A branchial cleft cyst is a cyst in the skin of the lateral part of the neck. It can but does not necessarily have an opening to the skin surface called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second branchial cleft, i.e. failure of fusion of the second and third branchial arches. Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly. Most branchial cleft cysts present as a smooth, slowly enlarging lateral neck mass that may increase in size after an upper respiratory tract infection. The fistulas, when present, are asymptomatic, but may become infected. Branchial cleft cysts are remnants of embryonic development and result from a failure of obliteration of one of the branchial clefts, which are homologous to ...
Neural crest cells are a group of temporary, multipotent (can give rise to some other types of cells but not all) cells that are pinched off during the formation of the neural tube (precursor to the spinal cord and brain) and therefore are found at the dorsal (top) region of the neural tube during development. They are derived from the ectoderm germ layer, but are sometimes called the fourth germ layer because they are so important and give rise to so many other types of cells. They migrate throughout the body and create a large number of differentiated cells such as neurons, glial cells, pigment-containing cells in skin, skeletal tissue cells in the head, and many more. Cardiac neural crest cells (CNCCs) are a type of neural crest cells that migrate to the circumpharyngeal ridge (an arc-shape ridge above the pharyngeal arches) and then into the 3rd, 4th and 6th pharyngeal arches and the cardiac outflow tract (OFT). They extend from the otic placodes (the structure in developing embryos that ...
The pharyngeal arches -also known as visceral arches-are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish the arches are known as the branchial arches or gill arches. In the human embryo, the arches are first seen during the fourth week of development. They appear as a series of outpouchings of mesoderm on both sides of the developing pharynx. The vasculature of the pharyngeal arches is known as the aortic arches. In fish, the branchial arches support the gills. In vertebrates, the pharyngeal arches are derived from all three germ layers (the primary layers of cells that form during embryogenesis).Neural crest cells enter these arches where they contribute to features of the skull and facial skeleton such as bone and cartilage. However, the existence of pharyngeal structures before neural crest cells evolved is indicated by the existence of neural crest-independent mechanisms of pharyngeal arch ...
A pharyngeal groove (or branchial groove, or pharyngeal cleft) is made up of ectoderm unlike its counterpart the pharyngeal pouch on the endodermal side. The first pharyngeal groove produces the external auditory meatus (ear canal). The rest (2, 3, and 4) are overlapped by the growing 2nd pharyngeal arch, and form the floor of the depression termed the cervical sinus, which opens ventrally, and is finally obliterated. Branchial cleft cyst "musom.marshall.edu". Retrieved 2009-05-28. http://isc.temple.edu/marino/embryology/parch98/ARCHI97/Img016. ...
A preauricular sinus (also known as a congenital auricular fistula, a congenital preauricular fistula, a Geswein hole, an ear pit, or a preauricular cyst) is a common congenital malformation characterized by a nodule, dent or dimple located anywhere adjacent to the external ear. Frequency of preauricular sinus differs depending the population: 0.1-0.9% in the US, 0.9% in the UK, and 4-10% in Asia and parts of Africa. Comparative frequency is known to be higher in Africans and Asians than in Caucasians. Preauricular sinuses are inherited features, and most often appear unilaterally. They are present bilaterally in 25-50% of cases.[citation needed] Preauricular sinuses and cysts result from developmental defects of the first and second pharyngeal arches. This and other congenital ear malformations are sometimes associated with renal anomalies. They may be present in Beckwith-Wiedemann syndrome, and in rare cases, they may be associated with branchio-oto-renal syndrome.[citation needed] ...
വർണകോശത്തിന്റെ വേർതിരിയലിൽ ഉള്ള തകരാറ് മൂലവും ഭ്രൂണാവസ്ഥയിൽ വർണകോശം ന്യൂറൽ ക്രെസ്റ്റിൽ( neural crest) നിന്ന് തൊലി, മുടി, തൂവൽ തുടങ്ങിയവയിലേക്ക് കുടിയേറുന്നതിലുള്ള തകരാറുകൾ മൂലം ഉണ്ടാകുന്ന സ്ഥൂലരൂപമാണ് ല്യൂക്കിസം. ശരീര ഉപരിതലം ഇത് പൂർണമായോ ഭാഗികമായോ വർണവസ്തുക്കൾ ഉൽപ്പാദിപ്പിക്കാൻ കഴിവുള്ള കോശങ്ങൾ ഇല്ലാതാകുന്നതിന് ഇടയാക്കുന്നു. എല്ലാ വർണവസ്തുക്കളും വിവിധ ശേഷികളുള്ള ഒരേ ...
A branchial cleft cyst is a cyst in the skin of the lateral part of the neck. It can but does not necessarily have an opening to the skin surface called a fistula. The cause is usually a developmental abnormality arising in the early prenatal period, typically failure of obliteration of the second branchial cleft, i.e. failure of fusion of the second and third branchial arches. Less commonly, the cysts can develop from the first, third, or fourth clefts, and their location and the location of associated fistulas differs accordingly. Most branchial cleft cysts present as a smooth, slowly enlarging lateral neck mass that may increase in size after an upper respiratory tract infection. The fistulas, when present, are asymptomatic, but may become infected. Branchial cleft cysts are remnants of embryonic development and result from a failure of obliteration of one of the branchial clefts, which are homologous to ...
A pharyngeal groove (or branchial groove, or pharyngeal cleft) is made up of ectoderm unlike its counterpart the pharyngeal pouch on the endodermal side. The first pharyngeal groove produces the external auditory meatus (ear canal). The rest (2, 3, and 4) are overlapped by the growing 2nd pharyngeal arch, and form the floor of the depression termed the cervical sinus, which opens ventrally, and is finally obliterated. Branchial cleft cyst "musom.marshall.edu". Retrieved 2009-05-28. http://isc.temple.edu/marino/embryology/parch98/ARCHI97/Img016. ...
A Rathke's cleft cyst is a benign growth found on the pituitary gland in the brain, specifically a fluid-filled cyst in the posterior portion of the anterior pituitary gland. It occurs when the Rathke's pouch does not develop properly and ranges in size from 2 to 40mm in diameter. Asymptomatic cysts are commonly detected during autopsies in 2 to 26 percent of individuals who have died of unrelated causes. Females are twice as likely as males to develop a cyst. If a cyst adds pressure to the optic chiasm, it may cause visual disturbances, pituitary dysfunction, and headaches. The majority of pituitary patients with chronic headaches have Rathke's Cleft Cysts. This is believed to be caused by the constant change in volume and the drastic changes in vasopressure from fluctuations in gonadotrophs and ADH. The treatment of choice for symptomatic cysts is drainage and taking a biopsy. Radical excision is more dangerous because of the potential of damaging the patient's pituitary function e.g. ADH ...
Otitis externa is an inflammation of the outer ear and ear canal. Animals are commonly prone to ear infection, and this is one of the most common manifestations of allergy in dogs. In dogs, those breeds with floppy ears are more prone, since air flow is limited and a warm, moist environment built up, which is conducive to infection. The external ear in animals is longer and deeper than in humans, which makes it easier for infection or wax to build up or be hard to remove. Complete ear canal inspection requires the use of an otoscope by a veterinarian. Infections are usually secondary to inflammation or to improper grooming techniques. Infections can be caused by both bacterial and fungal origin, as well as small organisms such as ear mites. Malassezia pachydermatis is a common fungal agent for ear infections in dogs. Staphylococcus intermedius is the most common bacterial infection. A more serious ear infection, with pus in the ear, may be caused by Pseudomonas aeruginosa. Signs of ear infection ...
... (Ciprodex) is an antibiotic/steroid combination product in a sterile suspension. Ciprodex contains the synthetic broad-spectrum antibacterial agent, ciprofloxacin hydrochloride (0.3%), combined with the anti-inflammatory corticosteroid, dexamethasone (0.1%), in a sterile, preserved suspension for otic use. Ciprofloxacin, a fluoroquinolone antibiotic, has shown in vitro activity against many Gram-positive and Gram-negative bacteria including Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenza, Moraxella catarrhalis, and Pseudomonas aeruginosa. Dexamethasone acts as an anti-inflammatory corticosteroid. Ciprodex is indicated for use in the treatment of acute otitis media and acute otitis externa (swimmer's ear) in ages 6 months and older. Ciprodex should be avoided in patients with a history of hypersensitivity to ciprofloxacin or other quinolones and should not be used to treat viral infections. Ciprodex is typically given twice a day in each infected ...
... is a Gram-positive, coagulase-negative member of the bacterial genus Staphylococcus consisting of clustered cocci. It demonstrates limited hemolytic activity, but is does show evidence of urease activity and the ability to use sucrose, mannose, and trehalose. S. felis has been isolated from and is associated with skin infections in cats. Higgins, R; Gottschalk, M (May 1991). "Québec. Isolation of Staphylococcus felis from cases of external otitis in cats". The Canadian veterinary journal. La revue veterinaire canadienne. 32 (5): 312-3. PMC 1481492 . PMID 17423789. Igimi, S.; Kawamura, S.; Takahashi, E.; Mitsuoka, T. (1 October 1989). "Staphylococcus felis, a New Species from Clinical Specimens from Cats". International Journal of Systematic Bacteriology. 39 (4): 373-377. doi:10.1099/00207713-39-4-373. Litster, A. L.; Moss, S. M.; Trott, D. J. (October 1, 2008). "Urinary Tract Infections in Cats". 49 (10): 548. doi:10.1111/j.1748-5827.2008.00650.x. Litster, Annette; Moss, ...
Son bacterias bastante longas pero estreitas, cunha lonxitude comprendida entre 5 e 250 µm e un diámetro de arredor de 0,1-0,7 µm [2]. O citoplasma, membrana plasmática e parede forman o chamado cilindro protoplásmico. Teñen a peculiaridade de posuír unha membrana externa formada por múltiples capas chamada "envoltura celular" ou "vaíña externa" que rodea completamente o cilindro protoplásmico. Spirochaetes distínguese dos demais filos bacterianos pola posesión duns flaxelos especializados denominados filamentos axiais, que non saen ao exterior, xa que están situados entre a envoltura celular externa e o cilindro protoplásmico (no espazo periplásmico). Producen un movemento xiratorio que fai que a bacteria se mova cara a adiante, como se fose un sacarrollas facendo flexións. Segundo a especie, poden ter de dous a 100 destes flaxelos por célula. Os flaxelos son de estrutura e composición similar aos do resto das bacterias, diferenciándose en que son completamente ...