#EXTERNAL ACOUSTIC MEATUS SKIN#

The auriculotemporal branch of the mandibular nerve (CN V3) with the nerve to external acoustic meatus supplies the anterior and superior wall of the canal with sensory innervation. The sensory innervation of the external auditory meatus is provided by branches of several cranial nerves. The lymph from the external acoustic meatus is drained into the superficial and deep cervical lymph nodes. Venous drainage happens through the superficial temporal vein, the external jugular vein, and the pterygoid plexus. The anterior part of the external acoustic meatus is supplied by the superficial temporal artery, while the posterior part of the ear canal is supplied by the posterior auricular artery. Vasculature and innervation of the external acoustic meatus Arterial supply and venous drainage

#EXTERNAL ACOUSTIC MEATUS SKIN#

The main function of the earwax is to protect the skin of the canal, take part in cleaning and lubrication, as well as provide protection against water, bacteria, and fungi.

The main components of the earwax are shed layers of skin, hair, long-chain fatty acids, cholesterol, and squalene. Sebaceous glands produce viscous secrete, while the apocrine glands produce less viscous secrete. It is created by two different glands - sebaceous and apocrine sweat glands. Cerumen is produced in the cartilaginous part of the canal. Medically known as cerumen, in a common language known as earwax, is a brown, yellowish, gray substance that is secreted in the external acoustic canal. Within the canal are glands responsible for the production of the wax. The canal is lined with skin that has rarely located hairs. The cartilage of the external acoustic meatus together with the cartilage of the auricle forms a groove that opens superiorly and posteriorly. This action will help to align the lateral and medial parts. In order to gain better visualization, the auricle has to be pulled backward, upwards, and slightly lateral. The lateral part of the external acoustic canal is directed posteriorly and superiorly, but the middle part is directed anteriorly and inferiorly.ĭuring the ear examination, these directions are important to know for better visualization of the tympanic membrane. Anatomically the posterior wall is related to the mastoid cells from the mastoid process, meanwhile the anterior and inferior walls - to the temporomandibular joint.

The anterior and inferior walls of the bony part are built by the tympanic part of the temporal bone, while the posterior and superior walls - by the squamous part of the temporal bone. In contrast, the inner and posterior walls of the canal are fibrous and lie within the temporal bone, forming the bony part. The outer or lateral third of the external auditory canal is the cartilaginous part. The external acoustic meatus is a partly cartilaginous and partly bony S-shaped canal, about 2.5-3.5 cm in length with a diameter of about 9 mm, leading to the tympanic membrane, which separates the external ear from the middle ear. The external acoustic meatus conducts sound waves to the tympanic membrane. The external acoustic meatus (also external auditory canal, external auditory meatus or ear canal, Latin: meatus acusticus externus) is an air-filled tubular space that extends from the auricle of the external ear into the temporal bone to the tympanic membrane.

External acoustic meatus