Structure and Function of Skin IV Flashcards
What are some functions of the skin?
Barrier function, metabolism and detoxification, thermoregulation, immune defence, communication, sensory functions
What occurs in toxic epidermal necrolysis?
Splitting of the dermis
What is erythroderma?
Red skin
What physical things is the skin a barrier against?
Friction, mechanical trauma, UV radiation
How does melanin help protect the skin?
Absorbs UV rays to protect DNA in the cell nuclei
What chemicals does the skin protect against?
Irritation, allergens, toxins
What is Steroid sulphatase deficiency and why does it occur?
Form of X-linked ichthyosis caused by epidermal barrier failure
What are two examples of substances that undergo metabolism in the skin?
Vitamin D and Thyroxine
Why is UV light needed for vitamin D metabolism?
Rays of 290-320nm are needed to convert cholecalciferol to vitamin D3
What is thyroxine converted to, and where does this mostly occur?
It is converted to Tri-iodothyronine; 80% occurs in structures peripheral to the thyroid (e.g the skin)
How does thermoregulation offer protection?
Protects against being too hot/cold
What do the warm/cold thermoreceptors of the skin do?
Cause behavioural changes, control sweating/shivering/blood supply
What are some things that the immune defences of the skin are involved in?
Infection, sunlight responses, allergic reactions
What causes crusted scabies?
Mites burrow under the skin under the keratin layer; there is an abnormality in the immune response which causes an exaggeration of the response
What occurs in Tuberculoid leprosy?
Huge response to few bacteria causes nerve damage
