The outer ear, external ear, or auris externa is the external portion of the ear, which consists of the auricle and the ear canal . It gathers sound energy and focuses it on the eardrum.
Cholesteatoma is a destructive and expanding growth consisting of keratinizing squamous epithelium in the middle ear and/or mastoid process. Cholesteatomas are not cancerous as the name may suggest, but can cause significant problems because of their erosive and expansile properties. This can result in the destruction of the bones of the middle ear (ossicles), as well as growth through the base of the skull into the brain. They often become infected and can result in chronically draining ears. Treatment almost always consists of surgical removal.
In the anatomy of humans and various other tetrapods, the eardrum, also called the tympanic membrane or myringa, is a thin, cone-shaped membrane that separates the external ear from the middle ear. Its function is to transmit sound from the air to the ossicles inside the middle ear, and then to the oval window in the fluid-filled cochlea. Hence, it ultimately converts and amplifies vibration in air to vibration in fluid. The malleus bone bridges the gap between the eardrum and the other ossicles.
The facial nerve is the seventh cranial nerve, or simply CN VII. It emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerves typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI and anterior to cranial nerve VIII.
The occipital bone is a cranial dermal bone and the main bone of the occiput. It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cerebrum. At the base of skull in the occipital bone, there is a large oval opening called the foramen magnum, which allows the passage of the spinal cord.
The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex.
Otoplasty denotes the surgical and non-surgical procedures for correcting the deformities and defects of the pinna, and for reconstructing a defective, or deformed, or absent external ear, consequent to congenital conditions and trauma. The otoplastic surgeon corrects the defect or deformity by creating an external ear that is of natural proportions, contour, and appearance, usually achieved by the reshaping, the moving, and the augmenting of the cartilaginous support framework of the pinna. Moreover, the occurrence of congenital ear deformities occasionally overlaps with other medical conditions.
The mastoid antrum is an air space in the petrous portion of the temporal bone, communicating posteriorly with the mastoid cells and anteriorly with the epitympanic recess of the middle ear via the aditus to mastoid antrum. These air spaces function as sound receptors, provide voice resonance, act as acoustic insulation and dissipation, provide protection from physical damage and reduce the mass of the cranium.
The roof is formed by the tegmen antri which is a continuation of the tegmen tympani and separates it from the middle cranial fossa.
The lateral wall of the antrum is formed by a plate of bone which is an average of 1.5 cm in adults.
The mastoid air cell system is a major contributor to middle ear inflammatory diseases.
The tympanic cavity is a small cavity surrounding the bones of the middle ear. Within it sit the ossicles, three small bones that transmit vibrations used in the detection of sound.
The asterion is the point on the skull corresponding to the posterior end of the parietomastoid suture.
The squamous part of temporal bone, or temporal squama, forms the front and upper part of the temporal bone, and is scale-like, thin, and translucent.
The mastoid part of the temporal bone is the back part of the temporal bone. Its rough surface gives attachment to various muscles and it has openings for the transmission of blood vessels. From its borders the mastoid part articulates with two other bones.
The petrous part of the temporal bone is pyramid-shaped and is wedged in at the base of the skull between the sphenoid and occipital bones. Directed medially, forward, and a little upward, it presents a base, an apex, three surfaces, and three angles, and houses in its interior, the components of the inner ear. The petrous portion is among the most basal elements of the skull and forms part of the endocranium. Petrous comes from the Latin word petrosus, meaning "stone-like, hard". It is one of the densest bones in the body.
The tympanic part of the temporal bone is a curved plate of bone lying below the squamous part of the temporal bone, in front of the mastoid process, and surrounding the external part of the ear canal.
In human anatomy, Prussak's Space is the small middle ear recess, bordered laterally by the flaccid part of Shrapnell's membrane, superiorly by the scutum and lateral malleal ligament, inferiorly by the lateral process of the malleus, and medially by the neck of the malleus. From the neck of the malleus, the anterior malleolar fold and the anterior ligament arise, demarcating Prussak's space anteriorly. Ventilation of Prussak's space is only possible posteriorly above the posterior malleus fold.
The mastoid lymph nodes are a small group of lymph nodes, usually two in number, located just beneath the ear, on the mastoid insertion of the sternocleidomastoideus muscle, beneath the posterior auricular muscle.
The following outline is provided as an overview of and topical guide to human anatomy:
A mastoidectomy is a procedure performed to remove the mastoid air cells. This can be done as part of treatment for mastoiditis, chronic suppurative otitis media or cholesteatoma. In addition, it is sometimes performed as part of other procedures or for access to the middle ear.
There are classically 5 different types of mastoidectomy:
Myringoplasty is the closure of the perforation of pars tensa of the tympanic membrane. When myringoplasty is combined with ossicular reconstruction, it is called tympanoplasty. The operation is performed with the patient supine and face turned to one side. The graft material most commonly used for the surgery is temporalis fascia. The tragal cartilage and tragal perichondrium are also used as the graft by some surgeons.
The ligaments of malleus are three ligaments that attach the malleus in the middle ear. They are the anterior, lateral and superior ligaments.
