Superficial Face & Parotid Region Flashcards
What are the major bones of the anterior skull from inferior to superior?
Mandible (most inferior)
Maxilla
Zygomatic
Frontal (most superior)
What are the three foramina of the anterior skull, what passes through these, and how are the arranged?
Mental F. (Mental N. - V3)
Infraorbital F. (Infraorbital N. - V2)
Supraorbital F. (Supraorbital N. - V1)
Where are all of the muscles of facial expression derived from?
All 18 muscles of facial expression are derived from the 2nd Pharyngeal Arch, and are innervated by CN VII.
In general, where do the muscles of facial expression originate & insert?
The muscles of facial expression originate from either bone/fascia & insert into the skin of the face.
What is the muscle that wrinkles the scalp and is associated with the calvaria?
The OCCIPITOFRONTALIS is a muscle of the scalp and is composed of a frontal belly (FRONTALIS) responsible for wrinkling the skin of the forehead & contributes to the elevation of the eyebrows.
The other portion of this muscle is the occipital belly.
What are the three parts & functions of the muscle surrounding the orbit?
ORBICULARIS OCULI
Orbital - tightly constricts or contracts the skin around the eye (winking/squinting)
Palebral - gently closes the skin around the eye (blinking - palebral reflex)
Lacrimal - acts on lacrimal sac
What acts as the sphincter of the mouth and allows lips to pucker?
ORBICULARIS ORIS is the sphincter of the mouth, which functions to close, protrude, and pucker the lips & mouth.
It consists partly of fibers that insert into it from other facial muscles.
What three muscles elevates the upper lip or lowers the bottom lip?
LEVATOR LABII SUPERIORIS raises the upper lip.
DEPRESSOR LABII INFERIORIS lowers the bottom lip.
L.L.S. ALAEQUE NASI flares the nostrils and raises upper lip.
What three muscles are involved in smiling?
ZYGOMATIC MAJOR - originates on zygomatic bone
ZYGOMATIC MINOR
RISORIUS
All pulls corners of mouth superiorly & laterally
Which two muscles affect the angle of the mouth?
The LEVATOR/DEPRESSOR ANGULI ORIS raises the angle/lowers is inferolaterally.
What is the major muscle involved is involved in eating/drinking and playing a horn instrument?
The BUCCINATOR presses the cheek against the molar teeth, which keeps food out of the oral vestibule during mastication and is active when expelling air from the oral cavity.
What two muscles originate/insert at the pterygomandibular raphe?
The buccinator & superior constrictor muscles both attach to the pterygomandibular raphe.
What is the parotid fascia/capsule a continuation of and what does it cover?
The parotid fascia is a continuation of the cervical or deep investing fascia that covers the trapezius and SCM muscles in the neck.
It covers the parotid gland (& bed) and encapsulates the MASSETER muscle (so we think).
What is the parotid gland’s shape, location, and what is the isthmus?
The parotid gland is triangular and irregularly wedge shaped.
It is found in the parotid bed, and extends posteriorly between the ranks of the mandible (on its anterior side) and the mastoid process of the temporal bone (on its posterior side. This extension is called the isthmus.
What are the boundaries of the parotid bed?
Posteriorly - SCM’s anterior side & EAM
Anteriorly - posterior ½ of Masseter
Superiorly - Temporal Bone & Zygomatic Arch
Inferior - Submandibular Triangle
Explain the course of the parotid duct.
- Extends from the anterior border below the zygomatic bone
- Cross over masseter
- Goes deep at the anterior border of the buccal fat pad
- Opens in interior of mouth opposing the 2nd superior molar
Where is the lateral pharyngeal space located, and how does it communicate with the retropharyngeal space?
The LPS is the area deep to the parotid fascia and superficial to the buccopharyngeal fascia, and it communicates with the retropharyngeal space medially.
Explain the course of CN VII.
- Exits the cranium through the stylomastoid foramen
- Gives off branches to muscles (p. digastric & stylohyoid) and the posterior auricular branch.
- Peirces parotid gland and splits into superior (temporofacial) and inferior (cervicofacial) divisions.
4S. The temporofacial division gives off a temporal branch, zygomatic branch, and an anastomotic buccal branch.
4I. The cervicofacial division gives off an anastomotic buccal branches, a mandibular branch, and a cervical branch.
What is CN VII’s relationship to the blood vessels of the area?
CN VII (most superficial)
Retromandibular v.
External Carotid a. (most deep)
What is the sympathetic innervation of the parotid gland?
Sympathetic innervation of the parotid gland (shuts off salivation) is from the cervical chain ganglia (T1-T2), which is running with branches of the external carotid a. (most likely posterior auricular a.).
What is the GSA innervation of the parotid fascia & gland?
GSA innervation is mixed from cervical plexus (C2-C3) and from CN V3 (Mandibular n.)
What is the Mental N. a continuation of?
The inferior aveolar n. (V3) gives off the n. to mylohyoid before entering the mandibular foramen, then continues until the mental foramen where it exits and becomes the mental n. which provides GSA innervation to the lower face.
What are the four minor cutaneous nerves?
Supratrochlear n (V1)
Zygomaticofacial n. (V2)
Buccal n. (V3)
Auriculotemporal n. (V3)
Explain the path of the tympanic n. and its contribution to parasympathetic GVE innervation of the parotid gland
- After giving off GSA fibers to middle ear, the tympanic n. becomes the lesser petrosal n. (preganglionic GVE-fibers only)
- Lesser petrosal n. exits the bone via LP hiatus, then runs across the middle cranial fossa to the foramen ovale.
- Follows V3 fibers through foramen ovale
- Synapses with postganglionic nerves in otic ganglia (located outside of cranium, medial to V3 fibers)
- Postganglionic GVE fibers distribute via the auriculotemporal branch of V3.
