Auricle

The auricle develops from six mesenchymal proliferations at the dorsal ends of the first and second pharyngeal arches, surrounding the first pharyngeal cleft (Fig. 16.10, A and E). These swellings (auricular hillocks), three on each side of the external meatus, later fuse and form the definitive auricle (Fig. 16.10,

Meckel's f Stylohyoid ligament

Meckel's

Mole Meatus

Hyoid bone

Incus Stapes f- Styloid process f Stylohyoid ligament

Malleus

Ligaments

^etrous bone

Perilymphatic

/space liiw' Wall of inner ear

Oval window Stapes

Tympanic cavity

Endodermal epithelium

Figure 16.9 A. Derivatives of the first three pharyngeal arches. Note the malleus and incus at the dorsal tip of the first arch and the stapes at that of the second arch. B. Middle ear showing the handle of the malleus in contact with the eardrum. The stapes will establish contact with the membrane in the oval window. The wall of the tympanic cavity is lined with endodermal epithelium.

Hyoid bone

Malleus

Ligaments

^etrous bone

Incus Stapes f- Styloid process

Hyoid Malleus Incus

Figure 16.9 A. Derivatives of the first three pharyngeal arches. Note the malleus and incus at the dorsal tip of the first arch and the stapes at that of the second arch. B. Middle ear showing the handle of the malleus in contact with the eardrum. The stapes will establish contact with the membrane in the oval window. The wall of the tympanic cavity is lined with endodermal epithelium.

Ectodermal epithelium

Ectodermal epithelium

B-D and G). As fusion of the auricular hillocks is complicated, developmental abnormalities of the auricle are common. Initially, the external ears are in the lower neck region (Fig. 16.10F), but with development of the mandible, they ascend to the side of the head at the level of the eyes.

Was this article helpful?

0 0
Emergency Panic Remedies

Emergency Panic Remedies

Eliminate Your Panic And Anxiety Attacks Instantly With These Proven Techniques! There’s
 very
 little
 in
 this 
world
 that 
is
 as 
frightening
 and
 uncomfortable
 as 
a panic
 attack. 

Once
 they
 start,
 panic
 attacks
 can
 send
 you
 spiraling
 out
 of control.

Get My Free Ebook


Responses

  • kaiju
    Where is the malleus incus and stapes?
    7 years ago

Post a comment