Chapter 5 Flashcards
What is included in the integumentary system?
skin, nails, hair, sweat glands, and oil glands
What are the other two names for the integumentary system?
cutaneous membrane and integument
What are the five functions of the skin?
protect the body from invasion, regulate body temperature, serves as a sensory receptor for sensations, provides for elimination of body wastes in the form of perspiration, responsible for the first step in the synthesis of vitamin D
what are the layers of the skin?
the epidermis, dermis, and subcutaneous layer
what does the epidermis consist of?
squamous epithelial cells, two layers discussed in the chapter-stratum basal and status corneum, melanocytes, keratin
what is the deepest layer of the epidermis called and what does it do and consist of?
the basal layer (stratum basal)- where new cells are created pushing the older cells out; contains melanocytes
what do melanocytes do?
they provide color to the skin and some protection from ultraviolet rays
what is the outermost layer of the epidermis and what does it do and what can be found there?
stratum corneum-where the dead skin cells are constantly being shed and replaced; the pushed out cells die and become filled with a hard protein called keratin
What does keratin do?
it waterproofs the body and creates a barrier that is the first line of defense for the body.
What is the second layer of the skin?
the dermis or corium
What does is its role and what is found in the dermis?
it protects the body against mechanical injury and compression and serves as a reservoir for water and electrolytes; it is composed of living tissue and contains capillaries, lymphatic channels, nerve endings, hair follicles, sweat glands, sebaceous (oil) glands, connective tissue, and elastic fibers; also papillae (projections) originate from this layer (dermal papillae)
what are linear tears in the dermis known as?
stretch marks or stria
What is the third layer called?
the subcutaneous tissue
what does the subcutaneous tissue consist of?
loose connective tissue, adipose (fatty) tissue, nerves, nerve endings, major blood vessels, and extensions of the sweat glands and hair roots
What is a strand of hair made up of?
long slender filament of keratin which consists of a hair root, which is embedded in the hair follicle, and a hair shaft
where does hair develop?
in the hair follicle, forming from keratin cells located at the bottom of the follicles
what is lanugo?
a soft downy hair that covers a fetus toward the end of the second trimester. It disappears shortly after birth.
what gives hair its color?
melanocytes
what are melanocytes?
darkly pigmented cells that produce melanin
what causes red hair?
a uniques type of melanin with iron
what causes white hair?
a decrease in melanin
What are the five listed components of the nail?
the nail body, the cuticle, the lunula, the free edge, and the nail bed
what nourishes the nail body?
the nail body which is epithelial layer and a rich supple of blood vessels
what glands are found the skin?
the sebaceous gland (oil), the sudoriferous glands, and ceruminous gland