Definition Pleural effusion is a collection of fluid in the pleural space between the visceral pleura surounding the lungs and the parietal pleural attatched to the throacic wall. Demographics Pleural effusions are relatively common, but it is a manifestation of other underlying diseases. The prevalence and incidence of pleural effusions is therefore dependent on it's cause. Pathophysiology/causes Pleural fluid is usually filtered from the parietal pleura into the pleural space, due to hydrostatic pressure from the capillaries, negative pressure in the pleural space and pleural oncotic pressure. The visceral pleura is perfused by the pulmonary system which has a lower pressure, and fluid in the pleural space is therefore drawn back in through the visceral pleura due to the higher oncotic pressure in plasma. Some of this fluid is then drained by the lymphatic system.
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...
Describing lesions Site, Distribution and symmetry Type of lesion Size Shape - edges, well demarcated? regular/irregular shape? Surface -color and texture, scaly vs non-scaly (epidermis lesions are scaly) Special features - fluid filled?, mobility, temperature/inflammation, other features.
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