স্পেশাল বিসিএস (স্বাস্থ্য) - লং কোর্স

A characteristic feature of the pineal gland is the presence of variously sized concretions of calcium and magnesium salts called corpora arenacea, or brain sand, formed by mineralization of extracellular protein deposits.

In the distal convoluted tubules of the renal cortex, PTH stimulates Ca2+ reabsorption (and inhibits phosphate reabsorption in the proximal tubules).

When the body is at rest, approximately 70% of the blood moves through the systemic circulation, about 18% through the pulmonary circulation, and 12% through the heart.

Capillaries have only an endothelium, with no subendothelial layer or other tunics.

No explanation added.

The beating of the cilia moves mucus lying on the surface of the epithelium of the conducting zone, and any contained dust, up out of the bronchial tree.

The cribriform plate of the ethmoid bone has many foramina through which pass olfactory nerves that transmit sensory information from inhaled air to the olfactory bulbs.

Negative pressure (suction) causes the visceral pleura to remain in contact with the parietal pleura, so that when the chest wall & parietal pleura move, the parietal pleura takes the visceral pleura and lungs with it.

The thyroid is a highly vascular, butterfly-shaped gland surrounding the anterior surface of the trachea just below the larynx.

The parathyroid glands are four small nodules normally embedded in the capsule on the posterior surface of the thyroid gland.

The hypothalamic hypophyseal tract includes bundles of nerve axons that run from supraoptic nucleus (SON) and paraventricular nucleus (PVN) in the hypothalamus to the posterior pituitary.

During ventricular systole, blood should flow through the aortic valve into the aorta and not back into the left atrium. The mitral valve prevents blood going back into the left atrium.

The fossa ovalis is the slight depression that remains when the foramen ovale closes.

The blood supply to the brain has continuous capillaries (in the blood-brain barrier), the SI has fenestrated capillaries (to facilitate absorption of digestion products), the liver has sinusoids.

Bronchodilation is stimulated by sympathetic nerve impulses, adrenalin & noradrenalin. Bronchoconstriction triggered by parasympathetic nerve impulses.

Oxytocin stimulates milk ejection by acting on mammary gland

The fibrous skeleton is a dense framework of collagen within the heart that keeps the orifices of the atrioventricular (AV) valves and semilunar valve patent, provides an attachment site of the valve leaflets and cusps, serves as the origin and insertion sites of cardiac myocytes, and forms an electrical “barrier” between the atria and ventricles so that they contract independently.

The bronchial veins carry deoxygenated blood from the bronchial arteries that supply large bronchi. Right bronchial veins drain into the azygos vein. Left bronchial veins drain into the accessory hemiazygos vein.

The trachea is a tube composed of 16 to 20 U-shaped hyaline cartilages and the trachealis muscle. The trachea begins just inferior to the cricoid cartilage (C6 vertebral level) and ends at the sternal angle (T4 vertebral level), where it bifurcates into the right main bronchus and the left main bronchus. At the bifurcation of the trachea, the last tracheal cartilage forms the carina, which can be observed by bronchoscopy as a raised ridge of tissue in the sagittal plane.