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Showing posts from May, 2013

Facial nerves

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5 main branches of the facial nerve: To Zanzibar By Motor Car Temporal Zygomatic Buccal Mandibular Cervical

Otitis Media with Effusion (Glue ear)

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Definition: Inflammation of the middle ear with the collection of fluid, without acute signs of inflammation. Also known as glue ear. Pathophysiology:  The pathophysiology of glue ear is not fully known, however it is thought to be associated with Eustachian tube dysfunction. This is either thought to lead to a sterile accumulation of fluids that predisposes the middle ear to infections, or is thought to cause more acute infections of the middle ear that then leads to chronic effusion. Children with cleft palate also often have glue ear as their tensor veli palatini muscle does not attatch properly to the soft palate such that the Eustachian tube does not open on swallowing or mouth opening.

Innervation of the vocal cords

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The vocal cords are innervated by the superior laryngeal nerve and the recurrent laryngeal nerves which are branches of the vagus nerve (cranial nerve X). The superior laryngeal nerve splits into the external and internal branches. The internal branch contains sensory nerves from the larynx whereas the external branch supplies the cricothyroid muscle which tenses the vocal cords. Damage to the superior laryngeal nerves can be caused by thyroid surgery. Unilateral damage to the superior laryngeal nerve causes slight voice changes, usually affecting pitch. Bilateral damage to the superior laryngeal nerves reduces the ability for the vocal cords to close increasing the risk of aspiration. The recurrent laryngeal nerves supply the other muscles of the vocal cords, including the posterior cricoarytenoid muscle which is the only muscle which opens the vocal cords. The recurrent laryngeal nerves have a different course on the left and the right. The left is longer and descends down to...

Community acquired pneumonia

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Definition:  Pneumonia is the inflammation of the terminal bronchioles and alveoli, characterised by consolidation of the affected part by inflammatory cells, exudate and fibrin. Pneumonia is most commonly caused by infection. Community acquired pneumonia is defined as pneumonia presenting in the community or in the first 2 days of hospital admission. Pneumonia occurring after this time is more likely to be hospital acquired and caused by a different set of mircoorganisms.

Diabetic Ketoacidosis (Adults)

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Definition : A major life threatening metabolic condition occurring in diabetic patients leading to hyperglycaemia , ketoacidosis , dehydration and ketonuria . Pathophysiology:  The lack of insulin primarily leads to hyperglycaemia and ketonaemia:  Insulin insufficiency leads to reduced uptake of glucose into cells and increased blood concentration of glucose.  As glucose are not taken into cells, alternative sources of energy are used.  Most cells break down fatty acids instead of glucose which forms ketones. Ketone levels therefore reflects the glucose deficit in cells.  Lack of insulin also leads to an increase in opposing hormones which lead to increased glycogenolysis, gluconeogenesis and lipolysis. 

Syncope differentials

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Definition: The transient loss of conciousness caused by transient global hypoperfusion of the brain. Syncope is sudden onset, occurs for a short duration, and is characterised by spontaneous complete recovery. Causes and Differentials:  Syncope presents as a transient loss of conciousness but is defined by its pathophysiology (transient global hypoperfusion) and is therefore different to other causes of loss of conciousness. Syncope can be divided into 3 main types which are summarised below:  Reflex syncope is the most common type.  

Notes on Pediatrics

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Patterns of childhood illnesses