Structure Flashcards
What are the layers of the skin ( top and bottom)
Epidermis
Dermis
Hypodermis
Layers of the epidermis ( top to bottom)
Keratin Granular Prickle Basal ( Kirsty grabs pickle burger)
What is the epidermis made out of
Stratified squamous epithelium
What cells does epidermis contain
Keratinocytes, melanocytes, langerhans and merkel cells
Epidermis thickness changes throughout the body, where has the thickest skin
Hands and feet
What regulates epidermal cells
Growth factor, cell death, hormones
Features of keratin layer
Corneocytes ( flat cells without the nuclei)
Has keratin and fliagggin
It keeps water in as its a tight waterproof barrier
Features of granular layer
Flatter than the granular layer
Contains keratohyalin granules and structural flaggrin - required to keep water in
2- 3 cells thick
Features of prickle layer
Polyhedral cells
Has desmosomal, intermediate filaments connect to desmosomes
Features of basal layer
One cell thick
Small cuboidal shape cells
Has intermediate filaments
Very metabolically active
Function of melanocytes
Known as the pigment cell
Makes melanin - transports it along to a synapse to a keratinocytes and they spread the melanin granules
They convert tyrosine to 2 different types of melanin pigment
What are the 2 different types of melanin and their colours
- Eumelanin ( brown /black)
2. Phaeomelanion ( red, yellow)
What is the difference in the following terms :
- vitiligo
- albinism
- nelson syndrome
- melanoma
- autoimmune, something destroying the melanocytes
- no melanin
- melanin stimulating hormones is produced in excess by pituitary
- malignant cell line of melanocytes
Where are merkel cells located
Basal layer between keratinocytes and nerve fibres
Function of merkel cell
Mechanoreceptors - allows sensation. Connects to free nerve endings - direct entry point to CNS
Where do langerhans cells stay
Prickle cell in epidermis
Function of langerhans cells
Samples things that come into the skin - find invasions and takes them to regional lymph node to present to professional cells
What are blaschko’s lines
Growth pattern of skin ie one cell affected - whole line will be
Main tissue groups in skins
Nervous Epithelium Glands Muscle Hair Adipose tissue Connective tissue Nails
What separates the epidermis and the dermis
Dermo - epidermal junction
Function of the dermo - epidermal junction
Anchorage, skin adhesion, filter to let things pass the dermis
What happens if the DEJ fails?
Bullous pemphigoid : antibody produced to fight the junction
Epidermolysis bullous : defects in the protein making the junction
What unit is the hair follicle apart of?
Pilosebaceous unit
What Are the phases of growth
Anlagen : growth
Catagen : involuting
Telegen : resting ( falls out)
What’s the difference in these terms
Telegenon effluvium : all hair falls out due to stress
Virilisation / hirsutism :women get male pattern hair due to excess androgen from a tumour
Alopecia areata : autoimmune hair loss
What is in the pilosebaceous unit
Hair follicle
Hair shit
Arrector pilli msucle
Sebaceous glands
What cells are in the dermis
Fibroblasts, macrophages, mast cells, lymphocytes, langerhans cells
What does fibroblasts produce
Collagen and elastin
What else ( other than cells) is in the dermis
Muscles, blood vessels, lymphatic vessels
What is a food allergy
Adverse immune response to flood, can be IgE or not
What is a food intolerance
Non immune response
What is acanthosis nigiricians
A velvety thickening and pigmentation of the skin folds e.g. armpits, neck
What is hidradenitis suppurativa
A chronic inflammatory disease where boils and abscesses form and scar in apocrine gland areas
What is androgenetic alopecia
Male pattern balding in men / women
What stretch marks
Dermal CT injury in response to local stretching forces
What manifestations of skin caused by obesity
Acanthosis nigiricans Skin tags Hirsutism Acne Hidradenits suppurtiva Androgenetic alopecia Stretch marks
What diseases are caused by obesity
Lymphoedema chronic venous insufficiency Skin infections Intertigo Psoriasis
Another name for keratin layer
Stratum corneum
What happens to ketarinocytes
Usually differentiated to corneocytes
What is the main skin resident immune cell
Langerhans cells
What are langerhans cells characterised by
Birbecks granules
Where are T cells found in the skin
Epidermis and dermis
Where are CD8 + T cells found
Epidermis
Where are CD4+ and CD8 + T found in
the dermis
What T helper is assoc with psoriasis
TH1
What t helper is assoc with atopic dermititis
TH2
What T helper is assoc with psoriasis and atopic dermatitis
TH17
What is hyperkeratosis
Increased thickness of keratin layer
What is parakeratosis
Persistence of nuclei in the keratin layer
What is acanthosis
Increased thickness of epithelium
What is papillomatosis
Irregular epithelial thickening
What are the 4 inflammatory skin disease classification
Spongiotic - intra epidermal oedema
Psoriasiform - elongation of the reta ridges
Lichenoid - basal layer damage
Vesiculobullous - blistering
