Parts of the head
Parts of the head cancion
The head is the upper part of the body, and upper or anterior part of many animals, where some sense organs and the brain are located: the human body consists of head, trunk and limbs.
The head (or «testa», which can be either the head itself or the forehead), of an animal, is the anterior part of the body containing the mouth, brain and various sense organs (usually organs of vision, hearing, smell and taste).
The highest degree of cephalization occurs in arthropods (especially insects) and vertebrates; in these animals, the head is clearly differentiated from the rest of the body and provided with very efficient sensory organs.
The simplest animals, such as sponges, and those with radial symmetry (cnidarians and ctenophores) do not have a head, but most forms with bilateral symmetry (Bilateria) do; these animals have an anterior-posterior axis so that the brain and sensory organs are concentrated in the anterior part of the body; the degree of cephalization is variable in the different bilateral phyla; many have an incipient head (flatworms, annelids, nematodes, mollusks). Within the bilaterals, there are also headless groups such as bivalves, bryozoans, echinoderms, etc.
Parts of the neck
«Head and neck» is a broad, general term in oncology used to refer to the areas of this region that are most susceptible to cancer and do not include the brain, eye, esophagus (food pipe), thyroid glands, scalp, skin, bone, or blood; these are not classified as head and neck cancers. «Head and neck» refers primarily to the oral cavity, salivary glands, pharynx, larynx, nasal cavity and sinuses. Combined, these parts perform a variety of functions and make up several different systems.
The oral cavity, also known as the mouth, includes the gums, lips, tongue, hard palate or bone at the top of the mouth and the lower mouth under the tongue. The oral cavity is used for chewing, tasting, swallowing and manipulating air to form words.3
Salivary glands are glands found in the oral cavity (mouth) and throat. There are three types of salivary glands; the parotid gland secretes saliva near the upper teeth, the submandibular gland secretes saliva under the tongue, and the sublingual gland secretes saliva from the floor of the mouth. This saliva contains enzymes that chemically break down food to begin the process of digestion.4
Anatomy of the head
The head consists of the skull, face, scalp, teeth, brain, cranial nerves, meninges, special sensory organs and other structures such as blood vessels, lymphatic vessels and fat. It is also the place where food is eaten and air is inhaled and exhaled.
The bones of the head are divided into two parts: the Neurocranium and the Facial Skeleton (Viscerocranium). The neurocranium provides the envelope for the brain and cerebral meninges, the proximal parts of the cranial nerves and blood vessels.
Parts of the face
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The head is located at the top of the body and consists of a spheroidal framework of flat bones enclosing very delicate organs, such as the control, recording and data processing center called the encephalon.
The lower back part of the head, located under the base of the skull, is called the nape of the neck; the lower front part, located under the lower jaw, is called the throat. The surrounding part, together with the anterior parts, forms a narrowing that joins the head to the trunk and is called the neck.
Through the neck run the cervical vertebrae, located at the back, which hold the head to the spine and through the interior of the spine runs the important bundle of nerves called the spinal cord.