27 Head and Neck

Question 1

most of the head and face develop from WHAT

Answer 1

PHARYNGEAL APPARATUS which is a series of bulges and internal pouches that appear week 4

Question 2

bulges covered with ectoderm externally, endoderm internally, and filled with mesenchyme (mesoderm and neural crest)
eventually FIVE PAIRS develop
each has CAN: Cartilage Bar, Artery and Nerve

Answer 2

PHARYNGEAL ARCHES

Question 3

these are external grooves that separate each pharyngeal arch

Answer 3

PHARYNGEAL CLEFTS (GROOVES)

Question 4

these are INTERNAL ooutpocketings of the endoderm lined foregut (pharynx)

Answer 4

PHARYNGEAL POUCHES

Question 5

Skeletal elements found in arch 1 (I’M)

Answer 5

Maxilla, Mandible, Incus, Malleus

Question 6

Skeletal elements found in arch 2 (S)

Answer 6

Stapes, Styloid Process

Question 7

Skeletal elements found in arch 3 (H)

Answer 7

Hyoid (lower body) and Greater Horn

Question 8

Skeletal elements found in arch 4 (T)

Answer 8

Thyroid Cartilage

Question 9

a cranial nerve grows into each arch and INNERVATES what

Answer 9

mucosa and muscles that form them

Question 10

each arch is supplied by what artery

Answer 10

a SEPERATE artery

Question 11

outpocketings of the endoderm lined foregut (pharynx) give rise to the epithelial of auditory tube, middle ear, inner lining of tympanic membrane and the palatine tonsils

Answer 11

PHARYNGEAL Pouches

Question 12

Only CLEFT 1 gives rise to a permanent structure which is

Answer 12

EXTERNAL AUDITORY MEATUS and the outer lining of the tympanic membrane

Question 13

When do the other clefts disapper

Answer 13

when ARCH 2 OVERGROWS the other clefts leaving a small cervical sinus which is eventually lost

Question 14

If persistence of a cervical sinus occurs it can cause formation of what

Answer 14

a FISTULAR or CYST on the side of the neck

Question 15

Where does most of the glandular tissue of the thyroid orginiate from

Answer 15

MIDLINE GROWTH from the endoderm in the floor of the future pharynx

Question 16

primordial thyroid cells descends through the developing tongue at a small pit known as

Answer 16

FORAMEN CECUM

Question 17

Failure of the thyroid tissue to migrate results in what

Answer 17

LINGUAL THYROID GLAND

Question 18

remenants of the thyroglossal duct can result in what

Answer 18

CYST or FISTULA along the midline of the front of neck

Question 19

how does tongue development begin

Answer 19

swellings appear on the endoderm on the floor of the mouth (intially from arches 1-4) but eventually arch 2 is overgrown

Question 20

(Tongue Tie ) – the tip of the tongue is tethered to the floor of the mouth by a thick band of tissue “anchored tongue”

Answer 20

ANKYLOGLOSSIA

Question 21

when does salivary gland development begin and what do they initally form as

Answer 21

SOLID EPITHELIAL BUDS beginning in weeks 6 and 7
Parotid develops first from oral ectoderm
Submandibular and sublingual glands develop from endoderm lined portion of oral cavity

Question 22

The arches that make up the tongue are:
One arch is lost

Answer 22

Arches 1, 3 and 4
Arch 2 is LOSt

Question 23

Anterior 2/3rd of the tongue is made up of Arch __ innervated by __
Posterior 1/3 of the tongue is made of arch ___ innervated by
Epiglottis and way post tongue = Arch ___ innervated by ___

Answer 23

Arch 1 – CN 5 = Trigeminal Nerve
Arch 3 – CN 9 = Glossopharyngeal Nerve
Arch 4 – CN 10 = vagus nerve

Question 24

Development of face is made up of two parts

Answer 24

Frontonasal (FN) prominence : Medial and Lateral Nasal prominence
Pharyngeal Arch 1 : Maxillary and Mandibular Prominence (2 each)

Question 25

The maxillary prominences grow towards each other trapping:

Answer 25

stupid MEDIAL nasal prominences in the middle

Question 26

The upper lip is formed from which two prominences

Answer 26

MAXILLARY prominecnces and stupid medial nasal prominences

Question 27

The frontonasal prominence forms what at week 10

Answer 27

Forehead

Question 28

Medial Nasal and Lateral Prominences Form:

Answer 28

Medial – middle of nose and philtrum of upper lip
Lateral – sides of the nose

Question 29

The Mandibular prominences form

Answer 29

LOWER LIP and FACE

Question 30

How is the PALATE formed?

Answer 30

Maxillary prominences grow together from both sides, trapping the inside part of medial nasal prominences

Question 31

This palate forms when the inner portions of the two MEDIAL nasal prominences = INTERMAXILLARY segment merges together at the midline forming a cute triangle

Answer 31

PRIMARY PALATE

Question 32

This palate forms when the inner portions of the MAXILLARY prominences = PALATINE SHELVES grow together and fuse in the midline

Answer 32

SECONDARY PALATE

Question 33

What happens when the maxillary prominence fails to fuse with the medial nasal prominence
occurs during weeks 7-8

Answer 33

CLEFT LIP

Question 34

What happens when the maxillary prominence fails to fuse with the lateral nasal prominence
The nasolacrimal duct = exposed

Answer 34

OBLIQUE FACIAL CLEFT

Question 35

When the maxillary prominence fails to fuse with each other and or with the primary or anterior palate during weeks 8-10

Answer 35

CLEFT PALATE

Question 36

many craniofacial defects are due to abnormalities in the migration or proliferation of what cells in the phayngeal arches

Answer 36

Neural Crestrs

Question 37

In this syndrome, the infant has a small, underdeveloped mandible and cheek bones. External ears are malformed and hearing defects are common.
External features on eyes = abnormal and are described as downward slanting eyes

Answer 37

First Arch Syndrome – TREACHER COLLINS SYNDROME

Question 38

In this syndrome, the infant has a small, underdeveloped mandible. Tongue is posteriorly placed with a tendency to ball up at the back of the mouth and fall into throat
Experience feeding and breathing problems

Answer 38

First ARCH syndrome: PIERRE ROBIN SEQUENCE

Question 39

This defect has a complete or partial absence of thymus and parathyroid glands due to failure of third and fourth pharyngeal pouches to differntiate properly.

Answer 39

DIGEORGE ANOMALY