Week 1 Flashcards
(93 cards)
What is the difference between prevelance and incidence?
Prevelance= number of people in the population at any one time that have a particular disease incidence= number of new cases of a disease over a fixed period of time
What lines mark the developmental growth pattern of skin? If a condition follows these lines what is it a sign of?
Blaschko’s lines
sign of congenital/embryological skin condition
What form of epithelium is the epidermis composed of? What are the majority of the cells called?
stratified squamous epithelium
keratinocytes
Identify the four layers of the epidermis and list them in order
Keratin layer
granular layer
prickle cell layer
basal layer
How thick is the basal epidermal layer? What shape are the cells? How do the cells of the prickle cell layer differ?
One cell thick usually
small cuboidal
larger polyhedral cells with many desmosomes
What structural proteins are packed into granular layer cells?
Filaggrin and Involucrin
What are the cells of the keratin layer of the epidermis called? What makes it suitable to be the most superficial layer? What major organelle is absent?
Corneocytes
Tight waterproof layer
nuclei
Apart from keratinocytes name three other cells found in the epidermis
melanocytes
Langerhans cells
Merkel cells
From where do melanocytes originate? What pigment do they produce? What organelles do they possess? what is the function of this pigment?
neural crest
melanin
melanosomes
absorbs light
What is the function of melanin caps?
they cover the nuclei of basal cells to protect their DNA
What is Vitiligo?
An autoimmune disease causing loss of melanocytes
What is Nelson’s syndrome?
A disorder where melanin stimulating hormone is produced in excess by the pituitary gland
What are Langerhans cells?
Dendritic cells which are found in the prickle cell layer and Dermis. they detect antigenic material
What are Merkel cells? What causes merkel cell malignancy?
Mechanoreceptors of the skin
infection
Give another name for a hair follicle
pilosebaceous unit
What muscle is associated with the pilosebaceous unit?
Arrector pili muscle
Name the three phases of hair growth
Anagen
telogen
catagen
What contributes to the pigmentation of hair?
Melanin from melanocytes
What supplies blood to the hair follicle?
Hair Papillae
What is the name of hair loss that can occur during periods of systemic stress
Telogen effluvium
What is the name of autoimmune hair loss?
Alopecia areata
What do you name the half moon shape of the nails? From what area does the nail grow?
lunula
nail matrix
What gland is associated with the hair follicle? What does it produce and what is its function?
sebaceous glands
sebum- acts as an emollient (Moisturiser)
What is the name of the interface between the dermis and epidermis?
Dermo-epidermal junction