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Parotid Gland
The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the mandibular ramus, and secretes serous saliva through the parotid duct into the mouth, to facilitate mastication and swallowing and to begin the digestion of starches. There are also two other types of salivary glands; they are submandibular and sublingual glands. Sometimes accessory parotid glands are found close to the main parotid glands. The venom glands of snakes are a modification of the parotid salivary glands. Etymology The word ''parotid'' literally means "beside the ear". From Greek παρωτίς (stem παρωτιδ-) : (gland) behind the ear < παρά - pará : in front, and οὖς - ous (stem ὠτ-, ōt-) : ear. Structure The parotid glands are a pair of mainly[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestion
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into the blood stream. Digestion is a form of catabolism that is often divided into two processes based on how food is broken down: mechanical and chemical digestion. The term mechanical digestion refers to the physical breakdown of large pieces of food into smaller pieces which can subsequently be accessed by digestive enzymes. Mechanical digestion takes place in the mouth through Chewing, mastication and in the small intestine through segmentation contractions. In chemical digestion, enzymes break down food into the small compounds that the body can use. In the human digestive system, food enters the mouth and mechanical digestion of the food starts by the action of mastication (chewing), a form of mechanical digestion, and the wetting contact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temporal Bone
The temporal bone is a paired bone situated at the sides and base of the skull, lateral to the temporal lobe of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples where four of the cranial bones fuse. Each temple is covered by a temporal muscle. The temporal bones house the structures of the ears. The lower seven cranial nerves and the major vessels to and from the brain traverse the temporal bone. Structure The temporal bone consists of four parts—the squamous, mastoid, petrous and tympanic parts. The squamous part is the largest and most superiorly positioned relative to the rest of the bone. The zygomatic process is a long, arched process projecting from the lower region of the squamous part and it articulates with the zygomatic bone. Posteroinferior to the squamous is the mastoid part. Fused with the squamous and mastoid parts and between the sphenoid and occipital bones lies the petrous part, which is shaped li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Anatomical Variations
This article provides a comprehensive list of anatomical variations, which are naturally occurring differences in human morphology. These variations are not considered defects or abnormalities but rather normal deviations that do not inherently indicate pathology. Head and neck Skeletal variations * Occipitalization of the atlas * Basilar tubercle of clivus * Tubercle at the anterior rim of foramen magnum * Clivus bony canal * Condylus tertius * Epipteric bone * Foramen tympanicum * Ossified petrosphenoid ligament * Ossification anomalies of the atlas (C1) * Craniopharyngeal canal * Canalis basilaris medianus * Fossa navicularis magna * Transverse basilar fissure (Saucer's fissure) (see Clivus) * Arcus praebasiocipitalis * Stafne bone cavity * Arcuate foramen * Ossiculum terminale (of dens) * Os odontoideum * Intermediate condylar canal * Innominate canal of Arnold * Arcus praebasiocipitalis * Inca bone * Haller cell * Sphenoethmoidal air cell (Onodi cell) (see Sphe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillary Artery
The maxillary artery (eg, internal maxillary artery) supplies deep structures of the face. It branches from the external carotid artery just deep to the neck of the mandible. Structure The maxillary artery, the larger of the two terminal branches of the external carotid artery, arises behind the neck of the Human mandible, mandible, and is at first imbedded in the substance of the parotid gland; it passes forward between the ramus of the mandible and the sphenomandibular ligament, and then runs, either superficial or deep to the lateral pterygoid muscle, to the pterygopalatine fossa. It supplies the deep structures of the face, and may be divided into Human mandible, mandibular, Pterygoid processes of the sphenoid, pterygoid, and pterygopalatine ganglion, pterygopalatine portions. First portion The ''first'' or ''mandibular '' or ''bony'' portion passes horizontally forward, between the neck of the mandible and the sphenomandibular ligament, where it lies parallel to and a little ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Great Auricular Nerve
The great auricular nerve is a Cutaneous nerve, cutaneous (sensory) nerve of the head. It originates from the second and third spinal nerve, cervical (spinal) nerves (C2-C3) of the cervical plexus. It provides sensory innervation to the skin over the parotid gland and the Mastoid part of the temporal bone, mastoid process, parts of the outer ear, and to the parotid gland and its parotid fascia, fascia. Pain resulting from parotitis is caused by an impingement on the great auricular nerve. Structure The great auricular nerve is the largest of the ascending branches of the cervical plexus. Origin It arises from the second and third cervical (spinal) nerves (C2-C3), with the predominant contribution coming from C2. Course and relations The great auricular nerve is a large trunk that ascends almost vertically over the sternocleidomastoid. It winds around the posterior border of the sternocleidomastoid muscle, then perforates the deep fascia before ascending alongside the exter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superficial Temporal Artery
In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic arch, above and in front of the tragus of the ear. Structure The superficial temporal artery is the smaller of two end branches that split superiorly from the external carotid. Based on its direction, the superficial temporal artery appears to be a continuation of the external carotid. It begins within the parotid gland, behind the neck of the mandible, and passes superficially over the posterior root of the zygomatic process of the temporal bone; about 5 cm above this process it divides into two branches: ''a. frontal'', and ''a. parietal''. Branches The parietal branch of the superficial temporal artery (posterior temporal) is a small artery in the head. It is larger than the frontal branch and curves upward and backward on the si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Carotid Artery
The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland. Structure Origin The external carotid artery arises from the common carotid artery just inferior to the upper border of the thyroid cartilage. At its origin, this artery is closer to the skin and more medial than the internal carotid, and is situated within the carotid triangle. Course and fate It curves to pass anterosuperiorly before inclining posterior-ward to reach the space posterior the neck of the mandible, where it divides into the superficial temporal and maxillary artery within the parotid gland. It rapidly diminishes in size as it travels up the neck, owing to the number and large size of its branches. Relations At the origin, external carotid artery is more medial than internal carotid artery. When external carotid artery ascends the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retromandibular Vein
The retromandibular vein (temporomaxillary vein, posterior facial vein) is a major vein of the face. It is formed within the parotid gland by the confluence of the maxillary vein, and superficial temporal vein. It descends in the gland and splits into two branches upon emerging from the gland. Its ''anterior branch'' then joins the (anterior) facial vein forming the common facial vein, while its ''posterior branch'' joins the posterior auricular vein forming the external jugular vein. Anatomy Origin The retromandibular vein is formed within the parotid gland by the confluence of the maxillary vein, and superficial temporal vein. Course It descends inside parotid gland, superficial to the external carotid artery (but beneath the facial nerve), between the sternocleidomastoideus muscle and ramus of mandible. It emerges from the parotid gland inferiorly, then immediately divides into two branches: * an ''anterior branch'' which passes anterior-ward to unite with the (a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Facial Nerve
The facial nerve, also known as the seventh cranial nerve, cranial nerve VII, or simply CN VII, is a cranial nerve that emerges from the pons of the brainstem, controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue. The nerve typically travels from the pons through the facial canal in the temporal bone and exits the skull at the stylomastoid foramen. It arises from the brainstem from an area posterior to the cranial nerve VI (abducens nerve) and anterior to cranial nerve VIII (vestibulocochlear nerve). The facial nerve also supplies preganglionic parasympathetic fibers to several head and neck ganglia. The facial and intermediate nerves can be collectively referred to as the nervus intermediofacialis. The path of the facial nerve can be divided into six segments: # intracranial (cisternal) segment (from brainstem pons to internal auditory canal) # meatal (canalicular) segment (with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and axes. The meaning of terms that are used can change depending on whether a vertebrate is a biped or a quadruped, due to the difference in the neuraxis, or if an invertebrate is a non-bilaterian. A non-bilaterian has no anterior or posterior surface for example but can still have a descriptor used such as proximal or distal in relation to a body part that is nearest to, or furthest from its middle. International organisations have determined vocabularies that are often used as standards for subdisciplines of anatomy. For example, '' Termi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxillary Second Molar
The maxillary second molar is the tooth located distally (away from the midline of the face) from both the maxillary first molars of the mouth but mesial (toward the midline of the face) from both maxillary third molars. This is true only in permanent teeth. In deciduous (baby) teeth, the maxillary second molar is the last tooth in the mouth and does not have a third molar behind it. The function of this molar is similar to that of all molars in regard to grinding being the principal action during mastication, commonly known as chewing. There are usually four cusps on maxillary molars, two on the buccal (side nearest the cheek) and two palatal (side nearest the palate). There are great differences between the deciduous In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, aft ... ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buccinator Muscle
The bucinator () is a thin quadrilateral muscle occupying the interval between the maxilla and the Human mandible, mandible at the side of the face. It forms the anterior part of the cheek or the lateral wall of the oral cavity.Illustrated Anatomy of the Head and Neck, Fehrenbach and Herring, Elsevier, 2012, page 91 Structure It arises from the outer surfaces of the alveolar processes of the maxilla and Human mandible, mandible, corresponding to the three pairs of molar teeth and in the mandible, it is attached upon the buccinator crest, bucinator crest Anatomical terms of location#Anterior and posterior, posterior to the third molar; and behind, from the Anatomical terms of location#Anterior and posterior, anterior border of the pterygomandibular raphe which separates it from the constrictor pharyngis superior. The fibers converge toward the angle of the mouth, where the central fibers intersect each other, those from below being continuous with the upper segment of the orbicula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
