anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

, the palatine bones (; derived from the Latin ''palatum'') are two

irregular bone The irregular bones are bones which, from their peculiar form, cannot be grouped as long, short, flat or sesamoid bones. Irregular bones serve various purposes in the body, such as protection of nervous tissue (such as the vertebrae protect the ...

s of the

facial skeleton The facial skeleton comprises the ''facial bones'' that may attach to build a portion of the skull. The remainder of the skull is the neurocranium. In human anatomy and development, the facial skeleton is sometimes called the ''membranous visc ...

in many animal species, located above the

uvula The uvula (: uvulas or uvulae), also known as the palatine uvula or staphyle, is a conic projection from the back edge of the middle of the soft palate, composed of connective tissue containing a number of racemose glands, and some muscular fi ...

in the

throat In vertebrate anatomy, the throat is the front part of the neck, internally positioned in front of the vertebrae. It contains the Human pharynx, pharynx and larynx. An important section of it is the epiglottis, separating the esophagus from the t ...

. Together with the

maxilla In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...

, they comprise the

hard palate The hard palate is a thin horizontal bony plate made up of two bones of the facial skeleton, located in the roof of the mouth. The bones are the palatine process of the maxilla and the horizontal plate of palatine bone. The hard palate spans ...

Structure

The palatine bones are situated at the back of the

nasal cavity The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nas ...

between the

and the pterygoid process of the sphenoid bone. They contribute to the walls of three cavities: the floor and lateral walls of the nasal cavity, the roof of the mouth, and the floor of the orbits. They help to form the pterygopalatine and

pterygoid fossa The pterygoid fossa is an anatomical term for the fossa formed by the divergence of the lateral pterygoid plate and the medial pterygoid plate of the sphenoid bone. Structure The lateral and medial pterygoid plates (of the pterygoid process ...

e, and the

inferior orbital fissure The inferior orbital fissure is a gap between the Greater wing of sphenoid bone, greater wing of sphenoid bone, and the maxilla. It connects the Orbit (anatomy), orbit (anteriorly) with the infratemporal fossa and pterygopalatine fossa (posterio ...

s. Each palatine bone somewhat resembles the letter L, and consists of a

horizontal plate The horizontal plate of palatine bone is a quadrilateral part of the palatine bone, and has two surfaces and four borders. Surfaces The superior surface, concave from side to side, forms the back part of the floor of the nasal cavity. The infe ...

, a perpendicular plate, and three projecting processes—the pyramidal process, which is directed backward and lateral from the junction of the two parts, and the orbital and sphenoidal processes, which surmount the vertical part, and are separated by a deep notch, the sphenopalatine notch. The two plates form the posterior part of the hard palate and the floor of the nasal cavity; anteriorly, they join with the maxillae. The two horizontal plates articulate with each other at the posterior part of the median palatine suture and more anteriorly with the maxillae at the transverse palatine suture. The human palatine articulates with six bones: the sphenoid,

ethmoid The ethmoid bone (; from ) is an unpaired bone in the skull that separates the nasal cavity from the brain. It is located at the roof of the nose, between the two orbit (anatomy), orbits. The cubical (cube-shaped) bone is lightweight due to a sp ...

inferior nasal concha The inferior nasal concha (inferior turbinated bone or inferior turbinal/turbinate) is one of the three paired nasal conchae in the human nose, nose. It extends horizontally along the lateral wall of the nasal cavity and consists of a wikt:lam ...

vomer The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

and opposite palatine. There are two important foramina in the palatine bones that transmit nerves and blood vessels to this region: the greater and lesser palatine. The larger

greater palatine foramen The greater palatine foramen is, along with the lesser palatine foramen, one of two foramina (holes) in each of the left and right palatine bones which form the posterior roof of the human mouth, known as the palate. It is sometimes known as the ...

is located in the posterolateral region of each of the palatine bones, usually at the apex of the maxillary third molar. The greater palatine foramen transmits the greater palatine nerve and blood vessels. A smaller opening nearby, the

lesser palatine foramen The lesser palatine foramina are a pair of foramina (openings) on each of the palatine bones, which form the posterior roof of the human mouth. They are sometimes referred to as the minor palatine foramina. The lesser palatine foramina form a pass ...

, transmits the lesser palatine nerve and blood vessels to the soft palate and tonsils. Both foramina are openings of the pterygopalatine canal that carries the descending palatine nerves and blood vessels from the pterygopalatine fossa to the palate.

Function

The

sphenopalatine foramen The sphenopalatine foramen is a foramen of the skull that connects the nasal cavity and the pterygopalatine fossa. It gives passage to the sphenopalatine artery, nasopalatine nerve, and the superior nasal nerve (all passing from the pterygopala ...

is the opening between the sphenoid bone and orbital processes of the palatine bone; it opens into the nasal cavity and gives passage to branches from the pterygopalatine ganglion and the

sphenopalatine artery The sphenopalatine artery (nasopalatine artery) is an artery of the head, commonly known as the artery of epistaxis. It passes through the sphenopalatine foramen to reach the nasal cavity. It is the main artery of the nasal cavity. Course The sp ...

from the maxillary artery.

Other animals

bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...

, the palatine bone consists of the perpendicular plate only, lying on the inner edge of the maxilla. The lower surface of the bone may bear several teeth, forming a second row behind those of the maxilla; in many cases, these are actually larger than the maxillary teeth. Although a similar pattern was present in primitive

tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

s, the palatine bone is reduced in most living

amphibian Amphibians are ectothermic, anamniote, anamniotic, tetrapod, four-limbed vertebrate animals that constitute the class (biology), class Amphibia. In its broadest sense, it is a paraphyletic group encompassing all Tetrapod, tetrapods, but excl ...

s, forming, in

frog A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order (biology), order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough ski ...

s and

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

s, only a narrow bar between the vomer and maxilla. Early fossil

reptile Reptiles, as commonly defined, are a group of tetrapods with an ectothermic metabolism and Amniotic egg, amniotic development. Living traditional reptiles comprise four Order (biology), orders: Testudines, Crocodilia, Squamata, and Rhynchocepha ...

s retained the arrangement seen in more primitive vertebrates, but in

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

s, the lower surface of the palatine became folded over during evolution, forming the horizontal plate, and meeting in the midline of the mouth. This forms the rear of the

, separating the oral and nasal cavities, and making it easier to breathe while eating. A

parallel Parallel may refer to: Mathematics * Parallel (geometry), two lines in the Euclidean plane which never intersect * Parallel (operator), mathematical operation named after the composition of electrical resistance in parallel circuits Science a ...

development has occurred to varying degrees in many living reptiles, reaching its greatest extent in

crocodilian Crocodilia () is an Order (biology), order of semiaquatic, predatory reptiles that are known as crocodilians. They first appeared during the Late Cretaceous and are the closest living relatives of birds. Crocodilians are a type of crocodylomorp ...

s. In

bird Birds are a group of warm-blooded vertebrates constituting the class (biology), class Aves (), characterised by feathers, toothless beaked jaws, the Oviparity, laying of Eggshell, hard-shelled eggs, a high Metabolism, metabolic rate, a fou ...

s, the palatine bones remain separate, long the sides of the rear part of the upper jaw, and typically have a mobile articulation with the

cranium The skull, or cranium, is typically a bony enclosure around the brain of a vertebrate. In some fish, and amphibians, the skull is of cartilage. The skull is at the head end of the vertebrate. In the human, the skull comprises two prominent ...

. There are numerous variations amongst mammals, amphibians and other species. For example, the palatine bone in many amphibians such as the

rough-skinned newt The rough-skinned newt or roughskin newt (''Taricha granulosa'') is a North American newt known for the strong toxin exuded from its skin. Appearance A stocky newt with rounded snout, it ranges from light brown to olive or brownish-black on t ...

manifests as a distinct V-shaped structure. In the case of cat species, the horizontal and a vertical elements join at a 45-degree angle.

Additional images

File:Orbital_bones.png, The seven bones which articulate to form the orbit. File:Gray167.png, Articulation of left palatine bone with maxilla. File:Gray187.png, Base of skull. Inferior surface. File:Gray192.png, Medial wall of left orbit. File:Gray196.png, Roof, floor, and lateral wall of left nasal cavity. File:Gray168.png, Medial aspect of left palatine bone. File:Gray169.png, Posterior aspect of left palatine bone.

References

External links