Tag: science & technology

The pituitary gland is called the master gland because it secretes hormones that control other endocrine glands, including thyroid, adrenal glands, and reproductive glands. The pancreas regulates blood sugar, thyroid regulates metabolism, and spleen is part of the immune system - none control other glands.

Newborn infants have approximately 300 bones, many of which fuse together during growth through ossification. Adults typically have 206 bones. The reduction occurs as skull bones, spine vertebrae, and pelvic bones merge. Options 206, 230, and 280 are all incorrect for newborns.

Vitamin A (retinol) is essential for healthy vision, particularly night vision, and maintaining the cornea. Deficiency causes night blindness and eventually total blindness. Vitamin B aids metabolism, Vitamin C supports immunity, and Vitamin D regulates calcium absorption - none primarily support vision.

The normal resting heart rate for adults is 60-100 beats per minute, with 72 bpm often cited as the average. A rate of 70 bpm falls within this healthy range. Rates of 50 bpm (borderline bradycardia), 80 bpm (normal but high), and 100 bpm (tachycardia threshold) are less representative of the average.

Blood group AB individuals have both A and B antigens on their red blood cells and lack anti-A and anti-B antibodies in their plasma. This allows them to receive blood from any group (A, B, AB, or O) without antibody reaction, making them universal recipients. Group O individuals are universal donors, not recipients.

Malaria is caused by Plasmodium parasites that infect and destroy red blood cells. The spleen works overtime to filter out these infected cells, leading to splenomegaly (enlarged spleen), which is a classic diagnostic feature of malaria.

Smallpox is caused by the Variola virus, making it a viral disease. Tuberculosis is caused by bacteria (Mycobacterium), malaria by protozoa (Plasmodium), and cholera by bacteria (Vibrio cholerae).

The medulla oblongata is the lowest part of the brainstem, connecting the brain to the spinal cord. It controls vital autonomic functions like breathing, heart rate, and blood pressure.

Myopia (nearsightedness) occurs when the eyeball is too long or the cornea is too curved, causing light to focus in front of the retina. This vision defect specifically affects the eyes.