What are things we can learn from examining hair? Three parts of hair?

The hair is an outgrowth or appendage that grows from a hair follicle.

Explanation:

The three parts of the hair are cuticle, cortex, and medulla. The cuticle is the hard part made up of scales with keratin protein, cortex is the inner pigmented part, and the medulla is the innermost part of the hair.

During hair examination the type of cuticular scales helps in determining the organism to which it belongs, diameter of the medulla also helps in determining the organism, the DNA analysis of the hair can link to its origin, the detection of heavy metal poisoning like lead, arsenic, and others. Drug abuse details can also be determined by the hair analysis.

the electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, x-rays, and gamma-rays.

a motor homunculus represents a map of brain areas dedicated to motor processing for different anatomical divisions of the body.

homunculus represents the importance of various parts of your body as seen by your brain. as a result, they take up a lot of brain space. although the cortical homunculus is a curiosity, penfield's work in mapping the brain's relationship to the body was invaluable.