L27: Skin 1 (onaizi) Flashcards
What is the largest organ in the body?
The skin
Why is the skin an organ?
Bc it consists of different tissues that are joined to perform a specific function
What are the skin derivatives?
- sweat glands
- oil glands
- hair
- nails
What are the 3 layers of the skin?
What are the functions of the skin?
1) Protection
2) Maintains body temp
3) Excretion
4) Sensory receptor
5) Vitamin D Synthesis (calciferol)
How does the skin protect the body?
How does the skin maintain body temperature?
What does the skin excrete?
Skin secretes sweat that removes water, salts, uric acid (NaCl, urea) and ammonia from body surface.
How does the skin function as a sensory receptor?
How does the skin synthesize vitamin D?
And what is it necessary for?
Fill in the blanks
Which layer of the skin is stratified squamous keratinized?
Epidermis
Which layer of the skin is dense connective tissue?
Dermis
Which layer of the skin is adipose and loose areolar CT?
Subcutaneous (sub dermis) layer
Describe the epidermis
Which layer of the epidermis is found on thick skin only?
Stratum LUCIDUM
What are the layers of the epidermis?
- Stratum Corneum
- Stratum Lucidum (THICK SKIN BAS)
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
What is another name for stratum basale? And whys it called that
Germinativum (bc that’s where cells germinate)
Describe the stratum basale
What is kertain?
The fibrous protein that makesnup hair, skin, and nails
Describe the stratum spinosum
Describe the stratum granulosum
Describe the stratum lucidum
Describe the stratum corneum
Which layer of the epidermis has the most/least layer of cells?
Most: Stratum Corneum (25-30 layers)
Least: Stratum Basale (1 layer of stem cells)
Which layer consists of cornified cells?
Stratum corneum
Which layer consists of Dead, flat keratinocytes, that are shed and replaced by cells from deeper layers?
Stratum corneum
In which layer do the Cells contain nothing more than a bag of keratin (dead keratinocytes with lots of keratin protein)
Stratum lucidum
Which layer of the skin do the cells begin to produce keratin?
Stratum spinosum
In which layer of the skin do the cells become flattened?
Stratum Spinosum
Which layer of the skin Have Langerhans cells and melanin granules ?
Stratum spinosum
What do merkel cells detect?
Light, touch, and pressure
Which Specialized cells in the epidermis are 90% of all cells in the epidermis?
Keratinocytes
Which Specialized cells in the epidermis produce keratin that waterproofs and protects skin?
Keratinocytes
Which Specialized cells in epidermis produce darks pigment (melanin) that provides color of skin (and hair)?
Melanocytes
Which cells absorb radiation?
Melanocytes
Which Specialized cells in the epidermis protects the skin from U.V. light, and is found in the deepest layer?
Melanocytes
Which type of Specialized cells in epidermis are easily damaged by sunshine?
Langerhans cells
Which type of Specialized cells in epidermis are part of the immune system & interact with white blood cells and protect from infection?
Langerhans cells
How do merkel cells function in touch?
By contacting the flattened process of a sensory nerve called a merkel disc
Which type of Specialized cells in epidermis detect light, touch, and pressure and are found in the stratum basale?
Merkel cells
What do langerhans cells look like?
What do merkel cells look like? And what are they associated with?
Describe the process of keratinization
Cells die and produce outer layer that resists abrasion and forms permeability layer
Which cells desquamate (Older cells slough off/brushed off your body)?
Keratinocytes
What cells transfer pigment to
keratinocytes?
Melanocytes
What is the color range of melanocytes?
Yellow to brown to black
Amount of melanin produced depends upon?
genetics and exposure to sunlight
What causes and increase in melanin production?
Uv radiation
Skin color varies depending on the:
What are the neg effects of UV radiation?
What are the layers of the dermis?
What does each layer of the dermis contain?
Papillary layer: blood vessels, lymph, free nerve endings, and meissners corpuscles
Reticular layer: contains network of collagen and elastic fibers to resist tension, has hair follicles, nerves, sebaceous glands, and sweat
glands
What increases the surface area of the dermis papillary region?
Surface area of this region increased by dermal papillae which indent the epidermis in conical ridges
Which dermis layer is bigger?
The dermis-reticular region: it’s the lower 4/5th of the dermis
Which layer attaches to the hypodermis?
Dermis-reticular region
What are are responsible for finger prints?
And what do fingerprints help with?
- Surface area of this region increased by dermal papillae which
indent the epidermis in conical ridges - Epidermal ridges are downward projections of epidermis between
the papillae and increase surface area of epidermis
= finger prints help with friction
Why is the Interface between the papillary layer and reticular layer
indistinguishable ?
because the two layers are continuous with each other
What kind of tissue is present in the dermis- papillary region?
Areolar connective
What kind of tissue is found in the Dermis-reticular region?
dense irregular connective tissue with collagen and course elastic fibers
What do the collagen bundles and elastic fibers in the dermis reticular region provide?
strength, extensibility, and elasticity of skin
What does extreme stretching of the skin cause?
striae (stretch marks)
What sensory receptors are found in the reticular layer of the dermis? And what do they respond to?
Arrector pili muscles are usually found in the skin, but where can you also find them?
Skin of the penis and scrotum and the areola around the nipples
What is the Reticular Layer of the Dermis composed of?
dense, irregular collagenous connective tissue, displaying thick type I collagen fibers specially abundant near sebaceous and sweat glands
What are langer’s lines and what direction should u make an incision?
Describe the different types of scar tissue formation
