Science and Technology: Measurement and Human Biology

Pyorrhea (periodontitis) is a gum disease that causes inflammation and infection of the tissues surrounding and supporting the teeth. It leads to gum recession, bone loss, and potential tooth loss.

Diabetes mellitus is caused by insufficient insulin production (Type 1) or insulin resistance (Type 2). Insulin is the hormone that regulates blood sugar levels. Without effective insulin action, glucose accumulates in the blood.

The appendix is a small, finger-like pouch attached to the cecum of the large intestine (colon). It is located at the junction of the small intestine and large intestine in the lower right abdomen.

Bronchitis is inflammation of the bronchial tubes, which are the main airways (passages) of the respiratory tract. It causes coughing, mucus production, and breathing difficulties, affecting the lungs' airways.

ECG (Electrocardiogram) records the electrical activity of the heart over time using electrodes placed on the skin. It is the primary diagnostic tool for detecting heart rhythm abnormalities (arrhythmias), heart attacks, heart enlargement, and other cardiac conditions. It does not directly assess brain, kidney, or lung function.

Biopsy is a medical procedure where living tissue is removed from the body for microscopic examination to diagnose diseases, particularly cancer. It must be performed on a living body where cellular architecture and metabolic activity are preserved. Post-mortem tissue analysis is called an autopsy, not a biopsy.

Barium sulfate is a radiopaque contrast medium used in imaging the gastrointestinal tract. When swallowed (barium swallow) or administered as an enema (barium enema), it coats the lining of the alimentary canal (esophagus, stomach, intestines), making these structures clearly visible on X-ray. It helps diagnose ulcers, tumors, obstructions, and other GI abnormalities. It has no use in blood grouping or brain imaging.

Dialysis is an artificial process that performs the kidney's primary function of filtering waste products, excess salts, and fluids from the blood when kidneys fail. It is the definitive treatment for end-stage renal disease and acute kidney failure. The procedure has no therapeutic effect on heart weakness or brain diseases.

Tetanus is caused by Clostridium tetani bacteria which produce a neurotoxin called tetanospasmin. This toxin causes severe muscle spasms and rigidity, classically beginning in the jaw muscles (lockjaw or trismus), making it difficult or impossible to open the mouth. The muscle rigidity then spreads to other parts of the body. Cholera causes watery diarrhea, plague causes swollen lymph nodes and fever, and diphtheria causes throat membrane formation.

Rickets is a childhood bone disorder caused by vitamin D deficiency, calcium deficiency, or phosphate deficiency. It prevents proper mineralization of growing bones, leading to soft, weak bones that can deform easily. It causes bone pain, delayed growth, skeletal deformities (bowed legs), and muscle weakness. Rickets primarily affects the skeletal system, not muscles, blood, or general tissues.

The pulmonary artery is the only artery that carries deoxygenated blood. It transports blood from the right ventricle of the heart to the lungs for oxygenation (pulmonary circulation). After receiving oxygen in the lungs, the blood returns to the heart via the pulmonary veins, which are the only veins carrying oxygenated blood. All other arteries carry oxygenated blood, and all other veins carry deoxygenated blood.

The lungs are located in the thoracic cavity (chest cavity), which is bounded by the ribs, sternum, and vertebral column. The thoracic cavity is separated from the abdominal cavity below by the diaphragm. The pericardial cavity contains only the heart, the buccal cavity is the mouth cavity, and the abdominal cavity contains digestive organs. The thoracic cavity houses both lungs and the heart.

Normal human somatic cells contain 46 chromosomes (23 pairs - one set inherited from each parent). Gametes (sperm and egg cells) contain 23 chromosomes each. 44 chromosomes would indicate a chromosomal abnormality like Turner syndrome, while 48 chromosomes is not a normal human karyotype.

Enzymes are biological catalysts that speed up chemical reactions. While enzymes ARE involved in all processes listed (respiration, digestion, immune system, and reproduction), digestion is the most direct and commonly tested association - enzymes like amylase, protease, lipase break down food molecules.

An ammeter is the instrument specifically designed to measure the strength of electric current in a circuit. Anemometer measures wind speed, barometer measures atmospheric pressure.

An audiometer is the device used to measure the intensity of sound and test hearing acuity. Barometer measures pressure, callipers measure diameter, balometer is not a standard measuring instrument.

A barometer is the scientific instrument used to measure atmospheric pressure. Altimeter measures altitude, anemometer measures wind speed.

Callipers (or calipers) are used to measure the inner and outer diameters of solid objects. Calorimeter measures heat, chronometer measures time, barometer measures pressure.

A chronometer is a precise timekeeping instrument used to determine longitude at sea by comparing local time to a reference time like GMT. Calorimeter measures heat, cryometer measures very low temperatures.