Glandular branches of facial artery
The glandular branches of the facial artery consist of three or four large vessels, which supply the submandibular gland, some being prolonged to the neighboring muscles, lymph glands, integument. This article incorporates text in the public domain from page 555 of the 20th edition of Gray's Anatomy
The submental artery is a branch of the facial artery that runs on the underside of the chin. The submental artery is the largest of the cervical branches of the facial artery, given off just as that vessel leaves the submandibular gland: it runs forward upon the mylohyoid, just below the body of the mandible, beneath the digastric muscle, it supplies the surrounding muscles, anastomoses with the sublingual artery and with the mylohyoid branch of the inferior alveolar artery. The submental vessels supply a territory of skin in the submental area. Surgeons can use the skin and vessels in reconstruction of the oral cavity; when the submental artery turns upward over the border of the mandible it divides into a superficial and a deep branch. The superficial branch passes between the integument and depressor labii inferioris, anastomoses with the inferior labial artery; the deep branch runs between the muscle and the bone, supplies the lip, anastomoses with the inferior labial artery and the mental branch of the inferior alveolar artery.
This article incorporates text in the public domain from page 555 of the 20th edition of Gray's Anatomy
Ascending pharyngeal artery
The ascending pharyngeal artery is an artery in the neck that supplies the pharynx, developing from the proximal part of the embryonic second aortic arch. It is the smallest branch of the external carotid and is a long, slender vessel seated in the neck, beneath the other branches of the external carotid and under the stylopharyngeus muscle, it lies just superior to the bifurcation of the common carotid arteries. The artery most bifurcates into embryologically distinct pharyngeal and neuromeningeal trunks; the pharyngeal trunk consists of several branches which supply the middle and inferior pharyngeal constrictor muscles and the stylopharyngeus, ramifying in their substance and in the mucous membranes lining them. These branches are in hemodynamic equilibrium with contributors from the internal maxillary artery; the neuromeningeal trunk classically consists of jugular and hypoglossal divisions, which enter the jugular and hypoglossal foramina to supply regional meningeal and neural structures, being in equilibrium with branches of the vertebral, posterior meningeal, middle meningeal, internal carotid arteries.
Present is the inferior tympanic branch, which ascends towards the middle ear cavity. The muscular branch of the ascending pharyngeal artery is in equilibrium with the odontoid arcade from the vertebral artery, it arises from the back part of the external carotid, near the commencement of that vessel, ascends vertically between the internal carotid and the side of the pharynx, to the under surface of the base of the skull, lying on the longus capitis. This article incorporates text in the public domain from page 557 of the 20th edition of Gray's Anatomy http://neuroangio.org/anatomy-and-variants/ascending-pharyngeal-artery/
Circle of Willis
The circle of Willis is a circulatory anastomosis that supplies blood to the brain and surrounding structures. It is named after an English physician; the circle of Willis is a part of the cerebral circulation and is composed of the following arteries: Anterior cerebral artery Anterior communicating artery Internal carotid artery Posterior cerebral artery Posterior communicating artery The middle cerebral arteries, supplying the brain, are not considered part of the circle. The left and right internal carotid arteries arise from the left and right common carotid arteries; the posterior communicating artery is given off as a branch of the internal carotid artery just before it divides into its terminal branches - the anterior and middle cerebral arteries. The anterior cerebral artery forms the anterolateral portion of the circle of Willis, while the middle cerebral artery does not contribute to the circle; the right and left posterior cerebral arteries arise from the basilar artery, formed by the left and right vertebral arteries.
The vertebral arteries arise from the subclavian arteries. The anterior communicating artery connects the two anterior cerebral arteries and could be said to arise from either the left or right side. All arteries involved give off central branches; the central branches supply the interior of the circle of Willis, more the Interpeduncular fossa. The cortical branches are named for the area. Since they do not directly affect the circle of Willis, they are not dealt with here. Considerable anatomic variation exists in the circle of Willis. Based on a study of 1413 brains, the classic anatomy of the circle is only seen in 34.5% of cases. In one common variation the proximal part of the posterior cerebral artery is narrow and its ipsilateral posterior communicating artery is large, so the internal carotid artery supplies the posterior cerebrum. In another variation the anterior communicating artery is a large vessel, such that a single internal carotid supplies both anterior cerebral arteries; the arrangement of the brain's arteries into the circle of Willis creates redundancy for collateral circulation in the cerebral circulation.
If one part of the circle becomes blocked or narrowed or one of the arteries supplying the circle is blocked or narrowed, blood flow from the other blood vessels can preserve the cerebral perfusion well enough to avoid the symptoms of ischemia. The redundancies that the circle of Willis introduce can lead to reduced cerebral perfusion. In subclavian steal syndrome, blood is "stolen" from the circle of Willis to preserve blood flow to the upper limb. Subclavian steal syndrome results from a proximal stenosis of the subclavian artery, an artery supplied by the aorta, the same blood vessel that feeds the circle of Willis via the vertebral artery. Cerebral circulation Leptomeningeal collateral circulation
Lateral nasal branch of facial artery
The lateral nasal branch of facial artery is derived from the facial artery as that vessel ascends along the side of the nose. It supplies the ala and dorsum of the nose, anastomosing with its fellow, with the septal and alar branches, with the dorsal nasal branch of the ophthalmic artery, with the infraorbital branch of the internal maxillary. If the posterior lateral nasal artery is superficial in the nasal wall, a laceration may occur during an aggressive curettage. A sinus floor elevation procedure requires a separation and elevation of the sinus lining with subsequent introduction of space maintaining graft material. During the lining elevation this artery may be cut in the osseous nasal wall; this article incorporates text in the public domain from page 556 of the 20th edition of Gray's Anatomy http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-5. HTM
Head and neck anatomy
This article describes the anatomy of the head and neck of the human body, including the brain, muscles, blood vessels, glands, mouth, teeth and throat. The head rests on the top part of the vertebral column, with the skull joining at C1; the skeletal section of the head and neck forms the top part of the axial skeleton and is made up of the skull, hyoid bone, auditory ossicles, cervical spine. The skull can be further subdivided into: the cranium, the facial bones; the occipital bone joins with the atlas near the foramen magnum, a large hole at the base of the skull. The atlas the axis below; the spinal cord passes through the foramen magnum. The head and neck is covered in skin and its appendages, termed the integumentary system; these include hair, sweat glands, sebaceous glands, sensory nerves. The skin is made up of three microscopic layers: epidermis and hypodermis; the epidermis is composed of stratified squamous epithelium and is divided into the following five sublayers or strata, listed in order from outer to inner: Stratum corneum, Stratum lucidum, Stratum granulosum, Stratum spinosum, Stratum germinativum called stratum basale.
The deepest layer is stratum basale producing daughter cells by mitosis. The mouth called the oral cavity, is the entranceway into the digestive system containing both primary and accessory organs of digestion. Two rows of teeth are supported by facial bones of the skull, the maxilla above and the mandible below. Adults have 32 permanent teeth, children have 20 deciduous teeth. There are various tooth shapes for different jobs. For example, when chewing, the upper teeth work together with the lower teeth of the same shape to bite and tear food; the names of these teeth are: Incisors. They have chisel-shaped crowns that cut food. Cuspids, the four cuspids are next to each incisor. Cuspids have a pointed edge to tear food. Premolars, the four pairs of molars are located next to the cuspids, they tear food. Molars, there are twelve molars, in sets of three, at the back of the mouth, they have wide surfaces. The white visible part of a tooth is called the crown; the rounded upper projections of the back teeth are cusps.
The hard white exterior covering of the tooth is the enamel. As the tooth tapers below the gumline, the neck is formed. Below the neck, holding the tooth into the bone, is the root of the tooth; the inner portions of the tooth consist of the dentin, a bonelike tissue, the pulp. The pulp is a soft tissue area containing the nerve and blood vessels to nourish and protect the tooth, located within the pulp cavity. A tooth sits in a specialized socket called the alveolus; the tooth is held in location with the assistance of cementum. Teeth are surrounded by gingiva, or gums, part of the periodontium, support tissue of oral cavity protection; the periodontium includes all of the support membranes of the dental structures surround and support the teeth such as the gums and the attachment surfaces and membranes. These include connective tissues, muscle tissue and nervous tissue. There are three sets of salivary glands: the submandibular and the sublingual glands; the glands secrete saliva for proper mixing of food and provides enzymes to start chemical digestion.
Saliva helps to hold together the formed bolus, swallowed after chewing. Saliva is composed of water, salivary amylase and trace amounts of urea; the tongue is a specialized skeletal muscle, specially adapted for the activities of speech, developing gustatory sense and swallowing. The tongue contains two sets of muscles, the intrinsic- involved with shape of tongue, the extrinsic- involved with tongue movement, it is attached to the hyoid bone. Terms meaning tongue include "glosso" and "lingual" (; the outer surfaces of the head and neck are lined by epithelium. The protective tissues of the oral cavity are continuous with the digestive tract are called mucosa or mucous membranes; the cells of the inner oral cavity are called the buccal mucosa. The oral cavity is lined by a stratified squamous epithelium containing about three layers of cells, they line the oral and external auditory meatus, providing lubrication and protection against pathogens. The lips are protected by specialized sensory cells called Meissner's corpuscles.
Blood circulates from the upper systemic loop originating at the aortic arch, includes: the brachiocephalic artery, left common carotid artery and left subclavian artery. The head and neck are emptied of blood by the subclavian jugular vein; the brachiocephalic artery or trunk is the first and largest artery that branches to form the right common carotid artery and the right subclavian artery. This artery provides blood to the right upper chest, right arm and head, through a branch called right vertebral artery; the right and left vertebral artery feed into the basilar artery and upward to the Posterior cerebral artery, which provides most of the brain with oxygenated blood. The posterior cerebral artery and the posterior communicating artery are within the circle of Willis; the left common carotid artery divides to form the: internal carotid artery and an external carot
Posterior meningeal artery
The posterior meningeal artery is the largest vessel supplying the dura region of the posterior fossa. It arises from the ascending pharyngeal artery although other origins have been seen, such as the occipital artery; the artery or its branches enter the cranium through jugular foramen, foramen magnum or hypoglossal canal. MeningesThis article incorporates text in the public domain from page 558 of the 20th edition of Gray's Anatomy Diagnostic Cerebral Angiography, 2nd edition, Anne G. Osborn