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36-446: The head is the part of an animal or human that usually includes the brain, eyes, ears, nose, and mouth. Head or Heads may also refer to: Head A head is the part of an organism which usually includes the ears , brain , forehead , cheeks , chin , eyes , nose , and mouth , each of which aid in various sensory functions such as sight , hearing , smell , and taste . Some very simple animals may not have

72-407: A carbon dioxide-enriched atmosphere, and share an enhanced capacity to produce endocardial infections, especially in young children. Fusobacterium is a pathogen. The laryngopharynx, ( Latin : pars laryngea pharyngis ), also known as hypopharynx , is the caudal part of the pharynx; it is the part of the throat that connects to the esophagus. It lies inferior to the epiglottis and extends to

108-438: A head, but many bilaterally symmetric forms do, regardless of size. Heads develop in animals by an evolutionary trend known as cephalization . In bilaterally symmetrical animals, nervous tissue concentrate at the anterior region, forming structures responsible for information processing. Through biological evolution, sense organs and feeding structures also concentrate into the anterior region; these collectively form

144-405: A portion of the segments disappear. The head segments also lose most of their systems, except for the nervous system. With the progressive development of cephalization, "the head incorporates more and more of the adjacent segments into its structure, so that in general it may be said that the higher the degree of cephalization the greater is the number of segments composing the head". In the 1980s,

180-417: Is pharyngeal ( / ˌ f æ r ɪ n ˈ dʒ iː əl / or / f ə ˈ r ɪ n dʒ i əl / ). All vertebrates have a pharynx, used in both feeding and respiration. The pharynx arises during development in all vertebrates through a series of six or more outpocketings on the lateral sides of the head. These outpocketings are pharyngeal arches , and they give rise to a number of different structures in

216-400: Is also responsible for the ear-cough reflex in which stimulation of the ear canal results in a person coughing. The pharynx moves food from the mouth to the esophagus. It also moves air from the nasal and oral cavities to the larynx . It is also used in human speech, as pharyngeal consonants are articulated here, and it acts as a resonating chamber during phonation. Inflammation of

252-426: Is noted. When the moray bites prey , it first bites normally with its oral jaws, capturing the prey. Immediately thereafter, the pharyngeal jaws are brought forward and bite down on the prey to grip it; they then retract, pulling the prey down the eel's esophagus, allowing it to be swallowed. Invertebrates also have a pharynx. Invertebrates with a pharynx include the tardigrades , annelids and arthropods , and

288-414: The conducting zone of the respiratory system . (The conducting zone—which also includes the nostrils of the nose , the larynx , trachea , bronchi , and bronchioles —filters, warms and moistens air and conducts it into the lungs ). The human pharynx is conventionally divided into three sections: the nasopharynx , oropharynx , and laryngopharynx . In humans, two sets of pharyngeal muscles form

324-451: The lancelets – have heads, there has been a question of how the vertebrate head, characterized by a bony skull clearly separated from the main body, might have evolved from the head structures of these animals. According to Hyman (1979), the evolution of the head in the vertebrates has occurred by the fusion of a fixed number of anterior segments, in the same manner as in other "heteronomously segmented animals". In some cases, segments or

360-490: The pharyngeal plexus and by the recurrent laryngeal nerve . The vascular supply to the laryngopharynx includes the superior thyroid artery , the lingual artery and the ascending pharyngeal artery . The primary neural supply is from both the vagus and glossopharyngeal nerves. The vagus nerve provides an auricular branch also termed "Arnold's nerve" which also supplies the external auditory canal, thus laryngopharyngeal cancer can result in referred ear pain . This nerve

396-409: The "new head hypothesis" was proposed, suggesting that the vertebrate head is an evolutionary novelty resulting from the emergence of neural crest and cranial placodes . In 2014, a transient larva tissue of the lancelet was found to be virtually indistinguishable from the neural crest-derived cartilage which forms the vertebrate skull, suggesting that persistence of this tissue and expansion into

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432-403: The 4th and 6th cervical vertebrae , the superior boundary of the laryngopharynx is at the level of the hyoid bone . The laryngopharynx includes three major sites: the pyriform sinus , postcricoid area, and the posterior pharyngeal wall. Like the oropharynx above it, the laryngopharynx serves as a passageway for food and air and is lined with a stratified squamous epithelium . It is innervated by

468-425: The auditory tube , somewhat triangular in shape and bounded behind by a firm prominence, the torus tubarius or cushion, caused by the medial end of the cartilage of the tube that elevates the mucous membrane . Two folds arise from the cartilaginous opening: The oropharynx lies behind the oral cavity, extending from the uvula to the level of the hyoid bone . It opens anteriorly, through the isthmus faucium , into

504-404: The backside of the labrum flanking the side of the mouth, succeeded by a pair of maxillae each of which is known as maxilliary palp . At the back side of the mouth is the labium or lower lip. There is also an extra mouth part in some insects which is termed as hypopharynx which is usually located between the maxillac . Though invertebrate chordates – such as the tunicate larvae or

540-418: The developing pharynx of amphioxi and hemichordates . However, the vertebrate pharynx is unique in that it gives rise to endoskeletal support through the contribution of neural crest cells. Pharyngeal jaws are a "second set" of jaws contained within the pharynx of many species of fish, distinct from the primary (oral) jaws. Pharyngeal jaws have been studied in moray eels where their specific action

576-473: The entire headspace could be a viable evolutionary route to formation of the vertebrate head. The heads of humans and other animals are commonly recurring charges in heraldry . Heads of humans are sometimes blazoned simply as a "man's head", but are far more frequently described in greater detail, either characteristic of a particular race or nationality (such as Moors' heads, Saxons' heads, Egyptians' heads or Turks' heads), or specifically identified (such as

612-405: The form of segmented attachments, in pairs, that are usually located between the eyes. These are in varying shapes and sizes, in the form of filaments or in different enlarged or clubbed form. Insects have mouth parts in various shapes depending on their feeding habits. Labrum is the "upper lip" which is in the front area of the head and is the most exterior part. A pair of mandibles is found on

648-611: The head encloses billions of "miniagents and microagents (with no single Boss)". The evolution of a head is associated with the cephalization that occurred in Bilateria some 555 million years ago. In some arthropods , especially trilobites , the cephalon , or cephalic region, is the region of the head which is a collective of "fused segments". A typical insect head is composed of eyes, antennae , and components of mouth. As these components differ substantially from insect to insect, they form important identification links. Eyes in

684-405: The head found, in several types of insects, are in the form of a pair of compound eyes with multiple faces. In many other types of insects, the compound eyes are seen in a "single facet or group of single facets". In some cases, the eyes may be seen as marks on the dorsal or located near or toward the head, two or three ocelli (single faceted organs). Antennae on the insect's head is found in

720-529: The head of Moses in the crest of Hilton, or the head of St. John the Baptist in the crest of the London Company of Tallowchandlers). Several varieties of women's heads also occur, including maidens' heads (often couped under the bust, with hair disheveled), ladies' heads, nuns' heads (often veiled), and occasionally queens' heads. The arms of Devaney of Norfolk include "three nun's heads veiled couped at

756-407: The head. The human head is an anatomical unit that consists of the skull , hyoid bone and cervical vertebrae . The term "skull" collectively denotes the mandible (lower jaw bone) and the cranium (upper portion of the skull that houses the brain). ) ] Sculptures of human heads are generally based on a skeletal structure that consists of a cranium, jawbone , and cheekbone . Though

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792-423: The location where this common pathway diverges into the respiratory ( laryngeal ) and digestive ( esophageal ) pathways. At that point, the laryngopharynx is continuous with the esophagus posteriorly. The esophagus conducts food and fluids to the stomach; air enters the larynx anteriorly. During swallowing, food has the "right of way", and air passage temporarily stops. Corresponding roughly to the area located between

828-407: The lower end at the fourth stage. Eyes and chins are fitted in various shapes to form the head. Leonardo da Vinci , considered one of the world's greatest artists, drew sketches of human anatomy using grid structures. His image of the face drawn on the grid structure principle is in perfect proportion. In this genre, using the technique of pen and ink, Leonardo created a sketch which is a "Study on

864-400: The middle ear to the pharynx, opens into the nasopharynx at the pharyngeal opening of the auditory tube. The opening and closing of the auditory tubes serves to equalize the barometric pressure in the middle ear with that of the ambient atmosphere. The anterior aspect of the nasopharynx communicates through the choanae with the nasal cavities. On its lateral wall is the pharyngeal opening of

900-459: The mouth as the free apex of the rostral epiglottis lies dorsal to the soft palate in a normal horse. In ruminants , the tonsils are a compact mass that points towards the lumen of the pharynx. Pharyngeal arches are characteristic features of vertebrates whose origin can be traced back through chordates to basal deuterostomes who also share endodermal outpocketings of the pharyngeal apparatus. Similar patterns of gene expression can be detected in

936-432: The mouth, while in its lateral wall, between the palatoglossal arch and the palatopharyngeal arch , is the palatine tonsil . The anterior wall consists of the base of the tongue and the epiglottic vallecula ; the lateral wall is made up of the tonsil, tonsillar fossa, and tonsillar (faucial) pillars; the superior wall consists of the inferior surface of the soft palate and the uvula. Because both food and air pass through

972-457: The number of muscles making up the face is generally consistent between sculptures, the shape of the muscles varies widely based on the function, development, and expressions reflected on the faces of the subjects. Proponents of identism believe that the mind is identical to the brain. Philosopher John Searle asserts his identist beliefs, stating "the brain is the only thing in the human head". Similarly, Dr. Henry Bennet-Clark has stated that

1008-467: The pharyngeal tonsils, are lymphoid tissue structures located in the posterior wall of the nasopharynx. Waldeyer's tonsillar ring is an annular arrangement of lymphoid tissue in both the nasopharynx and oropharynx. The nasopharynx is lined by respiratory epithelium that is pseudostratified, columnar, and ciliated. Polyps or mucus can obstruct the nasopharynx, as can congestion due to an upper respiratory infection. The auditory tube , which connects

1044-407: The pharynx and determine the shape of its lumen . They are arranged as an inner layer of longitudinal muscles and an outer circular layer. The upper portion of the pharynx, the nasopharynx, extends from the base of the skull to the upper surface of the soft palate . It includes the space between the internal nares and the soft palate and lies above the oral cavity. The adenoids , also known as

1080-437: The pharynx, a flap of connective tissue called the epiglottis closes over the glottis when food is swallowed to prevent aspiration . The oropharynx is lined by non-keratinized squamous stratified epithelium. The HACEK organisms ( H aemophilus , A ctinobacillus actinomycetemcomitans , C ardiobacterium hominis , E ikenella corrodens , K ingella ) are part of the normal oropharyngeal flora, which grow slowly, prefer

1116-404: The pharynx, or pharyngitis , is the painful inflammation of the throat. Pharyngeal cancer is a cancer that originates in the neck and/or throat. Waldeyer's tonsillar ring is an anatomical term collectively describing the annular arrangement of lymphoid tissue in the pharynx. Waldeyer's ring circumscribes the naso- and oropharynx, with some of its tonsillar tissue located above and some below

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1152-403: The proportions of head and eyes" (pictured). An idiom is a phrase or a fixed expression that has a figurative, or sometimes literal, meaning. The head's function and appearance play an analogous role in the etymology of many technical terms. Cylinder head , pothead , and weatherhead are three such examples. Hypopharynx In humans, the pharynx is part of the digestive system and

1188-419: The shape of the head in the shape of an egg. The female head, in particular, is sketched in a double circle design procedure with proportions considered as an ideal of a female head. In the first circle, the division is made of five sections on the diameter , each section of five eyes width. It is then developed over a series of ten defined steps, with the smaller circle imposed partially over the larger circle at

1224-452: The shoulders proper," and the bust of a queen occurs in the arms of Queenborough, Kent . Infants' or children's heads are often couped at the shoulders with a snake wrapped around the neck (e.g. "Argent, a boy's head proper, crined or, couped below the shoulders, vested gules, tarnished gold," in the arms of Boyman). One of the ways of drawing sketches of heads—as Jack Hamm advises—is to develop it in six well-defined steps, starting with

1260-447: The skeletal, muscular, and circulatory systems. The structure of the pharynx varies across the vertebrates. It differs in dogs, horses, and ruminants. In dogs, a single duct connects the nasopharynx to the nasal cavity. The tonsils are a compact mass that points away from the lumen of the pharynx. In the horse, the auditory tube opens into the guttural pouch and the tonsils are diffuse and raised slightly. Horses are unable to breathe through

1296-571: The soft palate (and to the back of the oral cavity). It is believed that Waldeyer's ring prevents the invasion of microorganisms from going into the air and food passages and this helps in the defense mechanism of the respiratory and alimentary systems. The word pharynx ( / ˈ f ær ɪ ŋ k s / ) is derived from the Greek φάρυγξ phárynx , meaning "throat". Its plural form is pharynges / f ə ˈ r ɪ n dʒ iː z / or pharynxes / ˈ f ær ɪ ŋ k s ə z / , and its adjective form

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