RA 2 Ear Flashcards
Organ of hearing consisting of the external ear, middle ear, and internal ear
Ear (Pinna):
Ear (Pinna):
- No 2 ears are identical…
- Not even those on the same individual
- One ear sits higher than the other one
- The ears change less in a lifetime than any other facial feature
- The ear is formed like a “wedge” not flat, can put pencil between ear & head
- the ear is made of cartilage, except the lobe (fatty connective tissue)
Antomical Structures of the Temporal Bone used for locating the Modeled Ear
- External Auditory Meatus
- Zygomatic Arch
- Mandibular Fossa
- Mastoid Process
(Ear Passage, Orifice)
External Auditory Meatus
(on temporal bone, divides length of ear in two parts)
Zygomatic Arch
(cavity under temporal bone, in front of ear passage, socket form/hinge of mandible)
Mandibular Fossa
(inverted, inferior of temporal bone, behind/below ear passage)
Mastoid Process
Internal Ear Bones
Note: have No Effect on surface form & Not useful as anatomical guide
- Malleus (hammer)
- Incus (anvil)
- Stapes (stirrup)
Hollows or Cavities
a. Ear Passage
b. Concha (shell)
c. Triangular Fossa
d. Scapha
e. Intertragic Notch
hole located in inferior portion of the medial 1/3 of ear, anterior border, orifice leading into organ of hearing, not visible from front or direct profile view.
Ear Passage:
(concave shell): 1st deepest depression of the ear located superior and posterior to the ear passage, vertical dimensions partially divided into 2 sections by a Crus or leg of Helix of ear, walled in on all slides by the bordering parts of the ear that affects size of Concha
Concha
2nd deepest depression of ear between the Crura (superior crus and anterior crus), triangular in form
Triangular Fossa:
fossa between inner rim (antihelix) & outer rim (helix) of the ear, shallowest depression of ear, it’s length width & depth all vary among individual
Scapha:
opening/notch between Tragus & Antitragus of ear, spillway of the ear
Intertragic Notch:
Elevations or Ridges
a. Helix & Crus
b. Antihelix & Crura of Antihelix
c. Tragus
d. Antitragus
e. Lobe
outer rim of ear, general shape of question mark (?),begins superior to the lobe & ends by attaching to the cheek. Anterior portion merges with the faces at the temporal, superior portion separates from the temporal & side of the head (space to place pencil behind ear)
Helix
beginning/orgin of Helix (outer rim) that is flattened and ends in the Choncha. Orgin is the Anterior/Middle/Posterior (divide it) area of the Concha
Crus:
inner rim of ear, starts at superior border of the lobe & continues upward until it ends by becoming the Crura. Forms the superior & posterior walls of the concha.
Antihelix
superior & anterior bifurcation of the antihelix; made up of 2 parts:
Crura
- Superior Crus
- Anterior Crus
elevation protecting the ear passage; arises from the posterior margin of the lateral cheek; project both posteriorly & laterally
Tragus
small eminence obliquely opposite the tragus; located on the superior border of the lobe of the ear; helps form intertragic notch
Antitragus
inferior fatty 1/3 of ear (soft & non-cartlidge); most inferior part of ear; anteriorly attaches to cheek & part of intertragic notch; superiorly attaches to intertragic notch, antitragus, antihelix, & helix
Lobe
Inclination of the Ear: use the anterior margin as a guide
If you have to attach ear, know location & inclination. Assume line form by attachment of ear at the temporal, tragus & lobe; draw a line at these 3 points
Parallel/matches to assume line; if look at bony profile look at line from glabella to maxilla & on facial profile, medium line from brow to medium line of upper lip (general guidelines without photo)
In terms of forming ear keep in mind the projection (its not flat), intrigue (ridges & hollow of ear), where place it on head & what guides can you use to place it & angle you would incline the ear.
