Medical Science and Human Biology

The normal resting heart rate for adults ranges from 60-100 beats per minute, with 72 bpm being the commonly cited average. This rate represents the heart's efficiency in pumping blood at rest.

AB positive blood type individuals are universal recipients because they have both A and B antigens and no anti-A or anti-B antibodies. This allows them to receive blood from any ABO group without adverse reactions.

Malaria, caused by Plasmodium parasites transmitted by mosquitoes, primarily affects the spleen. The parasite infects and multiplies within red blood cells, causing their destruction and leading to splenomegaly (enlarged spleen) as the organ works to filter damaged cells.

Smallpox is caused by the variola virus, making it a viral disease. The other options are bacterial (tuberculosis, cholera) or parasitic (malaria) in origin, which are caused by different pathogens requiring different treatments.

The medulla oblongata is located at the base of the brainstem and is a vital part of the brain. It controls essential autonomic functions like breathing, heart rate, and blood pressure, making it crucial for survival.

Myopia, or nearsightedness, is an eye condition where distant objects appear blurry while close objects remain clear. This occurs when the eyeball is too long or the cornea is too curved, causing light to focus in front of the retina instead of on it.

Leukemia is a cancer of blood-forming tissues, primarily the bone marrow and lymphatic system. It causes the production of abnormal white blood cells that crowd out healthy blood cells, leading to infections, anemia, and bleeding problems.

Myopia (short-sightedness) is corrected using concave lenses, which diverge light rays before they enter the eye. This compensates for the eye's excessive focusing power, allowing light to focus correctly on the retina for distant vision.

Trachoma is a contagious bacterial eye infection caused by Chlamydia trachomatis. It's one of the leading causes of preventable blindness worldwide and affects the conjunctiva and eyelids, potentially leading to eyelid deformities and corneal damage.

Typhoid (caused by Salmonella Typhi) and cholera (caused by Vibrio cholerae) are both transmitted primarily through contaminated water and food. These water-borne diseases spread when water sources are contaminated with fecal matter containing the pathogens.

Pyorrhea, also called periodontitis, is an inflammatory disease affecting the gums and supporting structures of teeth. It causes gum infection, inflammation, and can lead to tooth loss if untreated. The other options are unrelated to this dental condition.

Diabetes mellitus occurs when the pancreas produces insufficient insulin or the body cannot effectively use insulin. Insulin regulates blood sugar levels, and its absence causes glucose to accumulate in the bloodstream. Sugar, calcium, and vitamins are not the primary deficiency causing diabetes.

The appendix is a small, finger-like pouch attached to the cecum, which is the beginning of the large intestine. It is not part of the small intestine, stomach, or liver. The large intestine absorbs water and forms stool, with the appendix being a vestigial structure at its start.

Bronchitis is inflammation of the bronchial tubes that carry air to and from the lungs. It specifically affects the respiratory tract, causing coughing and mucus production. Blood, bladder, and liver are unrelated to this respiratory condition.

ECG (electrocardiogram) records the heart's electrical activity to diagnose cardiac conditions like arrhythmias, heart attacks, and heart muscle damage. It does not assess brain, kidneys, or lungs - each has its own diagnostic tests like EEG, renal function tests, and spirometry.

Biopsy involves removing and examining tissue from a living body to diagnose disease. It is performed on living patients to detect cancer, infections, or other conditions. Post-mortem tissue examination is called an autopsy, not biopsy, and blood samples are not biopsies.

Barium is a contrast agent used in X-rays of the alimentary canal (digestive tract) to visualize the esophagus, stomach, and intestines. The patient drinks barium sulfate, which coats the digestive lining and appears white on X-rays. It is not used for blood grouping or brain X-rays.

Dialysis artificially filters blood when kidneys fail, removing waste products and excess fluids that healthy kidneys would eliminate. It is a life-sustaining treatment for kidney failure. Dialysis does not treat heart, brain, or stomach conditions - each requires different medical interventions.

Lock jaw (trismus) is a characteristic symptom of tetanus, caused by toxins produced by Clostridium tetani bacteria. These toxins cause severe muscle spasms, particularly in the jaw and neck muscles. Cholera, plague, and diphtheria do not cause this specific jaw symptom.