-The shaft of a hair consists of a cuticle and a cortex of hard-keratin surrounding, in many hairs, a soft-keratin medulla

-The root of a hair is situated in the hair follicle, sunken into either the dermis or the subcutaneous tissue. 

- Without them, we'd have a hard time scratching an itch or untying a knot.

-The skin below the nail is the matrix. The larger part of the nail, the nail plate, looks pink because of the network of tiny blood vessels in the underlying dermis. The whitish crescent-shaped area at the base of the nail is the lunula.

-The immune cells live in the skin and help provide defense against infections.

-The integumentary system works with the digestive system to encourage the uptake of calcium in our diet.

-The Integumentary system surfaces capillaries through your body. Capillaries near the surface of the skin open when your body needs to cool off and close when you need to conserve heat.

-It also protects the body's internal tissues and organs

-Located under the Epidermis and above the Subcutaneous layer.

-Provides strength and flexibility to the skin. 

-Comprised of two layers: the papillary dermis and the reticular dermis.

-The dermis has connective tissue, blood vessels, oil and sweat glands, nerves, hair follicles, and other structures.

-Also called Corium

-This complexity allows you to be aware of your surroundings and take appropriate actions.

-The five types sensory detectors are:

Chemoreceptors which detects the presence of chemicals.

Thermoreceptors detect changes in temperature.

Mechanoreceptors detect mechanical forces.

Photoreceptors detect light during vision.

-More specific examples of sensory receptors are baroreceptors, propioceptors, hygroreceptors, and osmoreceptors.

-Sensory receptors perform countless functions in our bodies mediating vision, hearing, taste, touch, and more.

-There are two types of glands. The Endocrine gland and the Adrenal glands. 

-The Endocrine are ductless glands and release the substances that they make (hormones) directly into the bloodstream. 

-The adrenal glands are small structures attached to the top of each kidney. The body has two adrenal glands that release chemicals called hormones into the bloodstream. These hormones affect many parts of the human body.

-The epidermis includes five main layers: the stratum corneum, stratum lucidium, stratum granulosum, stratum spinosum, and stratum germinativum.

-Contains connective tissue, hair follicles and sweat glands.

-The function of it is to protect your skin and create your skin tone. It also helps regulate body temperature.