What are the 4 distinct cell types found in the epidermis?
- Langerhans cells ( denditic)
- Merkel Cells (tactile)
What are the layers of the epidermis?
- Stratum Basale
- Stratum Spinosum
- Stratum Granulosum
- Stratum Lucidum
- Stratum Corneum
AKA: Stratum Germinativum, what skin layer of the epidermis is attached to the underlying dermis, is cell producing consisting of one layer of keratinocytes?
- Stratum Basale
- (deepest layer of the epidermis)
Know as the prickly layer of the epidermis due to desmosomes holding tightly to shrinking keratinocytes, Langerhans cells are most abundant in this layer.
- Stratum Spinosum
- 4-6 cell layers
The strongest and toughest layer of the epidermis contains keratohyaline and lamellar granules. Cell death begins in this layer due to keratinization.
- Stratum Granulosum (Granular layer)
- 3-5 cell layers
What layer of the epidermis is a translucent band consisting of a few rows of dead keratinocytes and is found only in thick skin?
- Stratum Lucidum
- Clear layer
The outer layer of the epidermis, aka the horny layer offers protection preventing abrasion and penetration due to keratin and is also nearly water proof?
- Strautam Corneum
- 30 cell layers thick 3/4 epidermal thickness
This cell makes up 90% of the epidermal cells it is found in the stratum basale and produces keratin. These cells undergo constant mitosis.
What is the cell that makes up 10-25% of the stratum basale, produces melanin and forms a pigment protecting shield for the keratinocytes?
This cell arises from bone marrow and migrates to the epidermis. It arms the immune system by introducing antigens and is most abundant in the stratum spinosum layer of the epidermis.
- Langerhan's cell
- AKA: Dendritic Cell
what cell is a sensory receptor and found at the epidermal and dermal junction?
- Merkel Cells
- AkA: tactile cells
A dark pigment that determines skin and hair color, formed by cells called melanocytes.
fibrous protein found in skin, hair and nails, protects and water proofs.
when a cell begins to fill with keartin and cell death occurs this is called
this process begins in the stratum granulosum layer
Keratinocytes accumulate two different granules in the stratum granulosum layer, which one helps to form keratin in the upper layers?
keratinocytes accumulate two types of granules in the stratum granulosum layer which granule contains a water resistant glycolipid that fills extracellular spaces and slows H2O loss?
- Lamellar Granules
A layer of CT that is mostly adipose tissue, considered the superficial fascia. stores fat reducing heat loss, anchors the skin to the underlying structures and acts as a shock absorber.
- Subcutaneous Tissue ( hypodermis)
- NOT A LAYER OF SKIN
- Accumulates n the breast and thighs of women and anterior abdomen men.
What region of the skin contains the two sublayers: Papillary layer and Recticular layer, it is made mostly of dense irregular CT and is vascularized apart from containing blood vessels it also contains nerves and nerve endings, glands and hair follicles?
What sub layer of the dermis is areolar CT and is located just below the epidermis and contains dermal papillae that protrudes into the epidermis?
What sub layer of the dermis is made up of dense irregular CT and makes up 80% of dermal thickness; this layer receives its nourishment from the cutaneous plexus which lies between this layer and the hypodermis.
What are the lines that occur at or near joints where the dermis is closely attached to the underlying fascia?
What are the invisible lines that represent separations between collagen? They run circular around the trunk and longitudinally around the head and libs
- Cleavage Lines
- These lines are important to surgeons because when an incision is made parallel to to these lines, the skin gapes less and heals more readily
What are forms of Chemical Barriers?
- Acid Mantle (mixture of sweat and sebum)
- Melanin provides a chemical pigment shield to prevent UV damage to skin cells
A chemical barrier that is a mixture of sweat and sebum on the surface of the skin is called what?
Skin is our barrier, what are forms of protection that it offers?
- Chemical Barriers
- Physical Barriers
- Biological Barriers
What is the oily fluid secreted by the sebaceous glands that lubricates and softens the hair and skin, prevents hair from becoming brittle, slows water loss from skin when humidity is low and is bacterium killing?
What gland is found throughout the body with an exception of thick skin areas, secrets sebum and secretion is stimulated by hormones?
Sebaceous Glands (oil)
What gland is distributed over the entire body except nipples and parts of external genitalia? There are two types of this gland: Eccrine and Apocrine
Sudoriferous Glands (Sweat)
The sweat gland that produces true sweat and is the most numerous of sweat glands is know as what?
- Eccrine (merocrine) Glands
- aid in thermoregulation
what system regulates sweating and its major role is to prevent the body from over heating?
Autonomic nervous system ANS
The sweat gland that is confined to the axillary and anogenital areas within the hypodermis is know as what? They produce true sweat along with fatty substances and proteins and increase function during stress, sexual foreplay and menstrual cycles.
The modified aprocrine that is found in the external auditory canal and produces cerumin (ear wax) is known as what?
The modified aprocrine gland that secretes milk for nutrition for newborns is know as what?
What are the 3 layers of keratinized cells found in hair?
- medulla-inner core
- cortex-middle layer
- cuticle-outer layer
Structure of the hair that projects from the skin is known as what? (Keratinization is complete)
Structure of the hair that is embedded in the skin is known as what? (keratinization is ongoing)
Structure of the hair that is pouches of epidermis is known as what? This structure is located everywhere except palms,soles,lips,nipples and genitals.
deep end of the hair follicle, located within the dermis is know as what?
A knot of sensory nerve endings that wrap around each hair is know as what?
hair follicle receptor (root hair plexus)
what is the arrector pili muscle?
- bundle of smooth muscles
- produces goose bumps
- (raiser of hair)
Fine, delicate hairs of a fetus is known as what?
fine body hairs of children and adult women are know as what?
coarser hairs of eyebrows, scalp and pubic regions are known as what?
What 3 pigments contribute to skin color?
- melanin-made in the skin
A partial thickness burn that injures only the superficial epidermis with no blister formation or scarring is what type of burn?
1st degree burn
A partial thickness burn that injures the epidermis and some portion of the dermis and results in blister formation is what type of burn?
2nd degree burn
full thickness burn that injures the epidermis,dermis and hypodermis and results in no pain due to damaged nerve endings is what type of burn?
3rd degree burn
What is the immediate threat of burns and when does infection become a threat?
dehydration and electrolyte imbalance due to loss of fluids
Infection becomes a threat after 24 hours