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Ear Victor
An ear is the organ that enables hearing and, in mammals, body balance using the vestibular system. In mammals, the ear is usually described as having three parts—the outer ear, the middle ear and the inner ear. The outer ear consists of the pinna and the ear canal. Since the outer ear is the only visible portion of the ear in most animals, the word "ear" often refers to the external part alone. The middle ear includes the tympanic cavity and the three ossicles. The inner ear sits in the bony labyrinth, and contains structures which are key to several senses: the semicircular canals, which enable balance and eye tracking when moving; the utricle and saccule, which enable balance when stationary; and the cochlea, which enables hearing. The ears of vertebrates are placed somewhat symmetrically on either side of the head, an arrangement that aids sound localisation. The ear develops from the first pharyngeal pouch and six small swellings that develop in the ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saccule
The saccule is a bed of sensory cells in the inner ear. It translates head movements into neural impulses for the brain to interpret. The saccule detects linear accelerations and head tilts in the vertical plane. When the head moves vertically, the sensory cells of the saccule are disturbed and the neurons connected to them begin transmitting impulses to the brain. These impulses travel along the vestibular portion of the eighth cranial nerve to the vestibular nuclei in the brainstem. The vestibular system is important in maintaining balance, or equilibrium. The vestibular system includes the saccule, utricle, and the three semicircular canals. The vestibule is the name of the fluid-filled, membranous duct that contains these organs of balance. The vestibule is encased in the temporal bone of the skull. Structure The saccule, or sacculus, is the smaller of the two vestibular sacs. It is globular in form and lies in the recessus sphæricus near the opening of the vest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Churchill Livingstone
Churchill Livingstone is an academic publisher. It was formed in 1971 from the merger of Longman's medical list, E & S Livingstone (Edinburgh, Scotland) and J & A Churchill (London, England) and was owned by Pearson. Harcourt acquired Churchill Livingstone in 1997. It is now integrated as an imprint in Elsevier's health science division after Elsevier acquired Harcourt in 2001. In the past it published a number of classic medical texts, including Sir William Osler's textbook '' The Principles and Practice of Medicine, Gray's Anatomy,'' and ''Myles In Greek mythology, Myles (; Ancient Greek: Μύλης means 'mill-man') was an ancient king of Laconia. He was the son of the King Lelex and possibly the naiad Queen Cleocharia, and brother of Polycaon. Myles was the father of Eurotas who begott ...' Textbook for Midwives.'' In the 1980s, in addition to new texts in all areas of clinical medicine, it published an extensive list of medical and nursing textbooks in low-cost editions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earring
An earring is a piece of jewelry attached to the ear via a piercing in the earlobe or another external part of the ear (except in the case of clip earrings, which clip onto the lobe). Earrings have been worn by people in different civilizations and historic periods, often with cultural significance. Locations for piercings other than the earlobe include the rook, tragus, and across the helix (see image at right). The simple term "ear piercing" usually refers to an earlobe piercing, whereas piercings in the upper part of the external ear are often referred to as "cartilage piercings". Cartilage piercings are more complex to perform than earlobe piercings and take longer to heal. Earring components may be made of any number of materials, including metal, plastic, glass, precious stone, beads, wood, bone, and other materials. Designs range from small hoops and studs to large plates and dangling items. The size is ultimately limited by the physical capacity of the earlobe to hold the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vertigo
Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties walking. It is typically worse when the head is moved. Vertigo is the most common type of dizziness. The most common disorders that result in vertigo are benign paroxysmal positional vertigo (BPPV), Ménière's disease, and labyrinthitis. Less common causes include stroke, brain tumors, brain injury, multiple sclerosis, migraines, trauma, and uneven pressures between the middle ears. Physiologic vertigo may occur following being exposed to motion for a prolonged period such as when on a ship or simply following spinning with the eyes closed. Other causes may include toxin exposures such as to carbon monoxide, alcohol, or aspirin. Vertigo typically indicates a problem in a part of the vestibular system. Other causes of dizziness incl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balance Disorders
A balance disorder is a disturbance that causes an individual to feel unsteady, for example when standing or walking. It may be accompanied by feelings of giddiness, or wooziness, or having a sensation of movement, spinning, or floating. Balance is the result of several body systems working together: the visual system (eyes), vestibular system (ears) and proprioception (the body's sense of where it is in space). Degeneration or loss of function in any of these systems can lead to balance deficits. Signs and symptoms Cognitive dysfunction (disorientation) may occur with vestibular disorders. Cognitive deficits are not just spatial in nature, but also include non-spatial functions such as object recognition memory. Vestibular dysfunction has been shown to adversely affect processes of attention and increased demands of attention can worsen the postural sway associated with vestibular disorders. Recent MRI studies also show that humans with bilateral vestibular damage (damage to bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tinnitus
Tinnitus is the perception of sound when no corresponding external sound is present. Nearly everyone experiences a faint "normal tinnitus" in a completely quiet room; but it is of concern only if it is bothersome, interferes with normal hearing, or is associated with other problems. While often described as a ringing, it may also sound like a clicking, buzzing, hissing or roaring. It may be soft or loud, low- or high- pitched, and may seem to come from one or both ears or from the head itself. In some people, it may interfere with concentration, and in some cases is associated with anxiety and depression. Tinnitus is usually associated with a degree of hearing loss and decreased comprehension of speech in noisy environments. It is common, affecting about 10–15% of people. Most, however, tolerate it well, and it is a significant problem in only 1–2% of all people. It can trigger a fight-or-flight response, as the brain may perceive it as dangerous and important. The word ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
