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Pheochromocytoma: It is a tumour of the adrenal medulla ( or sympathetic ganglia ) that secretes excess catecholamines ( that is epinephrine and norepinephrine) Adrenal gland has two main layers, cortex and medulla, the cortex is further subdivided into 3 zones and every zone secretes a specific set of hormones. The adrenal medulla secretes epinephrine and norepinephrine. In normal conditions, adrenal medulla secretes catecholamines after the stimulation of the sympathetic nervous system. Hence sympathetic overactivity or adrenal medulla tumour will result in increased secretion of catecholamines. These excessive catecholamines result in symptoms of pheochromocytoma.

Define The Terms: 1) Argyle Robertson Pupil:     It is a pupil that: a) remain constricted b) Doesn't respond to accommodation. Cause : The lesion in the vicinity of the aqueduct of Sylvius and superior colliculi in syphilis of CNS. 2) Horner's Syndrome: It is the collection of symptoms resulting from interruption of sympathetic nerve supply to eyes. Symptoms are; a) Miosis, that is pupil remain constricted. b) Ptosis, that is superior eyelid drops, c) Anhidrosis, that is sweating on the affected side does not occur. d) Vasodilation of blood vessels of the affected side. 3) Xerophthalmia: It is a disease characterized by small triangular white patches on outer and inner sides of cornea. Caused by: Vitamin A deficiency. 4. Keratomalacia: It is a disease in which cornea becomes dull, insensitive and necrotic. Caused by: Severe Vitamin A deficiency. 5. Anisocoria: If two pupils are unequal, this is called anisocoria.

Following disorders predispose to Cor pulmonale or right heart failure. 1. The disease of the pulmonary parenchyma. a) Chronic Obstructive Pulmonary Disease b) Diffuse Pulmonary interstitial fibrosis c) Pneumoconiosis d) Cystic Fibrosis e) Bronchiectasis 2. Disease Of pulmonary vessels. a) Recurrent pulmonary thromboembolism b) Primary Pulmonary Hypertension c) Extensive pulmonary arteritis (eg, in Wegener's granulomatosis) e) Drug, toxin or radiation-induced vascular obstruction f) Extensive pulmonary tumour and micro- embolism 3. Disorders Affecting Chest Movements. a) Kyphoscoliosis b) Marked Obesity (eg, Pickwickian Syndrome) c) Neuromuscular disease 4. Others: a) Metabolic acidosis b) Hypoxemia c) Chronic altitude sickness e) Idiopathic alveolar hypo-ventilation.

Hypothyroidism : Hypothyroidism means " Insufficient secretion of thyroid hormones ( T3 and T4 ) by the thyroid gland. Causes Of hypothyroidism: 1. Thyroid Parenchymal defects: a) A congenital defect in thyroid parenchyma b) Radiation injury to thyroid parenchyma (e.g radio-iodine, external radiation) c) Surgical ablation d) Hashimoto's thyroiditis. 2. Interference with Thyroid hormone synthesis: a) idiopathic primary hypothyroidism (possibly due to immune blockade of TSH receptors) b) Heritable biosynthetic defects c) Iodine deficiency. d) Drugs (e.g iodides, p-aminosalicylic acid, lithium etc) e) Hashimoto Thyroiditis 3. Others: a) Pituitary lesions reducing TSH secretion b) Hypothalamic lesions that reduce thyrotropin-releasing hormone (TRH) secretion. TRH stimulates the pituitary to secrete TSH. Types Of Hypothyroidism: There are three types of hypothyroidism. 1. Primary Hypothyroidism: In primary hypothyroidism, problems lie in the thyroid ...

Spirometry:      It is a process of recording volume movements of air into and out of the lungs. Spirogram: Graphical recording of changes in the lung volume under different              Stages of breathing is called spirogram. Pulmonary Volumes: Tidal Volume: It is the volume of air inspired or expired with each normal breath. its value is 500 ml it means 500 ml of air is inspired in each inspiration and 500 ml of air is expired in each expiration. Inspiratory Reserve Volume: IT is the extra volume of air that can be inspired forcefully over and beyond normal tidal volume. its value is 3000 ml. it means 3000 ml of air can be inspired forcefully beyond tidal volume. Expiratory Reserve Volume. It is the extra volume of air that can be expired forcefully over and beyond the normal tidal volume. Its value is 1100 ml. it means 1100 ml of air other than tidal volume can be expired forcefully. Residual Volume...

Triple Sugar Iron Medium (TSI medium) This medium is prepared in a test tube, the upper portion is called slant and the lower portion is called butt. Composition: 1. Glucose, 2. Sucrose 3. Lactose 4. Ferrous sulphate 5. Tissue extracts (proteins) 6. Phenol red (indicator) Container: Test tube. Colour: Red before reaction (alkaline) yellow after reaction (acidic) Black after hydrogen sulphide gas production due to the formation of FeS. Consistency : Solid medium Uses: This medium is used to differentiate Salmonella and Shigella from other enteric gram-negative rods in stool culture. Micro-organisms/bacteria are cultured. Salmonella and shigella produce:  a). Alkaline slant (red) b). Acidic but with no gas (yellow without bubbles) c) salmonella produces hydrogen sulphide gas but Shigella don't. Other enteric Gram-negative rods produce: a. Acidic slant (yellow) b. Acidic butt with gas ( yellow with bubbles) e.g E. coli Table: Reactions shown by vari...