Integumentary (Slides 1-19)- Mace Flashcards
The skin is composed of __________ (epithelium) and the _______ (CT)
epidermis and dermis
What are the derivatives of skin?
Hairs, sweat glands, sebaceous glands, ceruminous glands, nails
Is the hypodermis a part of the skin?
NO
The hypodermis is composed of ______ CT & _______ CT
Adipose CT & areolar CT
Can you name the layers of the skin from deep to superficial?
Beautiful skin gets loving care (Deep to superficial)
Basement membrane- Stratum basale, stratum spinosum, stratuem granulosum, stratum lucidum, stratum corenum
The more superficial and top part of the skin as a category is called the _______
epidermis
The layers of the epidermis are?
The ones from beautiful skin gets loving care
The epidermis is composed of what type of epithelium?
Keratinized stratified squamous
The epidermis is composed primairly of what type of cell?
Keratinocytes
What are the living layers of the epidermis?
Stratum basale, stratum spinosum, stratum granulosum
What are the dead keratinocyte layers of the epidermis?
Stratum lucidum and stratum corneum
The dermis consists of what type of tissue?
Dense, irregular CT
What type of cells make up the stratum basale?
Single layer of cuboidal to low columnar cells and attaches to the basement membrane
T/F: the sratum basale contains sensory nerve endings for sensing pain and temperature
True
The stratum basale contains what three cell types?
Keratinocytes, melanocytes, tactile cells
divide to regenerate new cells, replace old cells shed at the surface
Keratinocytes
produce & store melanin in response to UV light, transfer pigment granules into keratinocytes, accumulate around
nucleus of keratinocytes, shield nuclear DNA from UV radiation, responsible for the darker tones of skin
Melanocytes
(Merkel cells) are sensitive to touch, when compressed, release chemicals to stimulate sensory nerve endings
Tactile cells
Daughter cells from stratum basale pushed into this layer to become specialized, non-dividing keratinocytes, some in deepest level still dividing cells
Stratum spinosum
T/F: the sratum spinosum contains sensory nerve endings for sensing pain and temperature
True
Which layer of the epidermis contains Langerhans cells?
Stratum spinosum
– immune cells that help initiate immune response
– responsive to pathogens and epidermal cancer cells
Epidermal dendritic cells (Langerhans cells) that live in the stratum spinosum
Which layer of the epidermis has 3-5 layers of keratinocytes
Stratum granulosum
Which layer of the epidermis is the first layer of keratinzation?
Stratum granulosum
– process where keratinocytes fill with keratin
– causes nucleus and organelles to disintegrate
– fully keratinized cells are dead but structurally sound – process not complete until more superficial layers
First layer of keratinzation
Which layer of the epidermis has 2-3 layers of keratinocytes
Stratum lucidum
This layer of epidermis is only found on the palms and shoes and is referred to as the “clear layer”
Stratum lucidum
Why does the stratum lucidim appear clear? What protein is responsible for this?
• Appears translucent because keratinocytes are filled with a translucent
protein, eleidin (intermediate product in keratin maturation)
Which layer of skin is the horn-like layer and that does not have a nucleus?
Stratum corneum
Which layer of the epidermis is anucleate
Stratum corneum
What layer of the epidermis is this talking about?
• Migration of of keratinocytes to stratum corneum takes 2 weeks, the cells remain in stratum corneum another two weeks, then shed
• Surface unsuitable for the growth of many microorganisms
– secretions of exocrine glands also helping prevent growth
Stratum corneum
Which type of skin is on the palms of hands, soles of feet, surfaces of fingers, toes
Thick skin
Which layer of skin as all five epidermal strata
Thick skin
Which layer of skin has sweat glands, but no hair follicles or sebaceous glands
Thick skin
This skin is 0.4 to 0.6 mm thick
Thick skin
This layer of skin lacks a stratum lucidum
Thin skin
This type of skin has sweat glands, hair follicles, and sebaceous glands
Thin skin
This type of skin is from 0.075 to 0.150 mm thick
Think skin
Where do we get the red tint in our skin from?
- Reddish tint due to the presence of hemoglobin in blood vessels in dermis
- Hemoglobin is an oxygen binding compound present in red blood cells
- More visible if blood vessels dilate (vasodilation)
Where do we get the tan tint in our skin from?
- black, brown, tan, yellow-brown shades
- Pigment produced and stored in melanocytes, transferred to keratinocytes of stratum basale
- Amount in skin varies according to heredity and light exposure (UV light stimulates production of melanin)
- All people with same number of melanocytes
- Activity and color varying among individuals, darker skinned people produce more and darker colored melanin
Describe the mechanism of a sun tan
- UV light damages the DNA in a keratinocyte
- Damaged cell stimulates p53
- p53 produced PCOM
- PCOM produces alpha-MSH and B-endorphins
* *beta endorphins make us feel good in the sun - alpha MSH stimulates MC1R on the melanocyte
- Liberation of cAMP
- cAMP goes into DNA and stimulates MITF (melanin inducing factor)
- Result = increased pigment production
