Head And Neck Session 3 Flashcards Preview

Semester 4 > Head And Neck Session 3 > Flashcards

Flashcards in Head And Neck Session 3 Deck (114):
1

What does the facial skeleton arise from?

Neural crest cell infiltration of the mesenchyme core of PA1

2

Where do the muscles of mastication originate from?

Mesoderm of PA1

3

Where do the muscles of facial expression arise from?

Mesoderm of PA2

4

What are neural crest cells?

Specialised population of cells that originate in the neuroectoderm upon induction by the neural tube (4th germ lineage)

5

What happens to neural crest cells at the lateral border after being induced by the neural tube?

Displace and ente mesoderm instead of becoming CNS. Then migrate throughout body to give rise to many structures

6

What are the external features that derive from the FNP?

Forehead, bridge of nose, nose and philtrum

7

What is located at the base of the stomatodeum?

Buccopharyngeal membrane

8

What is the external feature that derives from the stomatodeum?

Oral fissure

9

Where do the cheeks, lateral upper jaw and lip derive from?

Maxillary prominence of PA1

10

What arises from the mandibular prominence of PA1?

Lower lip and jaw

11

Describe the process of formation of the nose.

Nose placodes appear on FNP and sink to form nasal pits --> medial and lateral prominences on either side of pit are pushed together by maxillary prominence moving medially --> maxillary fuse with medial nasal --> medial prominences fuse in the midline

12

What does fusion of the medial nasal prominences create?

Intermaxillary segment consisting of labial component, philtrum, upper jaw, 4 incisors and primary palate

13

What is the main part of the definitive palate?

Secondary palate

14

Where is the secondary palate derived from?

Palatial shelves of maxillary prominences

15

How is the secondary palate formed?

Palatal shelves grow vertically downwards into oral cavity either side of tongue --> mandible enlarges --> tongue drops --> palatal shelves fuse in the midline

16

What initially separates the nasal pit and oral cavity but quickly degenerates?

Oronasal membrane

17

How does the nasal septum form?

Mid-line down growth that fuses with palatal shelves

18

What is the cause of lateral cleft lip?

Failure of fusion of medial nasal prominence and maxillary prominence

19

What is the cause of lateral cleft lip involving the primary palate?

Failure of fusion of medial nasal prominence and maxillary prominence

20

What is the cause of cleft lip and cleft palate?

Failure of fusion of medial nasal prominence and maximally prominence combined with failure of palatal shelves to meet in the midline

21

What are the consequences of cleft lip and left palate?

Difficulty suckling and with speech

22

What is the fate of the FNP?

Forehead, bridge of nose and medial and lateral nasal prominences

23

What is the fate of the medial nasal prominence?

Philtrum, primary palate and mid upper jaw

24

What is the fate of the lateral nasal prominence?

Sides of the nose

25

What is the fate of the maxillary prominence?

Cheeks, lateral upper lip, secondary palate and lateral upper jaw

26

What is the fate of the mandibular prominence?

Lower jaw and lip

27

When does development of the eyes begin?

In the 4th week at the3-vesical brain stage

28

How do the eyes develop?

Forebrain pouches grow outwards --> met overlying ectoderm (optic placodes) --> optic placode invaginates and pinches off

29

What forms the lens of the eye in the developed foetus?

Optic placodes

30

Where does the retina derive from?

Diencephalon (forebrain) as part of the optic vesicle

31

What transforms to give the optic nerve?

Optic stalk

32

What causes humans to have binocular vision?

Growth of facial prominences pushing eye primordia from the side of the head to the front of the face

33

What do all common chromosomal abnormalities have associated anomalies with?

External ear

34

What arises in the neck to form the external ear?

External auditory meatus from 1st pharyngeal cleft and auricles from proliferation of PA1&2 surrounding meatus

35

What causes ascension of the ears from the neck to be in line with the eyes on the sides of the head?

Mandible growth

36

How is the inner ear formed?

Otic placodes invaginate to form auditory vesicles and membranous labyrinth forms cochlea and semi-lunar canal system

37

What is foetal alcohol syndrome?

Exposure of the developing foetus to alcohol causing disruption to neural crest cell migration and brain development causing characteristic facial features and severe restriction of cognitive development

38

What is alcohol-related neurodevelopment disorder (ARND)?

CNS, behavioural and learning dysfunction due to alcohol exposure in utero without characteristic facial features of FAS

39

What are the characteristic facial features seen in FAS?

Short palpebral fissure lengths
Smooth philtrum
Thin upper lip
Short, upturned nose
Microcephaly

40

What is the incidence of FAS and ARND?

1 in 100 births

41

What drives development of the face?

Expansion of the cranial neural tube, appearance of complex tissue systems, development of sense organs and need to separate resp from GI tracts

42

What is the function of the cervical spine?

Support skull, allow a large range of movement, provide passage for descending nerves

43

What type of curvature does the cervical spine have?

Secondary

44

What ligaments support the cervical spine?

Anterior and posterior longitudinal
Ligamentum flavum
Interslinous ligament
Nuchal ligament
Transverse ligament of atlas

45

Where are the anterior and posterior longitudinal ligaments positioned?

Along bodies and discs of the vertebral column

46

What does the ligamentum flavum connect?

Laminae of adjacent vertebrae along length of vertebral column

47

What does the inter spinous ligament connect?

Adjacent spinous processes along length of vertebral column

48

Describe the nuchal ligament.

Continuation of supraspinous ligament to C1-7 spinous tips giving attachment for rhomboids and trapezius

49

What does the transverse ligament of atlas connect?

Lateral masses of atlas to anchor dens in place

50

What are the characteristic features of C1?

No body, no spinous process

51

Where does the vertebral artery pass in relation to C1?

Through groove, not transverse foramen

52

What movement of the head does C1 facilitate?

Nodding

53

What movement of the head does C2 facilitate?

Shaking

54

What are the characteristics of C2?

Dens/odontoid peg and bifilar spinous process

55

Why do cervical vertebrae have characteristic large vertebral foramen?

For passage of the vertebral artery

56

What are the characteristic features of C7?

Prominent, easily palpable non-bifid spinous process and large transverse process

57

Where do the vertebral artery, vein and nerves run in relation to C7?

Vertebral artery around vertebra, vein and nerves pass through the foramen

58

Which ligaments are unique to the cervical spine?

Nuchal and transverse ligament of atlas

59

Which 3 lines of reference can be used to see if the cervical vertebrae are in alignment?

Anterior vertebral bodies
Posterior vertebral bodies
Spinolaminar

60

What forms the spinolaminar line?

Point at which the spinous process and lamina fuse

61

What is Jefferson's fracture?

Vertical fall on extended neck --> compression of lateral masses between occipital condyles and axis causing fracture of anterior and poster arches

62

Why is spinal cord damage at C1 level unlikely in burst/Jefferson fracture?

Large vertebral foramen

63

What is hangman's fracture?

Hyperextension of head and neck --> compression of spinal cord and lower brainstem

64

What is the definition of the skull?

Cranium and mandible formed by 22 discrete flat bones joined by fibrous joints (sutures) with the only moveable joint being the TMJ

65

What can the cranium be divided into?

Clavarium (roof) and cranial base

66

Which bones form the calvarium?

Frontal
Occipital
2 parietal bones

67

Which bones form the cranial base?

Frontal
Sphenoid
Ethmoid
Occipital
Parietal
Temporal

68

What is the purpose of them many foramina present in the skull?

Allow entry of sensory nerves, arterial supply to the brain and meninges, sympathetic fibres and venous blood.
Allow exit of cranial motor nerves, PS outflow, veins and lymph

69

What is the cribiform plate?

Part of ethmoid bone at top of nasal sinuses with lots of foramina allowing passage of CNI

70

What is the optic foramen?

Located at the back of the eye socket allowing passage of CNII

71

What is the superior orbital fissure?

At the rear of the eye socket in the sphenoid bone allows passage of CNIII, IV and V

72

What is the foramen rotundum?

Opening in the middle of the skull allowing passage of CNV maxillary branch

73

What is the foramen ovale?

Opening in the base of the skull that allows passage of the mandibular branch of CNV

74

What is the stylomastoid foramen?

Opening at the base of the skull allowing passage of CNVIII

75

What is the hypoglossal canal?

Opening at the base of the skull in the occipital bone allowing passage of CNXII

76

What is the jugular foramen?

Opening at the base of the skull bounded by the temporal and occipital bones allowing passage of CNIX, X and XI

77

What is the contents of the foramen magnum?

Medulla oblongata, meninges, spinal roots of accessory nerve, vertebral arteries, anterior and posterior spinal arteries, tectorial membrane and alar ligaments

78

Why is the cranial floor likely to fracture in high energy impact to the head?

Foramina weaken it

79

What are the functions of the skull?

Enclose and protect brain and special sense organs, creates cranial cavity and provide site of attachment for muscles and meninges

80

What forms the meninges?

Periosteal layer of dura mater

81

Where is the cranium thick?

Occipital and frontal bones

82

What are the layers of the cranium?

Inner plate of cortical bone, middle layer of spongy bone (diploe), outer compact bone layer

83

What are the cavities of the skull?

Orbit, cranial cavity, nasal cavity, paranasal sinuses, oral cavity, auditory canal

84

Describe the structure of the mandible.

L&R mandibles joined by midline fibrous joint called the mental symphysis

85

What is found at the mental symphysis?

Many foramina

86

What does the condylar process of the mandible articulate with?

Skull

87

What are the three divisions of the cranial fossa/floor/base and what do they contain?

Anterior: CNI and part of CNII
Middle: CNII-VII
Posterior: CNVII-XII

88

What are the three lines that divide the calvaria?

Coronal suture line, sagittal suture line and lamboid suture line

89

What is bregma?

Point of intersection of the coronal and sagittal suture lines

90

What is lambda?

Point of intersection of sagittal and lamboid suture lines

91

What does the frontal bone form?

Anterior part of skull vault, upper border of orbital margins and orbit roof

92

Where is the ethmoid bone found?

Midline of anterior cranial fossa

93

What gives the ethmoid bone a serrated appearance?

Passage of olfactory nerve fibres

94

What can fracture of the ethmoid bone lead to?

Anosmia

95

What are the notable features of the ethmoid bone?

Cribiform plate, crista galli, ethmoid bulla, ethmoid air cells

96

Where are the olfactory bulbs located?

Either side of crista galli

97

What are the components of the sphenoid bone?

Central body, greater wing, lesser wing and pterygoid process

98

Where is the sphenoid bone located?

Upper nasal cavity associated with the pituitary and hypothalamus

99

What does the body of the sphenoid bone form?

All of the median middle cranial fossa

100

What are the notable features of the sphenoid body?

Optic groove, tuberallum sellae, sella turcica, dorsum sellae with posterior clinoid process, clivus

101

What does the parietal bone form?

Large part of side and roof of the cranial cavity

102

What does the internal surface of the parietal bone have?

Grooves of MMA, sagittal sulcus, granular pits from CSF valves and grooves for the sigmoid sinus

103

What are the 6 parts of the temporal bone?

Squamous, mastoid, tympanic, styloid process, zygomatic process and petrous part

104

What is the importance of the temporal bone?

Senses of hearing and balance and passage of the facial nerve

105

Which part of the temporal bone is involved in the inner auditory meatus?

Petrous part

106

What are the four parts of the occipital bone found around the foramen magnum?

Squamous, L&R condylar and basilar

107

What do each of the four parts of the occipital bone form?

Squamous: posterior vault
L&R condylar: edges of foramen magnum
Basilar: anterior foramen magnum

108

What holds together bones in the neonatal skull?

Thick CT matrix

109

Why are the bones of the skull not joined by sutures in the neonate?

To allow for movement of the cranial bones during the birthing process

110

Why does the neonatal skull not collapse during the child birth process?

Serrated bone edges temporarily interlock

111

What is the risk to the neonatal skull in pre-term birth?

Sutures too wide therefore no interlocking of bones causing high probability of brain damage during the normal birthing process

112

What are bregma and lambda known as in the neonatal skull?

Anterior and posterior fontanelles

113

Are the proportions between the cranium and facial skeleton the same in the neonate and adult?

No

114

How many bones articulate to form the facial skeleton?

14