Development

Question 0

In which week does the neural tube form?

Answer 0

3

Question 1

Where does the pharynx extend from and to?

Answer 1

Base of skull to inferior border of cricoid cartilage of the larynx

Question 2

Where are the oropharyngeal, nasal and the laryngeal parts of the pharynx?

Answer 2

Nasal - superior to soft palate Oropharynx - soft palate to larynx Laryngeal pharynx - posterior to larynx

Question 3

What are the pharyngeal arches?

Answer 3

System of mesenchymal proliferations in the neck region of the embryo

Question 4

How many arches are there in total and how are they numbered?

Answer 4

5 1, 2, 3, 4, 6

Question 5

What is each arch associated with?

Answer 5

A nerve, artery and cartilage bar

Question 6

What does the mesoderm of the pharyngeal arches give rise to?

Answer 6

Muscle, cartilaginous structures, CVS components

Question 7

What does the ectoderm of the pharyngeal arch give rise to?

Answer 7

Epidermis of skin

Question 8

How does the neural tube form?

Answer 8

Notochord signals overlying ectoderm to thicken to give a slipper shaped neural plate Edges elevate out of the plane of the disk and curl towards each other creating the neural tube

Question 9

Which part of the neural tube forms the brain and what three sections can it be divided into?

Answer 9

The anterior part

Prosencephalon - forebrain

Mesencephalon - midbrain

Rhombencephalon- hindbrain

Question 10

Where are most of the cranial nerves derived from and which are the exceptions?

Answer 10

Mid or hind brain I and II

Question 11

What groups can the cranial nerves be classified into?

Answer 11

Somatic efferent

Special sensory

Nerves of pharyngeal arches

Question 12

Which cranial nerves have mixed sensory and motor functions and supply the derivatives of the pharyngeal arches?

Answer 12

V - trigeminal

VII - facial

X - vagus

Question 13

Which cranial nerves have a relationship with the pharyngeal arch system?

Answer 13

Accessory (XI) Hypoglossal (XII)

Question 14

What is the facial skeleton derived from?

Answer 14

The frontonasal prominence

First pharyngeal arch

Question 15

Which pharyngeal arch are the muscles of facial expression derived from and therefore which nerve are they innervated by?

Answer 15

2

Facial nerve

Question 16

Which pharyngeal arch are the muscles of mastication derived from and therefore which cranial nerve are they innervated by?

Answer 16

1 Trigeminal nerve (V) branch - the mandibular nerve

Question 17

Which muscles does the third pharyngeal arch give rise to?

Answer 17

Stylopharyngeus

Question 18

Which muscles does the 4th pharyngeal arch give rise to?

Answer 18

Cricothyroid Levator palatini Constrictors of the pharynx

Question 19

Which muscles does the sixth pharyngeal arch give rise to?

Answer 19

Intrinsic muscles of the larynx

Question 20

Which is the nerve of the first pharyngeal arch?

Answer 20

Trigeminal nerve (V)

Question 21

Function of the trigeminal nerve?

Answer 21

Mixed

Principal sensory nerve of the head - skin and inside of mouth and nose

Motor: muscles of mastication, muscles derived from mandibular process

Question 22

Which is the nerve of the second pharyngeal arch?

Answer 22

Facial (VII)

Question 23

Function of the facial nerve?

Answer 23

Mixed Motor - muscles of facial expression and muscles from second pharyngeal arch Sensory - anterior two thirds of the tongue

Question 24

Nerve of the third pharyngeal arch?

Answer 24

Glossopharyngeal (IX)

Question 25

Function of the glossopharyngeal nerve?

Answer 25

Stylopharyngeus muscle Sensory - posterior third of the tongue

Question 26

Nerve of the fourth and sixth pharyngeal arches?

Answer 26

Vagus nerve (X) -4th arch branch is the superior laryngeal nerve -6th arch branch is the recurrent laryngeal nerve

Question 27

What are the neural crest-derived cartilage bars of each of the pharyngeal arches?

Answer 27

1 = Meckel's 2 = Reichert's 4+6 = cartilages of the larynx

Question 28

What can the first pharyngeal arch be divided into?

Answer 28

Maxillary and mandibular prominences

Question 29

What does Meckel's cartilage go onto form?

Answer 29

Malleus and incus of the ear Template for mandible which forms by membranous ossification

Question 30

What does Reichert's cartilage go onto form?

Answer 30

Stapes in middle ear Styloid process Hyoid bone (part of it)

Question 31

What does the cartilage of the third pharyngeal arch form?

Answer 31

Remainder of the hyoid bone

Question 32

What do the cartilages of the 4th and 6th pharyngeal arches go onto form?

Answer 32

Epiglottis Thyroid, arytenoid, cricoid cartilages

Question 33

Which artery is derived from each of the aortic arches?

Answer 33

1st and 2nd arch arteries disappear 3rd - internal carotid 4th - arch of aorta (L) and brachiocephalic trunk (R) 6th - pulmonary arch

Question 34

Where do the aortic arches come from?

Answer 34

The aortic sac which lies in the floor of the pharynx

Question 35

How many pharyngeal pouches are there?

Answer 35

4 pairs

Question 36

Which part of the pharyngeal pouches give rise to organs?

Answer 36

The epithelial endodermal lining

Question 37

What does pouch 1 give rise to?

Answer 37

Middle ear cavity Eustachian tube Lining of tympanic cavity Tympanic membrane (ear drum)

Question 38

What does pouch 2 give rise to?

Answer 38

Palatine tonsils Invaded by lymphoid tissue in third and fifth months

Question 39

What does pouch three give rise to?

Answer 39

Inferior parathyroid Thymus

Question 40

What does pouch four give rise to?

Answer 40

Superior parathyroid

Question 41

Which pouch is the parathyroid gland derived from?

Answer 41

3rd and 4th

Question 42

How many pharyngeal clefts are there?

Answer 42

4, but only one contributes to a definitive structure

Question 43

What is formed from the pharyngeal clefts? How?

Answer 43

External auditory meatus and part of the eardrum Dorsal part of the first cleft penetrates underlying mesenchyme and becomes the above

Question 44

How are the clefts obliterated?

Answer 44

Second pharyngeal ARCH proliferates and covers third and fourth arches. Merges with the epicardial ridge in the lower part of the neck. Obliterates the other clefts

Question 45

What can happen if the clefts are not obliterated?

Answer 45

Can have cysts or fistulae anywhere along the anterior border of the SCM