The organs of the head are vital for the human body, and work together to provide us with senses of hearing, smell, sight, and even taste. These organs include the ear, the eye, the nose and sinuses, the salivary glands, and the oral cavity.
The ear can be divided into three sections: the external ear, the middle ear, and the inner ear. The external ear serves to capture and direct sound waves from the external acoustic meatus. This leads to the tympanic membrane, which separates the external ear from the middle ear. The middle ear is designed to transmit vibrations from the tympanic membrane to the inner ear via auditory ossicles (bones of the middle ear). The auditory ossicles, comprised of the malleus, incus and stapes, convert the sound vibrations reaching the tympanic membrane into energy that is then transmitted to the inner ear through the oval window.
The eye is a vital organ responsible for vision. Located within the bony orbit, it allows light to enter through the pupil. The size of the pupil is regulated by the ciliary muscles. Special photoreceptors, known as rods and cones, detect light passing through the eye and reaching the retina (a specialised layer at the back of the eye).
The nose, which functions for both olfactory and respiratory purposes, can be divided into the external nose and nasal cavity. The external nose consists of both bony and cartilaginous components and opens into the nasal cavity through the anterior nares (nostrils). The lateral wall of the nasal cavity has three pairs of bony projection called turbinates, which help in humidifying the air we inhale. The nasal cavity also drains secretions from four pairs of paranasal sinuses. These paranasal sinuses, located within the bones of the skull, comprise the frontal, sphenoid, ethmoid, and maxillary sinuses. They are an extension of the respiratory system, functioning to moisturise the inspired air.
The oral cavity acts as the beginning of the gastrointestinal tract, with three primary functions of digestion, communication, and breathing. The roof of the mouth consists of the hard and soft palates, whereas the floor of the mouth holds the tongue, salivary glands, and the hyoid muscles. The salivary glands are divided between three pairs of exocrine glands, namely the parotid, submandibular, and sublingual glands.
