Basic Principles - Skin Flashcards
What are the functions of skin?
Protection
Anatomical barrier
Control of evaporation
Sensation
Thermoregulation
Production of vitamin D
Absorption
What epithelium does skin have?
Stratified sqaumous keratinising epithelium.
What are the 5 layers of the skin?
Stratum corneum - surface, keratin
Stratum lucidum - thick skin
Stratum granluosam - granules containing lipid rich secretion, water sealant
Stratum spinosum - desmosomes
Stratum basale - single layer of cuboidal cells
Give 4 cells of epidermis and their function.
Keratinocytes - produce keratin
Langerhans - antigen presenting cells
Melanocytes - synthesise melanin, located in basal layer
Merkel cells, sensitive mechanoreceptors
What is the dermis?
Dense irregular CT abundant in collagen.
Papillary layer - interdigitates with epidermal ridges.
Reticular layer - deeper region attached to hypodermis.
What is the hypodermis?
The hypodermis, also known as the subcutaneous tissue or superficial fascia, is the deepest layer of the skin.
It lies directly beneath the dermis and is composed primarily of adipose tissue and connective tissue
Functions;
Insulation - layer of adipose tissue reduces heat loss
Energy storage - adipose tissue serves as a reservoir of energy
Shock absoprtion - provides a cushioning effect protecting tissues + organs
Attachment - anchors the skin to underlying structures such as muscles and bones
Blood vessel passage - Blood vessels and nerves that supply the skin and underlying tissues pass through the hypodermis, providing nourishment and sensation to the skin
What is the difference between thick and thin skin?
Thick skin has a thinner dermis than thin skin, and does not contain hairs, sebaceous glands, or apocrine sweat glands
What are the 2 types of sweat glands?
Merocrine - highest density in palms and soles
Apocrine - axillary and anogenital regions
What are hair follicles?
Hairs are elongated keratinised structures that form within epidermal invaginations
Hair grows discontinuously
Arrector pilli muscles are attached to hair follicles and contraction of them causes hairs to stand on end.
