Medical Science Test 2 Nddc Scholarship

A pH below 7.35 indicates acidosis. Because the bicarbonate (\(HCO_3\)) and Base Excess (BE) are also low, the primary driver of this imbalance is metabolic. Bicarbonate acts as a buffer; when its levels drop, the blood becomes more acidic. Since the \(pCO_2\) remains within the neutral range, it indicates that the respiratory system has not yet compensated for the acid-base disturbance (which it would normally do by hyperventilating to lower \(CO_2\)). This pattern is typically seen in conditions like diabetic ketoacidosis or severe renal failure.

The Tuberculin Skin Test (TST) is read by measuring the diameter of induration (palpable, raised, hardened area) across the forearm. For persons with no known risk factors for TB, an induration of less than 15 mm is considered negative. However, in low-risk screening contexts, a measurement of 0 to 4 mm is a definitively negative result. It is important to note that redness (erythema) is not measured; only the hard, raised area is significant for determining if the immune system has been sensitized to the TB bacteria.

Squamous cell carcinoma was traditionally the most common type of lung cancer and remains highly prevalent among smokers. It usually arises in the central portion of the lungs, within the larger bronchi. While Adenocarcinoma has recently overtaken it in overall frequency in many Western populations (especially among non-smokers and women), Squamous cell remains a classic 'most common' answer in many medical examinations focusing on central lung pathologies and smoking-related oncology.

Type II alveolar cells (or Type II pneumocytes) are specialized cuboidal cells that cover about 5% of the alveolar surface. Their primary function is to synthesize and secrete pulmonary surfactant, a complex mixture of phospholipids and proteins. Surfactant reduces the surface tension at the air-liquid interface of the alveoli, preventing them from collapsing at the end of expiration and significantly reducing the work required for breathing. Type I cells, by contrast, are thin and flat to facilitate gas exchange.

Stridor is a loud, high-pitched, wheezing sound heard during inspiration. It is caused by disrupted airflow through a narrowed or obstructed upper airway (trachea or larynx). It is often a medical emergency, seen in conditions like epiglottitis, croup, or foreign body aspiration. Rhonchi are low-pitched snoring sounds typically caused by secretions in larger lower airways, and wheezes are high-pitched sounds usually associated with lower airway narrowing, such as in asthma.

The standard normal range for arterial \(pCO_2\) is 35 to 45 mm Hg. Since carbon dioxide acts as an acid in the blood (forming carbonic acid), its level is tightly regulated by the lungs. A \(pCO_2\) level above 45 mm Hg (hypercapnia) indicates respiratory acidosis or hypoventilation, while a level below 35 mm Hg (hypocapnia) indicates respiratory alkalosis or hyperventilation.

The normal range for bicarbonate (\(HCO_3\)) in the blood is typically 22 to 26 mEq/L (though some laboratories use 22-28 mEq/L). Bicarbonate is the primary base (buffer) in the body's extracellular fluid, and its concentration is regulated by the kidneys. Levels below 22 mEq/L suggest metabolic acidosis, while levels above 26 mEq/L suggest metabolic alkalosis.

Pentamidine is an antimicrobial medication used specifically to treat and prevent Pneumocystis pneumonia (PCP). It is typically used as a second-line treatment for patients who cannot tolerate the first-line choice, which is trimethoprim-sulfamethoxazole (TMP-SMX). Allopurinol is used for gout, Lorazepam is a benzodiazepine for anxiety, and Chlorpropamide is a medication for diabetes. Pentamidine works by interfering with the synthesis of DNA, RNA, and proteins in the protozoan-like fungus.

The male urethra consists of three main parts: the prostatic urethra (passing through the prostate), the membranous urethra (passing through the urogenital diaphragm), and the penile (or spongy) urethra (passing through the penis). 'Vasapore' is not an anatomical term related to the urinary or reproductive system. The correct anatomical term for the opening of the vas deferens into the urethra is the ejaculatory duct, which enters at the prostatic segment.

Glucosuria (or glycosuria) occurs when the blood glucose level is so high (usually above 180 mg/dL) that the kidneys cannot reabsorb all the filtered glucose in the proximal tubule. Uremia refers to the accumulation of nitrogenous waste in the blood due to kidney failure, ureteritis is inflammation of the ureter, and glucose intolerance is a metabolic state associated with pre-diabetes but is not a name for glucose in the urine.