Skin Flashcards
What Is The Epidermis?
Superficial layer composed of stratified squamous epithelium.
What Is The Dermis?
Deep layer composed of connective pūtautau and containing blood vessels, lymph vessels and nerves.
What’s In The Skin Appendages?
Hair follicles & hair
Sweat glands
Oil (sebaceous) glands
Nails
Which type of epidermal cell, is the most abundant type in the epidermis?
Melanocytes are dispersed only throughout the deepest layer of the epidermis.
Keratinocytes Job?
Produce keratin, a fibrous protein which toughens the skin and makes it waterproof
Where are Keratinocytes found?
Keratinocytes are found in ALL epidermal layers and are continuously generated and replaced.
Where are Melanocytes found
Found in the stratum basale of the epidermis
What’s The Job of The Melanocytes?
Produce melanin which is a pigment taken up by keratinocytes to provide them protection from UV rays
Langerhans cells job
They ingest foreign material and activate the immune system as necessary.
Where Are Merkel Cells/Disks Found?
These are specialized cells found occasionally in the stratum basale.
What Do Merkel Cells/Disks Do?
They respond to light touch and are associated with sensory nerve endings within the dermis below
What is the epidermal layer found on the thickest skin (eg hands and soles of feet) ?
Stratum lucidum
In the thickest skin, found on the palms of the hands and soles of the feet, there is a fifth epidermal layer called the stratum lucidum- found between the stratum granulosum and stratum corneum.
What Are The Dermal Papillae?
The dermal papillae are extensions of kiriwai that push up against the stratum basale of te kiritai, causing epidermal ridges which fit in the ‘dips’ between the dermal papillae; therefore the epidermis and dermis meet along a continuously undulating edge.
What Are Dermal Ridges?
The dermal ridges are large mounds of dermal tissue in the fingertips which cause large undulations in the entire epidermis, creating the fingerprints that are typically (though not always) unique to each individual.
Function of Nails ?
Nails are believed to function as ‘tools’ that aid in picking things up and scratching an itch.
Sebaceous (Oil) Glands what are they ?
Sebaceous (oil) glands, the body’s only type of holocrine gland, are distributed throughout te tinana (except in the thickest skin) as outgrowths from hair follicles (see image above). These glands produce and secrete sebum which:
softens & lubricates hair and skin
slows water loss from te kiri
kills some bacteria
Where Are Sweat Glands Found?
Found throughout nearly the entire skin (except the nipples and parts of the external genitalia).
What are the 2 types of sweat glands that secrete sweat?
Apocrine sweat glands
Eccrine Sweat Glands
What are the functions of the skin?
Protection
Blood reservoir
Vitamin D metabolism
Secretion of sweat & oil
Excretion of wastes & excess water & electrolytes (via sweat)
Sensory reception
Thermoregulation
In what strata of the epidermis do melanocytes reside?
Stratum basale
What is the function of Langerhan’s (dendritic) cells
To Provide immune protection Langerhan’s/dendritic cells are an immune based cell that can digest and remove microorganisms or foreign substances from the skin.
What is the most superficial (outermost) layer?
Stratum Corneum
What is the deepest layer?
Stratum Basale
What are dermal papillae?
Mounds of dermal tissue that push up against the epidermis. The dermal papillae create an undulating border between the dermis & epidermis as they push up against the deeper layers of the epidermis.
What is The reticular layer of the dermis is composed of?
Dense Irregular Connective Tissue
The deeper layer of the dermis- the reticular layer- is composed mostly of dense irregular CT which is rich in collagen fibers.
What are dermal ridges?
Large mounds of dermal tissue which form the fingerprints
