Human Body Facts Quiz

Iridology is the study and analysis of the iris of the eye for diagnostic purposes. Practitioners claim that patterns, colors, and other characteristics of the iris can be examined to determine information about a patient's systemic health, though it is considered pseudoscience by mainstream medicine.

The human eyeball weighs approximately 28 grams on average, though measurements vary slightly by source and individual factors. Standard anatomical references typically cite 7-8 grams (about 28 grams total when accounting for orbital tissues and contents), making option A the most accurate among the given choices.

The cornea is the only avascular (without blood vessels) tissue in the human body. It must be transparent to allow light to pass through to the retina. Blood vessels would scatter light and impair vision.

The stapes (one of the three ossicles in the middle ear) is the smallest bone in the human body, measuring about 3mm. It transmits sound vibrations from the incus to the inner ear.

The human face is made up of 14 bones: 2 nasal, 2 maxillae, 2 zygomatic, 2 lacrimal, 2 palatine, 2 inferior nasal conchae, 1 mandible, 1 vomer. Note: 'face bones' doesn't include the cranium.

Enamel, the outermost layer of teeth, is the hardest substance in the human body. It's even harder than bone and protects the softer dentin and pulp underneath. Note: 'teeth' is not a specific tissue.

The average human head weighs approximately 8 pounds (3.6-4 kg), which includes the skull, brain, and other tissues. This is about 7-8% of total body weight.

The average human scalp has approximately 100,000 hair follicles, though this varies by individual (blonde: ~140k, brunette: ~110k, redhead: ~90k). Option A is slightly high, while C and D contain formatting errors.