Head And Neck Session 10 Flashcards Preview

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Flashcards in Head And Neck Session 10 Deck (162):
1

What does the pituitary gland sit within?

Sells turcica

2

Why is an alternate name for the pituitary gland hypophysis Cerebri?

It is an extension of the cerebrum

3

What type of embryonic tissue forms the posterior pituitary gland?

Neuroectoderm

4

What type of embryonic tissue forms the anterior pituitary gland?

Ectoderm

5

What is Rathke's pouch?

Outpouching of stomatodeum

6

Describe the development of Rathke's pouch.

Grows dorsally, losing connection with oral cavity by the end of the 2nd month

7

What happens to the anterior wall cells of Rathke's pouch?

They proliferate rapidly to form the anterior pituitary lobe and pars tuberalis

8

Describe the growth of pars tuberalis.

From anterior wall cells of Rathke's pouch growing along stalk of infundibulum to surround it

9

What happens to the posterior wall cells of Rathke's pouch?

Form pars intermedia

10

Does pars intermedia have significance in humans?

No

11

What is the infundibulum in pituitary gland development?

Downward extension of the diencephalon

12

In which direction does the infundibulum grow in pituitary gland development?

Down towards the roof of the pharynx

13

What does the infundibulum form in pituitary gland development?

Posterior lobe and stalk

14

What are the posterior lobe and stalk of the pituitary made up of?

Neurological cells and nerve fibres from the hypothalamic area

15

When does the primordia of the pituitary gland arise?

Third week

16

When does the primordia of the tongue arise?

4th week (at the same time as the palate)

17

Do all of the pharyngeal arches contribute to the development of the tongue?

Yes

18

What are the contributions from PA1 to the tongue?

2 lateral swellings and 1 median swelling (tuberculin impar)

19

Describe the development of the PA1 contributions to tongue development.

2 lateral swellings overgrow tuberculum impar and merge together to form the body of the tongue

20

What is the cupola in tongue development?

Mesenchyme proliferation from PA2, 3 &4

21

Describe the development of cupola.

Tissue from PA3 overgrows that of PA2 to form the root of the tongue

22

What is the contribution of PA4 to the development of the tongue?

Forms epiglottal swelling to create the epiglottis and extreme posterior portion of the tongue

23

What provides general sensory innervation to the body of the tongue?

CNV3 and glossopharyngeal

24

What explains the general sensory innervation of the body of the tongue?

The majority of its mucosa comes from PA1&3 therefore cranial nerves associated with these dominate

25

What gives general sensory innervation to the root of the tongue?

Glossopharyngeal and vagus

26

What gives general sensory innervation to the epiglottis and extremes posterior part of the tongue?

Superior laryngeal nerve

27

Why does chorda tympani give special sensory innervation to the body of the tongue despite not being the cranial nerve associated with PA1?

It passes into the arch through the middle ear

28

What gives special sensory innervation to the root of the tongue?

Glossopharyngeal

29

Why is the motor innervation of the tongue provided by the hypoglossal nerve?

Intrinsic and extrinsic myogenic precursors arise in occipital somites and migrate to the tongue, taking their innervation with them

30

What marks the border between the body and root of the tongue?

Sulca terminalis

31

Where does the primordium of the thyroid gland arise?

In the floor of the pharynx between tuberculum impar and copula

32

How is the origin of the thyroid gland seen in the adult?

Foramen cecum

33

Describe the descent of the thyroid primordium.

In front of pharyngeal gut tube, hyoid bone and laryngeal cartilages connected to the tongue by the thyroglossal duct

34

What does the thyroglossal duct connect?

Isthmus of thyroid with tongue

35

What forms the pyramidal lobe of the thyroid gland seen in 50% of the population?

Remnant of thyroglossal duct at isthmus

36

When does the thyroid gland reach its final position?

7th week

37

When does the thyroid gland become functional?

End of the 3rd month

38

What provides follicular cells to the thyroid gland?

Thyroid diverticulum

39

What provides parafollicular cells to the thyroid gland?

Ultimobranchial body of 4th PA

40

What is a thyroglossal cyst?

Fluid filled pouch found anywhere along the thyroglossal duct due to failure of closure

41

Where in the neck will a thyroglossal cyst present?

Near or in the midline

42

Where are 50% of thyroglossal cysts found?

Close of just inferior to the hyoid bone

43

What is a thyroglossal fistula?

Connection of a thyroglossal cyst to the outside by a fistulas canal

44

What is a thyroglossal cysts usually secondary to?

Cyst rupture

45

What is aberrant thyroid tissue?

Functioning thyroid tissue found anywhere along the line of descent that is subject to the same diseases as the thyroid itself

46

Where is aberrant thyroid tissue commonly found?

Just behind foramen cecum

47

Why does neural crest cell defects cause both craniofacial and cardiac abnormalities?

They are essential for craniofacial and normal conotruncal endocardial cushion development

48

What cardiac abnormalities are commonly seen in neural crest cell defects?

Persistent turn us arteriosus, tetralogy of Fallot, transposition of the great vessels

49

Neural crest cells are a particularly vulnerable population of cells. What are they easily killed by?

Alcohol, retinoic acid

50

What is Treacher-Collins syndrome?

Autosomal dominant condition causing hypoplasia of the mandible and facial bones, down slanting palpebral fissure, lower eyelid colobomas and malformed external ears

51

What is the genetic defect in Di-George syndrome?

Deletion of long arm of chromosome 22

52

Describe the spectrum of disorders seen in Di-George syndrome.

Congenital heart defects, mild facial dysmorphology, learning disabilities and frequent infections

53

Why do Di-George patients suffer from frequent infections?

Thymic hypo-/aplasia disrupting T-cell mediated responses

54

Why might hypocalcaemic seizures be seen in Di-George syndrome?

Parathyroid dysfunction due to disruption of endodermal-mesenchymal interaction

55

What is CATCH-22?

Deletion of long arm of chromosome 22 causing:
Cardiac abnormality
Abnormal fancies
Thymic aplasia
Cleft palate
Hypocalcaemia/ hypoparathyroidism

56

What is the defect in CHARGE Syndrome?

CHD7 heterozygous mutation causing impaired production of multipotent neural crest cells

57

How does CHARGE Syndrome present?

Coloboma, heart defect, atresia of choanae, retardation of growth and development, genital hypoplasia, ear defects

58

What are the cellular implications for CHARGE syndrome?

Deficiency of mesoderm formation and neural crest cell dysfunction

59

What is the type of genital hypoplasia seen in CHARGE syndrome?

Hypogonadotrophic hypogonadism

60

What is the general implication for embryological development in CHARGE syndrome?

Arrest of embryological differentiation in the 2nd month

61

What is the pharynx?

Muscular tube hanging from the skull to the opening of the oesophagus

62

What anatomical landmark can be used to identify the opening of the oesophagus?

Cricoid cartilage

63

What gives motor innervation to the pharynx?

CNVII, IX, X and XII

64

What provides sensory innervation to the oropharynx?

CNV2

65

What is the sensory innervation of the oropharynx?

CNIX

66

What is the sensory innervation to the laryngopharynx?

CNXII

67

What are the borders of the nasopharynx?

Superior: skull base
Inferior: level of soft palate
Anterior: posterior choanae
Posterior: nasopharyngeal tonsil and C1 vertebral body

68

What is the function of the nasopharynx?

Condition inspired air

69

What lines the nasopharynx?

Ciliated stratified squamous epithelium

70

What are the contents of the nasopharynx?

Nasopharyngeal tonsil, Eustachian tube orifice, tubal tonsil

71

Where is the tubal tonsil located?

In the submucosa of the lateral wall of the pharynx at the Eustachian tube orifice

72

What landmark can be used to identify the level of the C1 vertebra?

Hard palate

73

What landmarks can be used to identify the C2 and C3 vertebral levels?

Angle of mandible and hyoid bone

74

What landmarks can be used to identify the levels of C4-6 vertebrae?

Upper thyroid cartilage, lower thyroid cartilage, cricoid cartilage

75

What are the borders of the oropharynx?

Superior: level of soft palate
Inferior: superior edge of epiglottis
Anterior: oral cavity
Posterior: C2 and C3 vertebral bodies

76

What is the function of the oropharynx?

Digestion

77

What lines the oropharynx?

Stratified squamous epithelium

78

What are the contents of the oropharynx?

Palatine tonsils, anterior and posterior pillars

79

What are the palatine tonsils?

Collections of lymphoid tissue encapsulated by squamous epithelium with crypts that form part of Waldeyer's ring

80

What forms the submucosal tonsillar bed of the palatine tonsils?

Superior pharyngeal constrictor and pharyngobasilar fascia

81

Why do the palatine tonsils not fill the tonsillar sinus in adults?

Due to post-puberty atrophy

82

What gives innervation to the palatine tonsils?

CNV2 and CNIX

83

What gives arterial supply to the palatine tonsils?

Tonsillar branch of facial, lingual, ascending palatine and ascending pharyngeal

84

What gives venous drainage to the palatine tonsils?

Pharyngeal plexus and para tonsillar vein

85

Where does lymphatic drainage of the palatine tonsils flow?

Pierces superior constrictor to reach jugulo-digastric

86

What forms the anterior pillar in the oropharynx?

Palatoglossal muscle between the buccal cavity and oropharynx fusing with the lateral wall of the tongue

87

What forms the posterior pillar in the oropharynx?

Palatopharyngeus muscle blending with the constrictor muscles of the pharynx wall

88

What gives arterial supply to the pharynx?

Superior thyroid, ascending pharyngeal, ascending and descending palatine, branches of lingual, facial and maxillary

89

What provides venous drainage to the pharynx?

Pharyngeal venous plexus into the IJV

90

What are the borders of the laryngopharynx?

Superior: superior edge of epiglottis
Inferior: level of inferior edge of cricoid cartilage
Anterior: larynx
Posterior: C3-6 vertebral bodies

91

What is the function of the laryngopharynx?

Open inferior to the oesophagus and larynx

92

What lines the laryngopharynx?

Stratified squamous epithelium

93

What forms the paoterior and lateral walls of the laryngopharynx?

Externally middle and inferior constrictor muscles, internally Palatopharyngeus and stylopharyngeus

94

What forms the Piriform fossa?

Ary-epiglottic fold, thyroid cartilage, thyrohyoid membrane

95

Where is the Piriform fossa located?

Either side of the laryngeal inlet

96

What is the clinical relevance of the Piriform fossa?

Internal and recurrently laryngeal nerves run deep to it and are vulnerable to damage if a foreign body becomes lodged

97

What does the median raphe provide?

Point of attachment for constrictor muscles of pharynx

98

Give the arrangement of the external circular layer of the pharynx from superior to inferior.

Pharyngobasilar fascia, superior constrictor, greater hyoid bone, middle constrictor and inferior constrictor

99

What are the facial layers of the external circular layer of the pharynx?

Strong internal pharyngobasilar fascia and thin external buccopharyngeal fascia

100

What is the buccopharyngeal layer of fascia continuous with?

Pretracheal layer of deep cervical fascia

101

What is the function of the external circular layer muscles in the pharynx?

Sequentially contract involuntarily to propel food to oesophagus

102

Which muscles form the internal longitudinal layer of the pharynx?

Salpingopharyngeus, Palatopharyngeus and stylopharyngeus

103

Which structures pass in the gap superior to the superior constrictor muscles of the pharynx?

Levator veli palatini, ET, ascending palatine artery

104

Which structures pass in the gap superior to the middle constrictor muscles of the pharynx?

Stylopharyngeus, CNIX, stylohyoid ligament

105

Which structures pass in the gap superior to the inferior constrictor muscles of the pharynx?

Internal laryngeal nerve, superior laryngeal artery and vein

106

Which structures pass in the gap inferior to the inferior constrictor muscles of the pharynx?

RLN, inferior laryngeal artery

107

Where is the pharyngeal nerve plexus found?

Lying mainly on middle constrictor

108

What forms the pharyngeal plexus?

CNIX and X with sympathetic branches from the superior cervical ganglion

109

What are the 3 phases of swallowing?

Oral, pharyngeal and oesophageal

110

Describe the oral phase of swallowing.

Voluntary, bolus compressed against palate by tongue and pushed to oropharynx by tongue and soft palate musclature

111

Describe the pharyngeal phase of swallowing.

Involuntary and soft palate rises to seal of laryngopharynx from naso- and oropharynx whilst the pharynx widens and shortens

112

What muscles are involved in the pharyngeal phase of swallowing?

Suprahyoid and longitudinal pharyngeal muscles

113

What is the action of the muscles in the pharyngeal phase of swallowing?

Elevate larynx

114

Describe the oesophageal phase of swallowing.

Involuntary sequential contraction of all 3 pharyngeal constrictor muscles to create peristaltic ridge

115

What protects the larynx during swallowing?

Overhanging tongue, epiglottis and vocal cords

116

What is the problem with the arrangement of the pharynx with respect to the oesophagus and larynx?

Food and air have to cross over in oropharynx to enter correct structure

117

What do the nasopharyngeal tonsils produce?

IgA, IgG and IgM

118

When are the adenoids maximal in size?

Between 3 and 8 y.o.

119

What causes enlargement of the adenoids?

Viral or bacterial infection

120

What are the consequences of adenoid enlargement?

Nasal obstruction, ET obstruction

121

What can nasal obstruction lead to?

Mouth breathing causing feeding difficulty, hyponasal speech, snoring, obstructive sleep apnoea

122

What can ET obstruction lead to?

Recurrent otitis media, chronic otitis media with effusion

123

What is obstructive sleep apnoea?

Spectrum from mild snoring to OSA due to partial/complete airway obstruction causing turbulent airflow

124

What are the S/S of OSA?

Daytime tiredness, hypoxia, increased CVS strain

125

How can the adenoids be visualised?

Post-nasal space X-ray, post-nasal mirror, fibre optic endoscope, in theatre

126

What are post nasal space X-rays no longer used to visualise the tonsils?

Radiation exposure to children

127

What are the possible complications of adenoidectomy?

Bleeding, Atlanto-occipital joint dislocation due to infection, ET stenosis

128

What is the 5-year survival rate for nasopharyngeal carcinoma?

80%

129

Where are nasopharyngeal carcinomas most commonly found?

Lateral nasopharyngeal recess

130

What is associated with the undifferentiated form of nasopharyngeal carcinoma?

EBV infection

131

What are the risk factors for nasopharyngeal carcinoma?

Chinese ancestry, EBV exposure, heavy alcohol intake

132

What are the S/S of nasopharyngeal carcinoma?

Nasal obstruction, blood-tinged discharge, tinnitus, sore throat, unilateral conductive hearing loss

133

Does naopharyngeal carcinoma usually present early or late?

Late

134

How is nasopharyngeal carcinoma managed?

Staged by TNM and treated with radiotherapy (limited role for chemotherapy and surgery)

135

Why is tonsillectomy no longer carried out as frequently as it was historically?

Disorders of palatine tonsils tend to lessen in severity and frequency as they atrophy with age

136

What are the indications for tonsillectomy?

Recurrent tonsilitis (5/year in the last 2 years), previous peritonsillar abscess, suspected cancer, OSA

137

What techniques can be used in tonsillectomy?

Cold steel instruments, guillotine, electrosurgery, diathermy, radio wave

138

What are the complications associated with tonsillectomy?

General anaesthetic risks, primary and secondary bleeding, infection

139

Which vessel does primary bleeding in tonsillectomy usually arise from?

Tonsillar branch of facial artery

140

Which vessel does secondary bleeding in tonsillectomy usually arise from?

External palatine vein

141

What is pharyngeal pouch?

Relatively rare position herniation of pharyngeal mucosa through Kilian's dehiscence

142

Where is Kilian's dehiscence?

Between superior thyropharyngeus and inferior cricopharyngeus parts of infirm constrictor muscle of pharynx

143

What is the pathogenesis of pharyngeal pouch?

In swallowing the cricopharyngeus does not relax as the thyropharyngeus contracts causing an increase in intrapharyngeal pressure --> midline true diverticulum

144

What are the consequences of pharyngeal pouch?

Accumulation of food leading to dysphasia, regurgitation, halitosis,and even aspiration of pouch contents

145

What population is pharyngeal pouch typically seen in?

Elderly

146

What causes clinical challenges to the patency of the airway in children compared to the adult?

Head:body ratio, small face and mandible, large tongue and adenoids, soft and short trachea, high SA:weight ratio, lower respiratory reserve, high metabolic rate, complaint chest walls

147

How can the patency of the airway in children be examined?

Effort of respiration, pallor, cyanosis, haemangioma, auscultation, palpation, flexible nasal endoscopy, microlaryngoscopy, bronchoscopy

148

What causes the funnel shape of the airway in the child in comparison to the adult?

Narrow and underdeveloped cricoid cartilage

149

How does acute epiglottis present?

Septic, pyrexia, classic Tripod position: leaning forward and drooling

150

What are the usually causative agents of acute epiglottitis?

H influenzae, staphylococci, beta-haemolytic streptococci or pneumococci

151

Which age group does acute epiglottitis typically affect?

2-7 y.o.

152

How is acute epiglottitis treated?

Secure airway, take bloods and throat swabs, broad spectrum Abx (ceftriaxone) and steroids

153

What is the pathogenesis of laryngotracheobronchitis (croup)?

Initial viral infection of throat --> infective oedema narrowing subglottis --> harsh (barking) subglottis cough and stridor

154

How is mild croup treated?

Oral Abx and steam inhalation

155

How is moderate-severe croup treated?

IV Abx, humidified O2, adrenaline nebuliser

156

What is the leading cause of death in 1-3 y.o., especially in males?

Foreign body in airway

157

How does a foreign body in the airway typically present?

Hx of unwitnessed episode of choking, coughing or aging with foreign body --> vague S/S

158

What does radiology in foreign body in the airway investigation look for?

Opacity of object, segmental/lobar lung collapse, local emphysema and air trapping

159

How are foreign bodies and associated complications managed?

Remove item by bronchoscopy and use steroid and inhaled bronchodilators if there is oedema as a result

160

What is laryngomalacia?

Congenital dynamic lesion of laryngeal cartilage causing collapse of supra glottic structures on inspiration resulting in congenital stridor

161

What is the most common cause of congenital stridor?

Laryngomalacia

162

What are the Tx options for laryngomalacia?

Conservative or aryepiglottoplasty