane
104
Stapedius O and I
O: Pyramidal eminence of posterior wall
I: Stapes
105
Innervation of Stapedius
CN VII
106
What is Meniere's Syndrome associated with?
Increase endolymph volume leading to abnormal signaling
107
Name of Cartilage of PA2
Riecherts
108
List two first arch syndromes
Treacher-Collins Syndrome
Pierre Robin sequence
109
Describe Pharyngeal Pouches
Located internally as part of the pharynx, covered with endoderm
110
Ankyloglossia
Frenulum is fort and extends to the tip of the tongue
111
Vagus N. Supplies which arch?
4th - 6th PA
112
What boundary do maxillary prominences form?
Lateral boundaries of stomodeum
113
Parathyroid Formation
```
3rd = inferior parathyroid gland
4th = superior parathyroid gland
```
114
PA1 gives rise to which muscles?
1) Temporalis
2) Masseter
3) Pterygoids
4) Mylohyoid
5) Anterior Belly of Digastric
6) Tensor Veli Palatini
7) Tensor Tympani
115
Macroglossia
Excessively large tongue caused by generalized hypertrophy
| - often seen in infants with down syndrome
116
Ruptured Ear Drums
Due to abnormal increase in medial ear pressure via fluid or barotrauma or external trauma
117
Describe how the 2nd - 4th Pharyngeal grooves disappear
1) 2nd Pharyngeal Arch is going to extend down to overlap with 3rd and 4th
2) Forms a cervical sinus which eventually obliterate grooves 2-4 w/ fusion
118
What structures amplify the External Signal
Auditory Ossicles
119
Vertigo
Sensation of feeling dizzy and off balance
120
What is the Scala Tympani associated with
Round window
121
Pharyngeal membranes
Located between the Groove and Pouch
122
Facial N. supplies which arch?
2nd PA
