Skin and tissues Flashcards
What are the 2 layers found in the skin?
Dermis and epidermis
What is the function of the epidermis?
Forms boundary between internal and external environments
What type of tissue is the epidermis?
Epithelial tissue
What is the function of the dermis
Supports and protects the skin and deeper layers, assists in thermoregulation and aids in sensation
What type of tissue is the dermis?
Connective tissue
Under the dermis lies what?
Hypodermis(adipose tissue under the skin, not part of the skin, it anchors skin to underlying structures)
What are the 4 types of epidermal cells?
keratinocytes
Melanocytes
Langerhangs cells
Merkel cells
What is the function of keratinocytes?
Extrude lipids making them water proof. They constantly self divide and regenerate, protecting them from trauma. (most common epidermal cell)
What is the function of melanocytes?
Responsible for pigment formation
What is the function of langerhans cells?
Responsible for immune surveillance
What is the function of merkel cells?
Touch receptors
Identify the cell type represented by A
Keratinocytes
Identify the skin cell type represented by B
Melanocyte
Identify the cell type represented by C
Langerhans cells
What are the layers of the epidermus?
Stratum basale
Stratum spinosum
stratum granulousum
stratum lucidum
stratum corneum
Does the epidermis have any blood vessels?
Nope
What is the function of the stratum basale
The cells in the stratum basale bond to the dermis via intertwining collagen fibres reffered to as the basement membrane. All of the karatinocytes are produced from this single layer of cells. As new cells are formed, the exisitng cells are pushed superficially away from the statum basale
What is a basale cell?
A cuboidal shaped stem cell that is a precursor of all the keratinocytes of the epidermis
What type layer is represented by A
Stratum corneum
What layer of the skin is represented by B
Stratum lucidum
What layer of the skin is represented by C
Stratum granulousum
What layer of the epidermis is represented by D?
Stratum spinosum
What layer of the epidermis is represented by E?
Stratum basale
Where does keratinisation begin?
Stratum spinosum
What occurs within the statum corneum?
This is where the converstion of keratohyalin to keratin takes place
How long does keratinisation take?
15-30 days
What is keratin?
An intracellular fibrous protein that gives hair, nails and skin their hardness and water-resistant properties
What structures are located within the dermis?
Blood and lymph vessels. nerves and other folliceles such as sweat glands
What aer the 2 layers located within the dermis?
Papillary layer and reticular layer
What is the papillary layer?
A superficial layer of dermis that projects into the strtum basale of the epudermis to form finger like dermal papilla (plural=dermal papillae)
What is the function of dermal papillae
They increase the strength of the connection between the epidermis and the dermis - the greater the folding, the stronger the connections made
What type of tissue is the papillary layer?
Loose connective tissue
What type of tissue is the reticular layer?
Irregular connective tissue
What is the function of the reticular layer?
The treticular layer appears reticulated (net-like) due to a tight meshwork of fibres. Elastin fibres provide some elasticity to the skin, enabling movement.
Collagen fibres provide strcture and tensile strength, with strands of collagen extending into both the papillary layer and the hypodermis