Integumentary System Flashcards
- contains cutaneous sensory receptors
- aids in the production of vitamin D
- is important in regulating body temperature
- plays a minor role in excretion and absorption.
- a protective barrier for the body
Functions of the Integumentary System
the outer layer of the skin, is composed of epithelial tissue
Epidermis
the connective tissue layer that is firmly attached to the epidermis by a basement membrane, provides the avascular epidermis with nutrients, and connects the epidermis to the underlying hypodermis.
Dermis
is a major storage site for adipose tissue.
Hypodermis
keratinized stratified squamous epithelium.
The epidermis is
contains 8 to 10 rows of cells, mainly keratinocytes
The stratum spinosum (spinos- = thorn-like)
This layer contains 3 to 5 rows of flattened keratinocytes that are beginning to die
The stratum granulosum (granulos- = little grains).
This layer is translucent in specimens of fresh skin, but in prepared slides it may be clear or stained. Contains 3 to 5 rows of flat, dead keratinocytes.
The stratum lucidum (lucid- = clear)
This layer is tough and water-repellent. These cells continually slough off and are replaced by cells in the adjacent layer. Is a very thick layer containing 25 to 30 or more rows of dead, squamous-shaped keratinocytes.
the stratum corneum (corn- = hard or hoof-like)
Is found on the palms of the hands and the soles of the feet and has all five strata
Thick skin
Covers the rest of the body, does not have a visible stratum lucidum and has a thinner stratum corneum than thick skin.
Thin skin
A thin layer of areolar connective tissue that is deep to the stratum basale of the epidermis and the basement membrane.
The papillary region
Finger-like projections of the papillary region that extend into the epidermis. In the palms, fingers, soles, and toes, the dermal papillae cause genetically determined whorls in the epidermis called epidermal ridges that increase surface area, friction, and grip. Sweat glands deposit their secretions onto these ridges, resulting in fingerprints when these ridges touch surfaces.
Dermal papillae
The deeper and much thicker region of the dermis. It is composed mainly of dense, irregular connective tissue whose collagen fibers provide the skin with strength and whose elastic fibers provide elasticity.
The reticular layer
or sweat glands, secrete a watery substance that is important in excretion and body temperature regulation.
Sudoriferous glands (sudori- = sweat; -ferous = bearing),
The most common type of sudoriferous gland and are found on most areas of the body. Ducts from the these glands deposit their secretions, called sweat, on the epithelial surface.
Eccrine glands (eccrine = sweating outwardly)
Found only in the axilla, genital area, and pigmented area around the nipples (areolae). These glands produce a secretion similar in composition to sweat but more viscous. This secretion, which is deposited on the distal end of the hair root, is odorless until broken down by bacteria.
Apocrine glands
Found in the ear canal and secrete a waxy substance called cerumen that prevents foreign substances (including insects) from entering the auditory canal
Ceruminous glands (ceri- = wax)
Found in the breasts and synthesize and secrete milk after appropriate hormonal stimulation.
Mammary glands
These glands or oil glands, are found surrounding hair follicles and deposit sebum, an oily substance that lubricates the skin and hair, into the neck of the follicle.
Sebaceous glands (sebace- = greasy)
Found all over the body with the exception of the palms, soles, lips, and parts of the external genitalia. It consists of dead, keratinized epithelial cells and has two main sections
Hairs
Projects from the skin surface
The shaft
Extends into the dermis of the skin and sometimes the hypodermis.
The root
Surrounds the hair root, is formed from epidermal layers that project into the dermis.
The hair follicle
The expanded base of the hair follicle, contains the papilla of the hair and the matrix.
The hair bulb
A projection of connective tissue into the hair follicle and contains blood vessels that provide nutrients to the dividing cells of the matrix.
The papilla
Is derived from the stratum basale of the epidermis, forms new hair cells that are added to the base of the hair root.
The matrix
Is comprised of dermal tissue surrounding the hair follicle
A connective tissue sheath
A bundle of smooth muscle cells attached to the connective tissue sheath around the hair follicle.
The arrector pili (arrect- = to raise; pili = hair)
The layer of hair that we see, is a thin layer of dead, flattened, keratinized cells that overlap each other like shingles on a roof.
The cuticle
Cells in the…….. contain pigment granules that give hair its color.
cortex and medulla
Are found on the distal ends of the digits, assist in grabbing and manipulating objects, and protect the digits
Nails
The part of the nail that is visible
The nail body
Extends beyond the digit,
The free edge
Within the fold of skin at the proximal end of the nail body
The root
The crescent-shaped area of the nail body distal to the nail roo
The lunula (lunula = little moon)
The thickened epithelial tissue along the proximal border of the nail body.
The cuticle or eponychium (epi- = above; -onych = nail)
is deep to the free edge and attaches the nail to the fingertip
The hyponychium (hypo- = below) or nail bed
The epithelial tissue deep to the nail root that divides to produce new cells that are added to the nail body as it grows.
The nail matrix
