Development of Face and Palate 3-4 Flashcards
(29 cards)
development of oropharynx
oropharynx is composed of the primitive oral cavity and the area of the foregut called pharynx
-oral pit (stomodeum) first appears in the 4th week, when the neural plate bends ventrally as neural folds develop to form forebrain
-oral pocket develops between forebrain
-heart will become oral cavity
-oral pit develops into maxillary process to upper/lower jaw
Grooves called pharyngeal pouches separate each arch within the pharynx. What is all 5?
- developing auditory tube
- palatine tonsil
- inferior parathyroids and thymus
- superior parathyroids
- ultimobranchial body
Pharyngeal arches bend around the pharynx as bars of tissue. What is all 5?
- mandibular: muscles of mastication, nerves, and blood supplu
- hyoid: facial muscles, vessels, and hyoid bone
3/4/5.
Vascular development
1-2 vessels develop in 4th and disappear in 5th week
3rd vessels take over facial area of first two
4-5th vessels arise, fourth becomes prominent and fifth disappears
6th vessels appear and become dominant along 3rd and 4th
3,4,6 stay
what are the arch vessels that stay?
3rd- common carotid arteries supply neck, face, brain
4th- dorsal aorta supply rest of body
6th- supply lungs with pulmonary circulation
internal carotid artery vs external
at first internal carotid artery supplies to face; external to brain
BUT, after 7 weeks it switches
internal carotid artery supplies blood to brain; external supplies blood to face
Muscle cells become apparent in which arch and what week?
first arch and fifth week
muscles of mastication are
temporalis, masseter, pterygoid
nerves develop with muscle
by the end of the 7th week, fibers of the fifth (1st arch) have entered the mandibular muscle mass, and 7th (second arch) cranial nerve have entered the facial muscle mass
1st arch make trigeminal nerve
2nd arch makes facial nerve
what does each arch make for nerves
1st arch make trigeminal nerve (mandibular) V
2nd arch makes facial nerve VII
3rd arch makes glossopharyngeal nerve IX
4th arch makes vagus X
the tongue relates to branches of…
-9th cranial nerve, which carries taste from the taste bud located in posterior 1/3 of the tongue
-7th cranial nerve, which carries taste from the taste buds on the anterior 2/3 of the tongue
-5th cranial nerve, which is the sensory nerve for the anterior 2/3 of the tongue
Cartilaginous skeletal Development I
Meckel’s cartilages appear bilaterally in the 1st arch
body of mandible forms after it
malleus and incus come from 1st arch
stapes come from 2nd
Cartilaginous skeletal Development II
Reichert’s cartilage come from second arch
-stapes, styloid process, lesser horn, and upper body of the hyoid
Cartilages of Face
-nasal capsule (ethmoid), sphenoid, auditory capsules, and basioccipital cartilages
cartilages
hard tissues that turn to bone
bones of face
frontal, parietal, squamous portions of temporal, and interoccipital cover skull
premaxillary, maxillary, zygomatic, and temporal cover face
sutures of face
2 bones meet
zygomaticomaxillary, frontomaxillary, zygomaticotemporal
syndesmosis= band of connective tissue
synchondrosis= band of cartilage
types of sutures
simple- straight line
serrated- zigzagging
squamosal- overlapping
4th week
-frontal process, oral pit, maxillary process, mandibular arch, hyoid arch
5th week
-nasal placodes
-frontal process is now called frontonasal
-eyes on side
6th
-face expand lateral
-eyes and maxillary process come to front
-philtrum
-auricular hillocks
7th week
-eyes and nose same plane
-ears
-upper lip fused
platal processes
-palate separates oral and nasal cavities
8th week
-posterior shelves push together forcing tongue forward and down
