The lungs are the most important organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. The pleurae, which are thin, smooth, and moist, serve to reduce friction between the lungs and chest wall during breathing, allowing for easy and effortless movements of the lungs.
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 the air to vibration in cochlear fluid. The malleus bone bridges the gap between the eardrum and the other ossicles.
In anatomy, the temporomandibular joints (TMJ) are the two joints connecting the jawbone to the skull. It is a bilateral synovial articulation between the temporal bone of the skull above and the mandible below; it is from these bones that its name is derived. This joint is unique in that it is a bilateral joint that functions as one unit. Since the TMJ is connected to the mandible, the right and left joints must function together and therefore are not independent of each other.
The vestibulocochlear nerve or auditory vestibular nerve, also known as the eighth cranial nerve, cranial nerve VIII, or simply CN VIII, is a cranial nerve that transmits sound and equilibrium (balance) information from the inner ear to the brain. Through olivocochlear fibers, it also transmits motor and modulatory information from the superior olivary complex in the brainstem to the cochlea.
The glossopharyngeal nerve, also known as the ninth cranial nerve, cranial nerve IX, or simply CN IX, is a cranial nerve that exits the brainstem from the sides of the upper medulla, just anterior to the vagus nerve. Being a mixed nerve (sensorimotor), it carries afferent sensory and efferent motor information. The motor division of the glossopharyngeal nerve is derived from the basal plate of the embryonic medulla oblongata, whereas the sensory division originates from the cranial neural crest.
An ear is the organ that enables hearing and body balance using the vestibular system. In mammals, the ear is usually described as having three parts: the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most animals, the word "ear" often refers to the external part alone. The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing. The ear is a self cleaning organ through its relationship with earwax and the ear canals. The ears of vertebrates are placed somewhat symmetrically on either side of the head, an arrangement that aids sound localization.
The auriculotemporal nerve is a sensory branch of the mandibular nerve (CN V3) that runs with the superficial temporal artery and vein, and provides sensory innervation to parts of the external ear, scalp, and temporomandibular joint. The nerve also conveys post-ganglionic parasympathetic fibres from the otic ganglion to the parotid gland.
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 tensor veli palatini muscle is a thin, triangular muscle of the head that tenses the soft palate and opens the Eustachian tube to equalise pressure in the middle ear.
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 posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles and it has openings for blood vessels. From its borders, the mastoid part articulates with two other bones.
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.
The deep auricular artery is a branch of the maxillary artery. The deep auricular artery pierces the external acoustic meatus. It provides arterial supply to the skin of the external acoustic meatus, and contributes arterial supply to the tympanic membrane, and the temporomandibular joint.
The infratemporal fossa is an irregularly shaped cavity that is a part of the skull. It is situated below and medial to the zygomatic arch. It is not fully enclosed by bone in all directions. It contains superficial muscles, including the lower part of the temporalis muscle, the lateral pterygoid muscle, and the medial pterygoid muscle. It also contains important blood vessels such as the middle meningeal artery, the pterygoid plexus, and the retromandibular vein, and nerves such as the mandibular nerve (CN V3) and its branches.
The mandibular fossa, also known as the glenoid fossa in some dental literature, is the depression in the temporal bone that articulates with the mandible.
The petrotympanic fissure is a fissure in the temporal bone that runs from the temporomandibular joint to the tympanic cavity.
The tela choroidea is a region of meningeal pia mater that adheres to the underlying ependyma, and gives rise to the choroid plexus in each of the brain’s four ventricles. Tela is Latin for woven and is used to describe a web-like membrane or layer. The tela choroidea is a very thin part of the loose connective tissue of pia mater overlying and closely adhering to the ependyma. It has a rich blood supply. The ependyma and vascular pia mater – the tela choroidea, form regions of minute projections known as a choroid plexus that projects into each ventricle. The choroid plexus produces most of the cerebrospinal fluid of the central nervous system that circulates through the ventricles of the brain, the central canal of the spinal cord, and the subarachnoid space. The tela choroidea in the ventricles forms from different parts of the roof plate in the development of the embryo.
The anterior perforated substance is a part of the brain. It is bilateral. It is irregular and quadrilateral. It lies in front of the optic tract and behind the olfactory trigone.
The caroticotympanic artery is a small, sometimes doubled artery which arises from the internal carotid artery. It leaves the carotid canal through a foramen to reach the tympanic cavity. It contributes arterial supply to the osseous part of the pharyngotympanic tube.
The articular disk of the temporomandibular joint is a thin, oval plate made of non-vascular fibrous connective tissue located between the mandible's condyloid process and the cranium's mandibular fossa.
