head and neck development

Question 1

jaws developed from?

Answer 1

the first branchial arch cartilage of the viscerocranium

Question 2

pharyngeal aka

Answer 2

brachial

Question 3

brachial also means

Answer 3

pharyngeal

Question 4

when do we see bilateral phayrngeal (brachial) apparatus begin to develop and how

Answer 4

pharyngeal apparatus begins to develop around 4-5 weeks post-fertilization and we see a recognizable body shape that is created by FOLDING

Question 5

what forms outer surface of the embryo

Answer 5

ectoderm (epithelium)

Question 6

what forms into a long tube incorporated into the body

Answer 6

endoderm (epithelium)

Question 7

what does the mesoderm (para-axial and lateral plate) separate?

Answer 7

separates the inner and outer surface

Question 8

what forms the gut tube

Answer 8

endoderm

Question 9

three divisions of primordial gut tube

Answer 9

foregut
midgut
hindgut

Question 10

foregut subdivisions and their contribution

Answer 10

pharyngeal foregut is to the respiratory diverticulum

foregut proper- up until bile duct and first part of the duedenum

Question 11

nerves of pharyngeal arches

Answer 11

V, VII, IX, ans X

Question 12

meckels cartilage

Answer 12

cartilage component of the mandible and associated with the first pharyngeal arch - it is formed by endochondrial ossification and gives ride to the incus and malleus

its perichondrium (2 layer of CT) gives rise to the sphenomandibular ligament and the anterior ligament of the malleus

Question 13

does meckels cartilage (mandibular cartilage) give rise to the development of the mandible bone

Answer 13

NO - it is just the cartilage plate associated with the mandibular prominence of the first pharyngeal arch

Question 14

cartilage assocaited with the second pharyngeal arch

Answer 14

reichart’s cartilage

Question 15

what does reichart’s cartilage give rise to?

Answer 15

stapes
styloid process
stylohyoid ligament
lesser horn and upper body of the hyoid bone

Question 16

muscles associated with the second pharyngeal arch

Answer 16

muscles of facial expression
stapedius
stylohyoid
posterior belly of the digastric

Question 17

cartilage component of the third pharyngeal arch and muscle, what innervates it?

Answer 17

lesser body and upper horn of the hyoid bone

stylopharyngeus is only muscle and is innervated by CN IX - the glossopharyngeal nerve

Question 18

T/F the laryngeal cartialges never ossify

Answer 18

TRUE - they do NOT ossify

Question 19

muscles of arch four and six

Answer 19

muscles of soft palate
muscles of the pharynx
intrinsic muscles of larynx

Question 20

pharyngeal cleft in adult

Answer 20

from the first pharyngeal cleft and the ectoderm (epithelium) will be the lining of the external auditory meatus

Question 21

pharyngeal membrane remnant

Answer 21

only remnant of pharyngeal membrane that exists in adult is the tympanic membrane

Question 22

pharyngeal pouch 1 contribution

Answer 22

tympanic ear cavity

auditory tube

Question 23

pharyngeal pouch 2

Answer 23

palatine tonsil

Question 24

pharyngeal pouch 3

Answer 24

dorsal - infererior parathyroid glands

ventral - stromal of thymus-

Question 25

pharyngeal pouch 4

Answer 25

dorsal - superior parathyroid glands

ventral - ultimobrachial body

Question 26

tongue development starts when and arises from what

Answer 26

week four and due to proliferation of endoderm and mesenchyme of the pharyngeal floor