Tissues 10 (Skin) Flashcards
What is the structure of skin?
- Startup cornea
- Epidermis
- Papillary dermis
- Reticular dermis
- Hypodermis
What is the structure of the epidermis?
- keratinocytes start at basement membrane and differentiate as they move up to stratum corneum
- Separated into 4 layers
What are 3 cell types found in the epidermis and their functions?
- Langerhan cells: antigen presenting
- Merkel: sensation
- Melanocytes: produce melanin
What is the result of a mutation in filagrin gene?
Glue between corneocytes in epidermis is not normal (eczema)
What are the 4 layers of the epidermis ?
- Stratum basale: basal cells (connect to basement membrane)
- Stratum spinous: prickle cells (keratin-producing) & desmosomes
- Stratum granulosum: cells have keratin granules
- Stratum corneum: cells have no nuclei (corneocytes - protective)
Where are melanocytes found and their function?
- Basement membrane of epidermis
- produces melanin (protects against UV)
What is the Vitamin D deficiency in children called?
Rickets = soft and fragile bones
How are the dermis and epidermis held together?
Complex proteins hold the epidermis and dermis together at the basement membrane
What is epidermolysis bullosa?
- defect in protein holding dermis & epidermis together
- Layers aren’t connected properly
- Get blisters
What does the dermis contain?
- Collagen
- Elastin
- Glycosaminoglycans GAGs
- Fibroblasts
- Immune cells
- blood/lymph vessels
What are the 2 types of sweat glands?
- Eccrine: all over body, salty sweat
- Apocrine: under hair follicle, viscous sweat can be metabolised by bacteria
What is Embryology of epidermis, dermis and melanocytes?
- Epidermis: ectoderm
- Dermis: mesoderm
- Melanocytes: neural crest
What are the functions of skin?
- Protection against injury, pathogens & radiation
- Vitamin D production
- Waterproofing & fluid conservation
- Sensory organ
- Cosmetic
- Thermoregulation
What separates the epidermis from the dermis?
basement membrane
What are the 2 hair pigments?
- eumelanin: dark pigment in black/brown hair
- pheomelanin: lighter pigment in red hair
