NATS 1610 Lecture Notes - Lecture 4: Arrector Pili Muscle, Basal Lamina, Goose Bumps
26 Jan 2017
School
Department
Course
Professor
Document Summary
Glands, which are one of the accessory organs of the skin, came from the epidermis. Hair: it"s a structure that exible and made of mostly keratinized cells. It is made up of a root that is embedded int the dermis, and a shaft that extends out of the epidermis. There is also an epidermis that surrounds the hair inside the dermis layer, and that is called a follicle. That is why when you pull a hair out it hurts. Arrector pili muscles: are smooth muscle, which is involuntary, and they are attached to hair follicles, contraction causes the hair to stand and form goose bumps. The way that hair grows works the same way that the structure of the epidermis does. Hair is basically bunches of dead keratinocytes that come together to form shingle like layers. The difference between naturally curly and straight hair is the way these keratinocytes arrange into shingles.
