Head & Neck I Flashcards Preview

Term I: Embryology > Head & Neck I > Flashcards

Flashcards in Head & Neck I Deck (28):
1

When do pharyngeal pouches form? How many?

4th-5th weeks of dev

5 pouches

2

What structure gives off an arterial branch to each pharyngeal pouch as it forms? What are these branches called? Which branch never completely forms?

Aortic sac

Branches are called aortic arches

V never forms

3

Name adult structure of the following:

1st aortic arch
2nd aortic arch
3rd aortic arch

1st - maxillary artery
2nd - hyoid and stapedial arteries
3rd - common and proximal internal carotid arteries

4

What 4 embryological structures form the mesenchyme for formation of the head & neck?

1. Paraxial mesoderm
2. Lateral plate mesoderm
3. Neural crest
4. Ectodermal placodes

5

Otic placodes

Otic vesicles, origin of ear and vestibular structures

6

Lens placodes

Lens of the eye

7

Paraxial mesoderm

1. Floor of brain case
2. Small portion of occipital region
3. Voluntary muscles of craniofacial region
4. Dermis and connective tissue of dorsal head
5. Meninges caudal to prosencephalon

8

Lateral plate mesoderm

Laryngeal cartilages, connective tissue in region of laryngeal cartilages

9

1st pharyngeal arch: bones
(dorsal portion, ventral portion)

Dorsal = maxillary: maxilla, zygomatic bones, part of temporal bone

Ventral = mandibular: mandible and bones of middle ear (malleus and incus)

10

1st pharyngeal arch: muscles

Muscles - mastication (temporalis, masseter, pterygoids), ant belly of digastric, mylohyoid, tensor tympani and tensor palatini

11

1st pharyngeal arch: nerve

Trigeminal (CN V)

12

2nd pharyngeal arch: bones

stapes, styloid process of temporal bone, lesser horn and upper part of body of hyoid

13

2nd pharyngeal arch: muscles

stapedius, stylohyoid, post. belly of digastric, auricular, muscles of facial expression

14

2nd pharyngeal arch: nerve

Facial (CN VII)

15

3rd pharyngeal arch: bones

lower part of hyoid

16

3rd pharyngeal arch: muscles

stylopharyngeus

17

3rd pharyngeal arch: nerve

Glossopharyngeal (IX)

18

4th pharyngeal arch: muscles

Cricothyroid, levator palatini, constrictors of pharynx

19

4th pharyngeal arch: nerve

superior laryngeal branch of vagus

20

6th pharyngeal arch: nerve

recurrent laryngeal branch of vagus

21

Origin of thyroid, cricoid, cartilages of larynx

4th and 6th pharyngeal arches

22

1st pharyngeal pouch

middle ear cavity, eustachian tube

23

2nd pharyngeal pouch

Tonsillar fossa, NOT lymphatic tissue

24

3rd pharyngeal pouch: dorsal wing, ventral wing

Dorsal: inferior parathyroid

Ventral: thymus

25

4th pharyngeal pouch: dorsal wing, ventral wing

Dorsal: superior parathyroid

Ventral: ultimobranchial body (infiltrates thyroid as parafollicular or "C" cells to secrete calcitonin)

26

1st pharyngeal cleft

Ext. auditory canal

27

2nd-4th pharyngeal clefts

NOTHING

28

Which branchial cleft sinus is the most common? Where is the orifice?

2nd - orifice on ant. border of SCM, travels through carotid bifurcation to tonsillar fossa