Integumentary System Test Flashcards
Of what are the organs of the integumentary system made?
cutaneous membranes
Give the name and location of the four different kinds of membranes.
- Serous membranes: line body cavities that don’t open to the outside; secrete serous fluid
- Mucous membranes: line cavities and tubes opening to the outside; secrete mucus
- Synovial membranes: line joint cavities; secrete synovial fluid
- Cutaneous membranes: cover the body as skin
What is the largest organ by weight?
the skin
Name the major functions of the integumentary system.
- Protects the body from invading microorganisms (unless the skin is broken)
- Prevents water loss from the body
- Helps to regulate body temperature
- Important in the synthesis of vitamin D
- Has sensory receptors for touch, pain, pressure, and temperature
- Excretes small quantities of wastes
The integumentary system is composed of two distinct tissue layers. Name and describe them.
- Epidermis: the outermost layer of the skin; composed of stratified squamous epithelial tissue; avascular (has no blood vessels)
- Dermis: the innermost layer of the skin; composed of connective tissue (collagen, elastin, adipose, blood) smooth muscle tissue, and nervous tissue
How does the function of the epidermis differ from that of the dermis?
The epidermis protects the body, and the dermis nourishes the epidermis with its blood vessels.
What are the accessory structures of the integumentary system or skin?
- hair follicles
- nails
- sweat glands (eccrine and apocrine)
- sebaceous glands
Where is the subcutaneous layer found? Is it a part of the skin?
The subcutaneous layer is located below the dermis. Another name for it is hypodermis. The subcutaneous layer is not considered to be a part of the skin
What is the function of the subcutaneous layer?
- Insulates the body since it is composed of adipose tissue (fat)
- Adheres the dermis to the muscular layer
What are characteristics of the epidermis?
- Composed of stratified squamous epithelium
- Has no blood vessels (is avascular)
- Its outer layers become keratinized (hardened) and “slough” or fall off
- Its innermost layer of cells rests on a basement membrane
- It is thickest on the palms of the hands and soles of the feet
What are the layers (strata) of the epidermis, from the outside to the inside?
- Stratum corneum–outermost, keratinized part of the epidermis
- Stratum lucidum–appears as a clear layer on the palms and the soles
- Stratum granulosum–cells underneath the stratum lucidum
- Stratum spinosa–cells located within dermal papillae
- Stratum basale–layer of cells attached to the basement membrane; contains melanin-containing cells called melanocytes
Why is the boundary between the epidermis and the dermis uneven?
The epidermis has ridges. The dermis has dermal papillae which extend up into the spaces between epidermal ridges, carrying blood vessels to nourish the epidermis. This unevenness leads to unique fingerprints for individuals.
What are the characteristics of the dermis?
- Contains the accessory structures of the skin: hair follicles, nail, sweat glands, and sebaceous glands
- Has blood vessels
- Binds the epidermis to underlying tissue (the subcutaneous layer)
- Has fibrous connective tissue (collagen and elastin) which provide resilience and elasticity
- Has smooth muscle fibers attached to hair follicles; when they contract they cause your hair to stand on end
- Has nerve fibers
- Has sensory receptors like Meissner’s corpuscles and Pacinian corpuscles
Can severely burned or injured dermis tissue always regenerate?
No. If accessory structures (hair follicles, nails sebaceous glands, sweat glands) do not survive, then dermis cannot regenerate. If accessory structures survive, the dermis can regenerate
What is the meaning of these terms associated with hair: hair follicle, hair root, hair shaft, hair papillae, and arrector pili muscle?
- Hair root–portion of the hair from the scalp down
- Hair follicle–tube-like depression of epidermal cells extending down into the dermis; completely surrounds the root of the hair and the hair papillae
- Hair shaft–portion of the hair from the scalp up
- Hair papillae–projection of connective tissue extending up into the hair follicle; enable blood vessels to get to rapidly growing cells in the hair root and nourish them
- Arrector pili muscle–smooth muscle associated with the hair follicle; when it contracts it causes “goose bumps” and hair to stand on end