Depressor septi nasi muscle
The depressor septi arises from the incisive fossa of the maxilla. Its fibers ascend to be inserted into the nasal septum and back part of the alar part of nasalis muscle, it lies between the mucous membrane and muscular structure of the lip. The depressor septi is a direct antagonist of the other muscles of the nose, drawing the ala of the nose downward, thereby constricting the aperture of the nares. Works like the alar part of the nasalis muscle; this article incorporates text in the public domain from page 382 of the 20th edition of Gray's Anatomy
Gray's Anatomy is an English language textbook of human anatomy written by Henry Gray and illustrated by Henry Vandyke Carter. Earlier editions were called Anatomy: Descriptive and Surgical, Anatomy of the Human Body and Gray's Anatomy: Descriptive and Applied, but the book's name is shortened to, editions are titled, Gray's Anatomy; the book is regarded as an influential work on the subject, has continued to be revised and republished from its initial publication in 1858 to the present day. The latest edition of the book, the 41st, was published in September 2015; the English anatomist Henry Gray was born in 1827. He studied the development of the endocrine glands and spleen and in 1853 was appointed Lecturer on Anatomy at St George's Hospital Medical School in London. In 1855, he approached his colleague Henry Vandyke Carter with his idea to produce an inexpensive and accessible anatomy textbook for medical students. Dissecting unclaimed bodies from workhouse and hospital mortuaries through the Anatomy Act of 1832, the two worked for 18 months on what would form the basis of the book.
Their work was first published in 1858 by John William Parker in London. It was dedicated by Gray to 1st Baronet. An imprint of this English first edition was published in the United States in 1859, with slight alterations. Gray prepared a second, revised edition, published in the United Kingdom in 1860 by J. W. Parker. However, Gray died the following year, at the age of 34, having contracted smallpox while treating his nephew, his death had come just three years after the initial publication of his Anatomy Descriptive and Surgical. So, the work on his much-praised book was continued by others. Longman's publication began in 1863, after their acquisition of the J. W. Parker publishing business; this coincided with the publication date of the third British edition of Gray's Anatomy. Successive British editions of Gray's Anatomy continued to be published under the Longman, more Churchill Livingstone/Elsevier imprints, reflecting further changes in ownership of the publishing companies over the years.
The full American rights were purchased by Blanchard and Lea, who published the first of twenty-five distinct American editions of Gray's Anatomy in 1862, whose company became Lea & Febiger in 1908. Lea & Febiger continued publishing the American editions until the company was sold in 1990; the first American publication was edited by Richard James Dunglison, whose father Robley Dunglison was physician to Thomas Jefferson. Dunglison edited the next four editions; these were: the Second American Edition. W. W. Keen edited the next two editions, namely: the New American from the Eleventh English Edition. In September 1896, reference to the English edition was dropped and it was published as the Fourteenth Edition, edited by Bern B. Gallaudet, F. J. Brockway, J. P. McMurrich, who edited the Fifteenth Edition. There is an edition dated 1896 which does still reference the English edition stating it is "A New Edition, Thoroughly Revised by American Authorities, from the thirteenth English Edition" and edited by T. Pickering Pick, F.
R. C. S. and published by Lea Brothers & Co. Philadelphia and New York; the Sixteenth Edition was edited by J. C. DaCosta, the Seventeenth by DaCosta and E. A. Spitzka. Spitzka edited the Eighteenth and Nineteenth editions, in October 1913, R. Howden edited the New American from the Eighteenth English Edition; the "American" editions continued with consecutive numbering from the Twentieth onwards, with W. H. Lewis editing the 20th, 21st, 22nd, 23rd, 24th. C. M. Gross edited the 25th, 26th, 27th, 28th, 29th. Carmine D. Clemente extensively revised the 30th edition. With the sale of Lea & Febiger in 1990, the 30th edition was the last American Edition. Sometimes separate editing efforts with mismatches between British and American edition numbering led to the existence, for many years, of two main "flavours" or "branches" of Gray's Anatomy: the U. S. and the British one. This can cause misunderstandings and confusion when quoting from or trying to purchase a certain edition. For example, a comparison of publishing histories shows that the American numbering kept apace with the British up until the 16th editions in 1905, with the American editions either acknowledging the English edition, or matching the numbering in the 14th, 15th and 16th editions.
The American numbering crept ahead, with the 17th American edition published in 1908, while the 17th British edition was published in 1909. This increased to a three-year gap for the 18th and 19th editions, leading to the 1913 publication of the New American from the Eighteenth English, which brought the numbering back into line. Both 20th editions were published in the same year. Thereafter, it was the British numbering that pushed ahead, with the 21st British edition in 1920, the 21st American edition in 1924; this discrepancy continued to increase, so that the 30th British edition was published in 1949, while the 30th and last American edition was published in 1984. The newest, 41st edition of Gray's Anatomy was published on 25 September 2015 by Elsevier in both print and online versions, and
The temporal muscle known as the temporalis, is one of the muscles of mastication. It is a broad, fan-shaped muscle on each side of the head that fills the temporal fossa, superior to the zygomatic arch so it covers much of the temporal bone. In humans, it arises from the deep part of temporal fascia, it passes medial to the zygomatic arch and forms a tendon which inserts onto the coronoid process of the mandible, with its insertion extending into the retromolar fossa posterior to the most distal mandibular molar. In other mammals, the muscle spans the dorsal part of the skull all the way up to the medial line. There, it may be attached to a sagittal crest, as can be seen in early hominins like Paranthropus aethiopicus; the temporal muscle is covered by the temporal fascia known as the temporal aponeurosis. This fascia is used in tympanoplasty, or surgical reconstruction of the eardrum; the muscle is accessible on the temples, can be seen and felt contracting while the jaw is clenching and unclenching.
The temporalis is derived from the first pharyngeal arch in development. As with the other muscles of mastication, control of the temporal muscle comes from the third branch of the trigeminal nerve; the muscle is innervated by the deep temporal nerves. The muscle receives its blood supply from the deep temporal arteries which anastomose with the middle temporal artery; the temporal muscle is the most powerful muscle of the temporomandibular joint. The temporal muscle can be divided into two functional parts; the anterior portion its contraction results in elevation of the mandible. The posterior portion has fibers which run horizontally and contraction of this portion results in retrusion of the mandible; when lower dentures are fitted, they should not extend into the retromolar fossa to prevent trauma of the mucosa due to the contraction of the temporalis muscle. The temporalis is to be involved in jaw pain and headaches. Bruxism, the habitual grinding of teeth while sleeping, clenching of the jaw while stressed can lead to overwork of the temporalis and results in pain.
A myotendinous rupture of the temporalis can occur during a seizure due to extreme clenching of the jaw. During a seizure the contralateral temporalis muscle can enter spastic paralysis, this clenching in extreme cases can lead to a rupture on the myotendinous insertion at the coronoid process of the mandible. Anatomy photo:27:04-0100 at the SUNY Downstate Medical Center - "Infratemporal Fossa: The Temporalis Muscle" The anatomical basis for surgical preservation of temporal muscle, Kadri, et al. J Neurosurg 2004, 100:517–522 at http://www.mc.vanderbilt.edu/documents/singerlab/files/Kadri%20et%20al.pdf Temporalis Muscle Transfer, The Methodist Hospital System, Houston, TX, at http://www.methodistfacialparalysis.com/temporalis/
Superior rectus muscle
The superior rectus muscle is a muscle in the orbit. It is one of the extraocular muscles, it is innervated by the superior division of the oculomotor nerve. In the primary position, the superior rectus muscle's primary function is elevation, although it contributes to intorsion and adduction, it elevates and helps intort the eye. The superior rectus muscle is the only muscle, capable of elevating the eye when it is in a abducted position. Anatomy figure: 29:01-02 at Human Anatomy Online, SUNY Downstate Medical Center "Diagram". Archived from the original on March 25, 2010
Levator palpebrae superioris muscle
The levator palpebrae superioris is the muscle in the orbit that elevates the superior eyelid. The levator palpebrae superioris originates on the lesser wing of the sphenoid bone, just above the optic foramen, it decreases in thickness and becomes the levator aponeurosis. This portion inserts on the skin of the upper eyelid, as well as the superior tarsal plate, it is a skeletal muscle. The superior tarsal muscle, a smooth muscle, is attached to the levator palpebrae superioris, inserts on the superior tarsal plate as well; as with most of the muscles of the orbit, the levator palpebrae receives somatic motor input from the ipsilateral superior division of the oculomotor nerve. An adjoining smooth muscle, the superior tarsal muscle, confused to be a portion of the levator palpebrae superioris, is only attached, it is separately innervated by sympathetic fibers that originate in the cervical spinal cord; the levator palpebrae superioris muscle retracts the upper eyelid. Damage to this muscle or its innervation can cause ptosis, drooping of the eyelid.
Lesions in CN III can cause ptosis, because without stimulation from the oculomotor nerve the levator palpebrae cannot oppose the force of gravity, the eyelid droops. Ptosis can result from damage to the adjoining superior tarsal muscle or its sympathetic innervation; such damage to the sympathetic supply presents as a partial ptosis. It is important to distinguish between these two different causes of ptosis; this can be done clinically without issue, as each type of ptosis is accompanied by other distinct clinical findings. Blepharospasm Ptosis Superior tarsal muscle Anatomy figure: 29:01-01 at Human Anatomy Online, SUNY Downstate Medical Center lesson3 at The Anatomy Lesson by Wesley Norman
Orbicularis oris muscle
In human anatomy, the orbicularis oris muscle is a complex of muscles in the lips that encircles the mouth. Until it was misinterpreted as a sphincter, or circular muscle, but it is composed of four independent quadrants that interlace and give only an appearance of circularity, it is one of the muscles used in the playing of all brass instruments and some woodwind instruments. This muscle puckers the lips when it contracts; the orbicularis oris is not a simple sphincter muscle like the orbicularis oculi. It consists of fibers derived from the other facial muscles which are inserted into the lips, of fibers proper to the lips. Of the former, a considerable number are derived from the buccinator and form the deeper stratum of the orbicularis; some of the buccinator fibers—namely, those near the middle of the muscle—decussate at the angle of the mouth, those arising from the maxilla passing to the lower lip, those from the mandible to the upper lip. The uppermost and lowermost fibers of the buccinator pass across the lips from side to side without decussation.
Superficial to this stratum is a second, formed on either side by the caninus and triangularis, which cross each other at the angle of the mouth. In addition to these, fibers from the quadratus labii superioris, the zygomaticus, the quadratus labii inferioris intermingle with the transverse fibers above described, have principally an oblique direction; the proper fibers of the lips are oblique, pass from the under surface of the skin to the mucous membrane, through the thickness of the lip. Fibers occur by which the muscle is connected with the maxillæ and the septum of the nose above and with the mandible below. In the upper lip, these consist of two bands and medial, on either side of the middle line; the interval between the two medial bands corresponds with the depression, called the philtrum, seen on the lip beneath the septum of the nose. The additional fibers for the lower lip constitute a slip m. incisivus labii inferioris on either side of the middle line. Babies are born without one or both sides of this particular muscle, resulting in a slight droop to the affected side of the face.
This article incorporates text in the public domain from page 384 of the 20th edition of Gray's Anatomy Anatomy figure: 23:02-03 at Human Anatomy Online, SUNY Downstate Medical Center "Anatomy diagram: 25420.000-1". Roche Lexicon - illustrated navigator. Elsevier. Archived from the original on 2014-01-01. Facial Muscles - BBC Picture of the circular-shaped muscle Facial Muscles - BBC Animation of movements of the muscle
Superior tarsal muscle
The superior tarsal muscle is a smooth muscle adjoining the levator palpebrae superioris muscle that helps to raise the upper eyelid. The superior tarsal muscle originates on the underside of levator palpebrae superioris and inserts on the superior tarsal plate of the eyelid; the superior tarsal muscle receives its innervation from the sympathetic nervous system. Postganglionic sympathetic fibers originate in the superior cervical ganglion, travel via the internal carotid plexus, where small branches communicate with the oculomotor nerve as it passes through the cavernous sinus; the sympathetic fibres continue to the superior division of the oculomotor nerve, where they enter the superior tarsal muscle on its inferior aspect. The superior tarsal muscle works to keep the upper eyelid raised after the levator palpebrae superioris has raised the upper eyelid. Damage to some elements of the sympathetic nervous system can inhibit this muscle, causing a drooping eyelid; this is seen in Horner's syndrome.
The ptosis seen in Horner's syndrome is of a lesser degree than is seen with an oculomotor nerve palsy. The muscle derives its name from Greek ταρσός, meaning'flat surface' used for drying; the term Müller's muscle is sometimes used as a synonym. However, the same term is used for the circular fibres of the ciliary muscle, for the orbitalis muscle that covers the inferior orbital fissure. Given the possible confusion, the use of the term Müller's muscle should be discouraged unless the context removes any ambiguity. Heinrich Müller