Physiology Flashcards
What are Blaschko’s lines?
Developmental growth lines that follow the way that skin is drawn out
Which embryological layers do the epidermis and dermis originate from?
Dermis = mesoderm Epidermis = ectoderm
What are the 2 main layers of skin?
Epidermis Dermis
How many layers does the epidermis have and what are they from deep to superficial?
4 layers: Basal layer Prickle cell layer Granular layer Keratin layer
Describe the keratin layer of the epidermis?
layers of corneocytes and cornified envelope, the waterproof barrier for the skin
Describe the granular layer of the epidermis?
contains cells that burst and produce fillagrin (protein that binds to water so keeps water in skin and sticks everything together, people with eczema have less of this )
Describe the prickle cell layer of the epidermis?
daughter cells of basal cell layer contains desmosomes which makes it look prickley
Describe the basal cell layer of the epidermis?
Basal cell layer
Give the 4 types of cells found in the epidermis and what do they do/where are they found?
Keratinocytes - produce keratin, throughout epidermis Melanocytes - pigment producing dendritic cells, found in basal layer Merkel cells - mechanoreceptors (detect if something crawls over you), found in basal layer Langerhans cells - antigen presenting cells, found in prickle cell layer
Which type of cells contain Birbeck granules (look like tennis rackets)?
Langerhans cells
What are skin appendages?
anything that is on the skin e.g. hair, nails, sweat glands etc
What is the pilosebaceous unit?
hair follicle + sebaceous gland
What do sebaceous glands secrete?
Seramite
What are the 3 different stages of hair growth?
Anagen = growing phase Catagen = resting phase Telogen = falling out phase
What are the different parts of a hair follicle and draw it out?
Internal root sheath
Cortex
Medulla
Matrix
Papilla