Tag: science & technology

The cerebrum is the largest part of the human brain, making up about 80% of its mass. It handles higher cognitive functions like thinking, language, and sensory processing, unlike the smaller cerebellum or medulla.

Bones and teeth are primarily composed of calcium phosphate in the form of hydroxyapatite. This mineral compound provides structural rigidity, unlike calcium carbonate (shells), calcium sulfate, or calcium nitrate.

Hemoglobin's key component is iron, which enables it to bind and transport oxygen. Each hemoglobin molecule contains four iron atoms that give blood its red color and allow efficient oxygen delivery throughout the body.

Kidneys filter blood and remove metabolic wastes like urea, creatinine, and excess salts through urine formation. While kidneys also help regulate blood pressure via the renin-angiotensin system, waste removal is their primary function. Body temperature is regulated by the hypothalamus and sweat glands in the skin, not kidneys.

Hemoglobin is a protein in red blood cells that binds oxygen in the lungs and transports it to body tissues. It gives blood its red color and is essential for aerobic respiration. Hemoglobin does not destroy bacteria (that's white blood cells), prevent anemia (it actually causes anemia when deficient), or directly utilize energy.

Lachrymal glands, also called lacrimal glands, are located above each eye and secrete tears to lubricate and protect the eyes. The pituitary is the master gland regulating hormones, thyroid regulates metabolism, and pancreas produces digestive enzymes and insulin - none produce tears.

The liver is the largest internal gland and largest internal organ in the human body, weighing about 1.5 kg. It performs vital functions including detoxification, protein synthesis, and bile production. The thyroid and pancreas are much smaller endocrine glands.

The skin is the largest organ in the human body, covering about 2 square meters in adults and comprising about 16% of body weight. It provides protection, temperature regulation, and sensation. Liver, heart, and kidneys are internal organs but are much smaller than skin.

Blood group O individuals lack A and B antigens on their red blood cells, making their blood compatible with all other blood types during transfusion. O negative (lacking Rh factor) is the true universal donor. AB has both antigens, A has only A antigen, B has only B antigen.