Ch 4- Integumentary System Flashcards
The cutaneous membrane of the skin is made up of what?
The epidermis and dermis
The dermis is made up of what layers?
Papillary layer and reticular layer
What are the accessory structures of the skin?
Hair follicles, exocrine glands, nails
What kind of epithelium makes up the epidermis?
Stratified squamous epithelium
What are the four cell types found in the epidermis?
Keratinocytes, melanocytes, merkel cells, and langerhan cells
What are the five layers of the epidermis?
Stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum
Which layer of the epidermis is only found in thick skin?
Stratum lucidum
Where is thick skin found?
On the surfaces of the palms and soles of feet
What are epidermal ridges?
Fingerprints
What forms the epidermal ridges?
The dermal papilla in the dermis
What kind of structures form through invagination or unfolding of the epidermis (during embryonic development)?
Accessory structures
What are epithelial cells that surround the papilla?
Hair bulb
Surrounded by epithelium and contains capillaries and nerves
Hair papilla
The inner medulla of the hair is?
Soft and flexible keratin
The outer cortex of the hair is?
Hard keratin - stiff
Dead, keratinized cells that coats the hair is?
Cuticle
Surrounds the hair root and the deeper portion of the shaft. Cells here die quickly and this layer does not extend the entire length of the hair follicle
Internal root sheath
Extends from the skin surface to the hair matrix
External root sheath
A thickened, clear layer wrapped in the dense connective tissue sheath of the follicle as a whole
Glassy membrane
What are the functions of exocrine glands?
Assist in thermoregulation, excrete wastes, and lubricate epidermis
What are the two types of exocrine glands?
Sebaceous and sweat glands
Secretes oily lipid(sebum) that coats hair shaft and epidermis, provides lubrication and antibacterial action
Sebaceous glands
Produces watery solution by merocrine secretion, flushes epidermal surface, and performs other special functions
Sweat glands
Secretes into hair follicles
Typical sebaceous glands
Secretes onto skin surface
Sebaceous follicles
Widespread, produces thin secretions, mostly water. Controlled by nervous system and important for thermoregulation and excretion. Some antibacterial action occurs.
Merocrine sweat glands
Produces viscous secretion of complex composition, strongly influenced by hormones, further subdivided into two glands
Apocrine sweat glands
Secretes waxy cerumen into external ear canal
Ceruminous glands
Apocrine glands specialized for milk production
Mammary glands
Covers the nail bed
Nail body
Pale crescent shape on nail
Lunula
