Dermal Structures and Diseases Flashcards
Blood vessels, nerves, and cutaneous appendages are found in what layer of the skin?
Dermis
What is the thickness of the dermis?
1-4mm
True or False: The epidermis contains blood vessels.
False
What composes the dermal matrix?
Collagen fibers, elastic fibers and ground substances.
What synthesizes the dermal matrix?
Dermal Fibroblasts
What are epidermal retes?
Downward projections of epidermis
What are dermal papillae?
Upward projections of dermis
What are the functions of epidermal retes and dermal papillae?
They increase the strength of adherence of the epidermis to the dermis and increase surface area.
What does the interlocking epidermal rete and dermal papillae create?
Fingerprints
What is the function of collagen in the dermis?
It provides tensile strength to the skin
Which form of collagen comprises more than 85% of the weight of the dermis?
Collagen I
What form of collagen comprises a large part of the fetal dermis?
Collagen III
What form of collagen is found in high concentration in the “basement membrane zone” and is also prominent around the vessels?
Collagen IV
What type of collagen functions to attach the epidermis to the dermis?
Collagen VII
Procollagen is synthesized intracellularly within what type of cell?
Fibroblast.
Procollagen is comprised of three separate chains of proteins arranged in an alpha- helical. What three proteins form this structure?
Gly-X-Y
glycine)-(proline)-(hydroxyproline
Where are the collagen fibrils assembled? Intracellularly or extracellularly?
Extracellularly
A 72yo retired engineer alcohol male who lives alone is admitted to the hospital for evaluation of wounds on limbs that are not healing well. Multiple ecchymoses are located on his posterior thigh and anterior arm. His skin reveals miinute hemorrhages around hair follicles and splinter hemorrhages around nail beds. His hemoglobin is 9 (normal is 14-18g/dL). What is this patient most likely suffering from?
Scurvy
Scurvy is an acquired abnormality in collagen production as a result of what kind of deficiency?
Vitamin C
Ehlers-Danlos syndrome (EDS) is a congenital abnormality that caused by a disruption in what process?
Collagen synthesis.
What are four clinical characteristics shared by all subtypes of Ehlers-Danlos syndrome (EDS)?
- Skin hyperextensibility (COLLAGEN DEFECT)
- Joint hypermobility
- Tissue fragility
- Poor wound healing
What is the function of elastic fibers?
Resiliency