The head is complex, but functional. Like the rest of the body, the head consists of skin, bone, blood vessels and nerves. However, the head also contains most sensory organs, such as the nose, eyes, ears and mouth. These structures, along with the brain, make the head the most important part of the body.
Bone
The skull consists of four parts called the calvarium, cranium, mandible and skull. According to the Biological Anthropology Web, the four parts consist of 14 bones. They include the ethmoid bone supporting the nasal cavity, the frontal bones that form the forehead and top of the eye sockets, the inferior nasal conchae and lacrimal bone, which forms structures inside the skull. The bone forming the lower jaw, called the mandible, holds the lower teeth. The upper jawbone formed by the maxillae contains the upper teeth. Forming the bridge of the nose is the nasal bone. The palatine, vomer and sphenoid bones form the inner skull and upper palate. The occipital, parietal, temporal and zygomatic bones form the back, top and sides of the head.
Brain
The brain is a complex organ. It consists of four lobes that control your senses and actions. In addition, it has an internal structure that controls emotions called the limbic system. The American Health Assistance Foundation describes the brain as consisting of the frontal lobe, which controls skilled movement and decision-making; the parietal lobe, which controls sensory input and math skills; the temporal lobe, responsible for processing hearing and language; and the occipital lobe, for vision processing.
The limbic system consists of many structures controlling emotions, learning and memories. One structure of the limbic system, called the hippocampus, thought to be the first area affected by Alzheimer's disease, controls the formation of memory.
The Eyes
Each eye socket consists of six bones. The eyes are set with an orientation to the front of the head. The eye has three different sections. The fibrous section consists of the sclera, the canal of Schlemm and cornea. The vascular section consists of the choroid, ciliary body, muscle and iris, and the retina, with a nerve supply, is the nervous section of the eye.
The Ears
The ear consists of three parts. The external ear contains the pinna, exterior meatus, glands and outer eardrum. The middle ear contains the ossicles, facial nerve, chorda typani, inner eardrum and the auditory tube. In addition, the inner ear contains the labyrinth.
Cranial Nerves
Twelve cranial nerves provide sensory and motor control to structures in the head. They are the olfactory I, optic II, oculomotor III, trochlear IV, trigeminal V, abducens VI, facial VII, auditory (vestibulocochlear) VIII, glossopharyngeal IX, vagus X, spinal Accessory XI and the hypoglossal XII.
