Skin Flashcards
Functions of the Skin
Protection from Pathogens (Langerhans in skin ) Controlling Evaporation Vitamin D synthesis Storage Thermoregulation Sensation Excretion
The 3 Layers in skin
Epidermis - Stratified Squamous Keratinising Epithelium
Dermis - Dense irregular connective tissue
Hypodermis - adipose tissue
Strata of skin
Outermost:
Statum Corneum - Cells almost entirely made of Keratin
Lucidum - Thick Skin
Granulosum - 2 -3 Layers of skin, contains lipid rich water sealant.
Spinosum - 2-8 layers of cell, desmosomes and tonofilaments
Basale - innermost, single layer of cuboidal cells bonded by hemidesmosomes to basal lamina and dermis, site of keratinocyte cell division.
Role of Keratinocytes
Produce Keratin
Melanocytes
Produces Melanin, protects against U.V, determine skin colour.
Langerhan cells
Present antigens
Merkel Cells
Sensitive Mechanoreceptors, essential for light touch sensation
Cells present in the Epidermis
Merkel Cells
Langerhan Cells
Melanocytes
Keratinocytes
Composition of Dermis
Primarily composed of collagen, little elastin and reticular fibres.
Fibroblasts
nerve fibres, sensory receptors, blood/lympatic vessels
Papillary (superficial ) Reticular (Deep ) layers.
Role of Hypodermis
Provides padding and anchors skin to underlying tissue.
Subcutaneous fat provides energy and insulation
Absorbs drugs quickly
Role and Positioning of Merocrine sweat glands.
High density in palms/soles
Produce sweat which evaporate to cool body
Role and Positioning of Apocrine sweat glands.
axillary and anogenital regions
secrete protein rich sweat into hair follicles
Hair Follicles
Extend from epidermis to dermis
Associate with sebaceous glands and have arrector pilli muscle
what is Hair
Elongated Keratinzed structures which grow discontinuously
Sebaceous glands role
Secrete Sebum into the base of the hair follicle for lubricaton, waterproofing and to kill bacteria
