Skin Flashcards
What is the skin?
Largest organ in the body- acts as a combination of the 4 primary tissues.
What is the name of the skin system?
Integumentary system.
What are the 3 layers of the skin?
Epidermis- outer (epithelial, covers surfaces)
Dermis- middle (connective; gives structure)
Hypodermis- inside layer
What is the epidermis?
Outer layer of skin.
What does the epidermis consist of?
5 strata.
What type of epithelia is the epidermis?
Stratified squamous keratinising epithelium.
What are the 4 types of epidermal cell?
Keratinocytes- keratin/sulfur for hard resilience
Melanocytes- pigment formation
Langerton cells- immune surveillance
Merkel cells- touch receptors
What do keratinocytes do?
Contain keratin and sulfur to provide resilience.
What are melanocytes responsible for?
Pigment formation.
What are Langerton cells responsible for?
Immune surveillance.
What are Merkel cells responsible for?
Touch receptors.
What do the epidermal layers act as?
A continuum from basement membrane to skin surface.
Are the epidermal layers sharply defined?
No.
What is keratinisation?
Organic process by which keratin is deposited in cells.
Why does epidermal thickness differ?
Some areas require thin or thicker skin (e.g. hands and feet).
What are the 2 layers of the dermis?
Papillary layer (loose connective tissue- cellular) Reticular layer (dense connective tissue- fibrous)
What does the papillary layer consist of?
Loose connective tissue- cellular nature.
Cellular, protective against pathogens, blood vessels and nerve endings present.
What does the reticular layer consist of?
Dense connective tissue- fibrous nature.
Collagen bundles, elasticity.
What is waterproofing a function of?
Epidermis.
What waterproofs the cells?
Keratinisation
Intercellular spaces also filled with lipid cement.
How does keratin originate?
Originates as lamellate granules in the stratus granulosom.
What is skin colour regulated by?
Melanin.
What is the function of hair?
Thermoregulatory but not in humans.
Where do hair follicles originate?
Epithelial layer.
What are nails protected by?
Nail plate- keratin surface.
Nail bed underneath.
How is the nail bed structured?
Specialised form of epithelium, has the same 4 layers of the epidermis as skin, nail plate analogous too s. corneum.
What are the types of gland in the skin?
Sebaceous- hair follicles/sebum
Apocrine- protein-rich BO
Eccrine- sweat
Where are eccrine (sweat) glands located?
Dermis, thermoregulatory water secretion.
How does skin repair?
Coagulation pathways.
