Lecture 50 Embryology of the Face Flashcards
Describe the five anatomical regions of the human face.
Forehead, eyes/orbit, nose/nasal complex, “cheeks”, and mouth
Which organisms have a face?
most vertebrates
What bone comprises a majority of the forehead?
frontal bone
Name the seven bones that form the orbital area.
Frontal, Maxillary, Zygomatic, Sphenoid, Ethmoid, Lacrimal, and Palatine
Two nasal bones, the frontal process of the maxilla (externally) and the ethmoid and superior concha (internally) form which anatomical region of the human face?
Nose and nasal complex
What bones form the “cheek” area?
largely, the maxillae and zygoma (laterally) and the mandible (inferiorly)
The mandible (lower jaw) and maxilla (upper jaw) form what anatomical region of the human face?
Mouth region
Describe the osteology of the human face.
Bones are formed via endochondral ossification (largely basicranial bones) and via intramembranous ossification (mostly facial and vault bones)
Major innervation of the face comprises sensory, mostly from CN _____ and motor from CN _____ and CN ____ for masticatory muscles.
V
VII
V
Name the six major facial muscles
Orbicularis oris, Orbicularis oculi, buccinators, platysma, fronto-occipitalis, zygomaticus major
Which two branchial arches are mostly concerned with the embryological formation of the face?
branchial arches 1 and 2
Name the five embryological facial prominences.
unpaired frontonasal prominence, paired maxillary prominences, paired mandibular prominences
What is the primordium of the mandible?
Meckel’s cartilage, which is replaced by membranous bone
What are the four functions of the human face?
Focal point for cranial senses, air intake, food intake, and crucial emotional signaling
The trigeminal nerve (CN V) via its three divisions (____, ____, and _____) carries the majority of ____ sensation from the face. The _____ (ventral rami ____, ____) carries sensation from the region of the angle of the jaw.
Opthalmic (V1), Maxillary (V2), Mandibular (V3)
GSA
Great auricular nerve
C2,C3
Muscles of the face are mostly innervated by SVE fibers in what nerve? What are the exceptions of this statement?
Facial Nerve (CN VII) The levator palpebrae superioris is innervated by CN III (GSE) and the masticatory muscles, including the mylohyoid and anterior belly of the digastric by SVE fibers of CN V
Name the role of the muscles of the face.
controlling orifices and apertures for communication
What is the primary function of of the orbicularis oculi and what nerve is it innervated by?
closes the eyes
CN VII
The five prominences appear around what structure and by when?
the prominences appear by early week four by mesenchymal proliferation and appear around the stomodeium (primitive mouth)
Name the derivatives of the frontonasal prominence.
formation of the nostrils/nose
What prominence will derive the maxilla, upper cheeks, upper lip, philtrum, and primary and secondary palates?
paired maxillary prominences
Name the derivatives of the paired mandibular prominences.
Lower cheek, lower lip, and mandible
Abnormal development of the primary and secondary palates can lead to what?
Cleft lip (CL), cleft palate (CP), or combinations (CLP)
Lip/palate development occurs sequentially, with lips first at ____ weeks and then primary palate by week _____ with secondary palate later at _____ weeks.
4-8
6
6-12
CLP, CP, and CL arise from failure of what processes to occur?
Failure of the medial or lateral nasal processes to fuse with the medial aspects of the maxillary processes and/or failure of the primary palate to fuse with aspects of the secondary palate and/or failure of the right and left portions of the secondary palate to close
The causes of Cl, CP, and CLP are described as what?
both syndromic and non-syndromic forms; causes are multifactorial and involve genetics, environmental factors, and teratogens
What are the physical effects of CL, CP, and CLP in children?
difficulty with eating and swallowing
vanity concerns
