Thick Skin
What are Keratinocytes?
The body's most abundant epithelial cells, they dominant the epidermis.
Along with hair follicles, sebaceous and sweat glands, and nails, hair is considered what type of structure?
A accessory to the integument
What do the nails protect?
Protect the exposed dorsal surfaces of the tips of the fingers and toes
What are Sebaceous glands?
oil glands, are holocrine glands that discharge an oily lipid secretion into hair follicles
If basal cell divisions replace lost epidermal cells, what replaces lost dermal cells?
mesenchymal cells
What are the five layers of thick skin?
Stratum Basale, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, Stratum Corneum
How much hair is on your head and what is the function?
500,000
to protect your scalp from the ultraviolet rays, help cushion light impacts to the head, and insulate the skull
The nail body is recessed deep to the level of the surrounding epithelium and is bordered on either side by of what?
Lateral nail grooves and Lateral nail folds
What type of gland is coiled and produces a sticky, cloudy, and potentially odorous secretion?
Apocrine Sweat Glands
What kind of damaged blood vessels also begin to divide, and capillaries follow the fibroblasts, enhancing circulation?
Endothelial cells
What is the deepest layer of the epidermis?
Stratum Basale
What are the names of problems or scenarios where people's nails turn yellow?
respiratory disorders, thyroid gland disorders, or AIDS.
Where do sebaceous glands and sebaceous follicles discharge their secretions?
A sebaceous gland discharges its secretion into a hair follicle. A sebaceous follicle discharges its secretion directly onto the epidermis.
The combination of blood clot, fibroblasts, and an extensive capillary network at the base of a wound is called what?
granulation tissue
If the elastic fibers provide flexibility, why do the collagen fibers limit that flexibility?
To prevent damage to the tissue
Describe a typical strand of hair.
A typical hair strand is a keratinous strand produced by epithelial cells of the hair follicle
What substance makes fingernails hard?
Keratin
What type of gland that is very active during the last few months of fetal development?
Sebaceous glands
Why are older people more prone to skin injury, tears, and infections?
the connections between the epidermis and the dermis have grown weak
Describe the location of the dermis.
The dermis layer is located between the epidermis and the subcutaneous layer
What happens when the arrector pili muscle contracts?
The contraction of the arrector pili muscle pulls the hair follicle erect. The result is known as “goose bumps.”
What term is used to describe the thickened stratum corneum underlying the free edge of a nail?
hyponychium.
What are the two types of sweat glands?
apocrine sweat glands and eccrine sweat glands
Why do hair follicles stop functioning or produce thinner, finer hairs and turn these hairs are gray or white?
Decreased melanocyte activity