Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

14. Head and Neck > 10. Development > Flashcards

10. Development Flashcards

1
Q

What proportion of the total length of the embryo do the head and neck make up at week 4?

A

1/2.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the pharyngeal arches?

A

A sequence of ridges that form in the lateral walls of the embryonic pharynx bulging into the lumen of the pharynx and to the outside as the future face and neck regions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What covers the pharyngeal arches internally and externally?

A

Internally - endoderm.

Externally - ectoderm.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the branchial arches separated by on the outside of the head?

A

Branchial clefts/grooves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the branchial arches separated by on the inside

A

Branchial pouches.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What does the branchial membrane separate?

A

The branchial grooves and pouches that meet end-on.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the cervical sinus?

A

The space created by a flap of tissue from the second arch that grows down to cover the third to sixth arches and grooves.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is in each branchial arch?

A

An artery, a vein, a cranial nerve, and some mesenchyme.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What forms the brain?

A

The anterior end of the neural tube.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the sections of the brain in the three vesicle stage?

A

Prosencephalon - forebrain.
Mesencephalon - midbrain.
Rhombencephalon - hindbrain.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are cranial nerves classified?

A

On the basis of function and their embryonic origin: somatic efferent, special sensory, nerves of the pharyngeal arches.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the four cranial nerves of the pharyngeal arches?

A

CN V (trigeminal), CN VII (facial), CN IX (glossopharyngeal), CN X (vagus).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which arch is the trigeminal nerve from?

A

1st.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the functions of the trigeminal nerve?

A

Principle sensory nerve of the head - skin of the face, lining of the mouth and nose.
Motor to muscles of mastication and mandibular process.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which arch is the facial nerve from?

A

2nd.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the functions of the facial nerve?

A

Motor to muscles of facial expression and muscles derived from 2nd pharyngeal arch.
Sensory - taste buds on anterior 2/3 of tongue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which arch is the glossopharyngeal nerve from?

A

3rd.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the functions of the glossopharyngeal nerve?

A

Motor - stylopharyngeus.

Sensory - general and special sensory to posterior 1/3 tongue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Which arches is the vagus nerve from?

A

4th and 6th.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the functions of the vagus nerve?

A

4th arch branch is superior laryngeal nerve - cricothyroid and constrictors of the pharynx.
6th arch branch is recurrent laryngeal nerve - intrinsic muscles of the larynx.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the arteries from each branchial arch?

A

1st, 2nd, and 3rd - common, external, and internal carotid arteries and branches.
4th - aortic arch, part of right subclavian artery.
6th - pulmonary arteries.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does the facial skeleton derive from?

A

Frontonasal prominence, 1st pharyngeal arch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What do the muscles of mastication derive from?

A

1st pharyngeal arch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What do the muscles of facial expression derive from?

A

2nd pharyngeal arch.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the cartilages that develop from pharyngeal arches?
``` 1st - Meckel's cartilage. 2nd - Reichert's cartilage. 3rd - Hyoid bone. 4th - Hypobranchial eminence (-> epiglottis). 4th and 6th - cartilages of the larynx. ```
26
What is Meckel's cartilage a template for?
Mandible by membranous ossification.
27
What do the pharyngeal pouches become?
1st -> eustachian tube and middle ear cavity. 2nd -> crypts of palatine tonsil. 3rd: dorsal part -> inferior parathyroid, ventral part -> thymus. 4th: dorsal part -> superior parathyroid, ventral part -> thyroid C cells.
28
What makes up the middle ear and what are they derived from?
Ossicles from cartilage bar derivatives, tympanic cavity and auditory tube from 1st pharyngeal pouch.
29
What is the fate of the pharyngeal clefts?
The 1st cleft remains but the 2nd one grows down to cover all the other so they go.
30
What is a possible result of failure to be obliterated of the cervical sinus?
Cysts of fistulae anywhere along the anterior border of the sternocleidomastoid.
31
What is the first evidence of facial development?
Appearance of a depression in the ectoderm on the ventral aspect of the head - the stomadaeum (site of the future mouth).
32
What are the five folds that form around the stomadaeum to form the face?
Frontonasal prominence, two maxillary prominences, and two mandibular prominences.
33
Where is the frontonasal prominence and what does it go on to form?
Superior in the midline. Forms the forehead, bridge of nose, upper eyelids, philtrum.
34
Where are the maxillary prominences and what do they go on to form?
Lateral, derived from 1st pharyngeal arch. Forms middle third of face, upper jaw, most of the lip, sides of the nose.
35
Where are the mandibular prominences and what do they go on to form?
Inferolateral, derived from 1st pharyngeal arch. Forms lower thirds of face, lower jaw, lip.
36
What do the facial prominences consist of?
Mesenchyme with a covering of ectoderm.
37
What is the first evidence of nose formation?
Appearance of bilateral ectodermal thickenings - nasal placodes on the ventrolateral aspect of the frontonasal prominence.
38
How are nasal pits formed?
Nasal placodes invaginate, the entrance to each pit is the future nostril. A horseshoe-shaped ring forms around the entrance to each nostril.
39
What is the oronasal membrane?
The thin sheet of cells separating the nasal pits and the stomodaeum.
40
What happens with the maxillary prominences in development?
They grow medially, pushing together the nasal prominences in the midline. They then fuse with medial nasal prominences, which themselves fuse in the midline.
41
What is the role of the palate?
Separation of the nasal and oral cavity.
42
What is the palate derived from?
Maxillary and medial nasal prominences.
43
What happens when the medial nasal prominences fuse at the midline?
The nostrils and mouth are separated and gives rise to the philtrum, median part of the maxillary bone, and the primary palate.
44
What makes up the secondary palate?
Each maxillary prominence has a palatal shelf that grows towards the midline and fuses with each other and the primary palate.
45
Why does the mandible need to grow large enough?
To allow the tongue to drop out of the way to allow fusion of the palatal shelves.
46
How does the nasal septum develop?
As a midline down-growth, it fuses with the palatal shelves.
47
What causes a cleft palate?
Failure of one or both palatal shelves to reach the midline and fuse with its counterpart.
48
What is a lateral cleft lip due to?
Failure of fusion of the medial nasal prominence with the maxillary prominence.
49
What is cleft lip and palate due to?
Combined failure of palatal shelves to meet in midline.
50
How is the lens of the eye developed?
In week 4, out-pockets of the forebrain grow to make contact with overlying ectoderm -> optic placodes -> lens of the eye.
51
Describe timings of the development of the eyelids.
At the end of the embryonic periods, week 8, they begin development, they then fuse together in second trimester and reopen in third.
52
How does the positioning of the eyes change through development?
Primordia of the eyes are on the side of the head but as facial prominence grow, they move to the front of the face.
53
Where do the ears develop from?
External auditory meatus develops from 1st pharyngeal cleft. | Auricles develop from within the 1st and 2nd pharyngeal arches.
54
Which ossicles develop from which pharyngeal arches?
1st arch - malleus and incus. | 2nd arch - stapes.
55
How are the auditory vesicles formed?
Otic placodes are ectoderm that thicken and then sink. They then invaginate to form vesicles.
56
How does the positioning of the ears change through development?
External ears develop in neck originally but as mandible grows, they ascend to the side of the head, in line with the eyes.
57
What is foetal alcohol syndrome?
Alcohol crosses the placenta so consumption during pregnancy affects development and causes classic facial symptoms: small eye/nose opening, thin philtrum, under-developed jaw.
58
What are the two components of the pituitary gland?
Anterior lobe and posterior lobe.
59
What makes up the anterior lobe of the pituitary gland?
Andenohypophysis, Rathke's pouch, ectoderm origin, endocrine function.
60
What makes up the posterior lobe of the pituitary gland?
Neurohypophysis, infundibulum, neuroectoderm origin, neuroendocrine function.
61
What is the posterior lobe of the pituitary gland derived from?
The developing brain, a down-growth from the diencephalon forms in the midline - infundibulum.
62
What is the pituitary stalk from?
A connection between the diencephalon and the infundibulum (forms floor of hypothalamus).
63
What is Rathke's pouch?
Out-pushing from the roof of the oral cavity growing up to meet the infundibulum.
64
What happens to Rathke's pouch?
It loses its connection with the roof of the mouth and comes to lie anterior to the infundibulum and wraps around the pituitary stalk, differentiates into the endocrine cells of the anterior pituitary.
65
How is the anterior lobe of the pituitary linked to the hypothalamus and posterior lobe functionally?
Hypophyseal portal system.
66
What can persistent remnants of Rathke's pouch form?
Cysts.
67
When does the tongue appear?
4th week.
68
What do the two lateral lingual swellings of the tongue develop from?
1st pharyngeal arch.
69
What do the three medial lingual swellings of the tongue develop from?
1st pharyngeal arch -> tuberculum impar. 2nd and 3rd arches -> cupola. 4th arch -> epiglottal swelling.
70
What happens to the lateral and medial swellings in development of the tongue?
The lateral lingual swellings grow over the tuberculum impar. The 3rd arch component of the cupola overgrows the 2nd arch component. Extensive degeneration occurs so the tongue is freed from the floor of the oral cavity except from lingual frenulum.
71
What is the sensory innervation of the tongue?
Anterior 2/3: lingual nerve (CN V3), nerve of 1st pharyngeal arch. Posterior 1/3: glossopharyngeal nerve (CN IX), nerve of 3rd pharyngeal arch.
72
What is the special sensory innervation of the tongue?
Anterior 2/3: chorda tympani (CN VII), nerve of 2nd pharyngeal arch, passes into 1st pharyngeal arch through middle ear. Posterior 1/3: glossopharyngeal nerve (CN IX), nerve of 3rd pharyngeal arch.
73
What is the motor innervation of the tongue?
Intrinsic and extrinsic muscles develop from myogenic precursors that migrate into developing tissue. Palatoglossus - vagus nerve (CN X). All other muscles - hypoglossal nerve (CN XII).
74
What is the first endocrine gland to develop?
The thyroid.
75
How does the thyroid first appear in development?
Floor of pharynx as an expansion of mesenchyme between tuberculum impar and cupola.
76
What is the final position of the thyroid?
Anterior neck.
77
What happens at the point of origin of the thyroid?
It bifurcates and descends as bilobed diverticulum, connected to the isthmus.
78
What connects the thyroid gland to the tongue in its descent?
Thyroglossal duct.
79
What are the cell types of the thyroid and the secretions?
Follicular cells - thyroxine and triidothyronine (T4/3), | Parafollicular cells - calcitonin.
80
What are follicular and parafollicular cells of the thyroid formed from?
Follicular - thyroid diverticulum. | Parafollicular - ultimobranchial body of the 4th pouch.
81
What is a thyroglossal cyst?
At any point along the migratory path of the thyroid gland, near or in the midline of the neck, remnants of the thyroglossal duct.
82
What is a thyroglossal fistula?
Thyroglossal cyst connected to the outside by a fistulous canal.
83
Where can ectopic thyroid tissue be found?
Anywhere along the path of descent of the thyroid gland, normally at the base of the tongue, just behind the foramen cecum.
84
What is first arch syndrome?
Spectrum of defects in development of the eyes, ears, mandible, and palate from failure of colonisation of the first arch with neural crest cells.
85
What is the presentation of first arch syndrome?
Treacher-Collins syndrome - inherited, autosomal dominant condition characterised by hypoplasia of the mandible and facial bones.
86
What is DiGeorge syndrome?
Congenital thymic aplasia and absence of parathyroid glands.
87
What is the cause of DiGeorge syndrome?
Deletion on chromosome 22.
88
What are the features of DiGeorge syndrome?
CATCH 22: cardiac abnormality, abnormal facies, thymic aplasia, cleft palate, hypocalcaemia/hypoparathyroidism and abnormality on chromosome 22.
89
What is CHARGE syndrome?
CHD7 heterozygous mutation, essential for production of multipotent neural crest cells.
90
What are the features of CHARGE syndrome?
Coloboma (hole in iris), heart defects, atresia, retardation of growth and development, genital hypoplasia, ear defects.

14. Head and Neck (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions