Skin Flashcards
What is the intergumentary system made up of?
skin, hair, nails, glands and sensory receptors
What are the two types of skin on the body?
Hairy and Glabrous
What are the 4 functions of skin?
- Protection
- Thermoregulation
- Humidity control
- Produces vitamin D
What is the epidermis?
Outer layer of skin with no blood vessel supply
Also contains melanocytes, Merkel cells and Langerhans cells
30-45 days for basal cells to mature and migrate to top of epidermis
What are the 5 layers of the epidermis?
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
What are the two parts of the dermis?
- Papillary (20%) mostly loose connective tissue
- Reticular (80%) dense irregular connective tissue
What are the 6 cells in the epidermis?
- Fibroblasts and keratinocytes
- Macrophages: immunity
- Adipocytes: fat cells
- Mast cells: wound healing
- Myofibroblasts:
- Myoepithelial cells: sweat glands
What are keratinocytes?
Make up more than 90% of the cells in the epidermis
Essential for forming protective barrier
What are Desmosomes?
- Connect cells to each other
- provide strength
What are Lamellar granules?
- Produced by keratinocytes
- Round/ oblong in shape
- Secretory organelles required for desquamation
- help form the impermeable lipid-containing barrier
What is keratin?
- a major component of the cytoskeleton
- Network of fibre bundles
- Bundles composed of keratin make coils
- Contribute to the structural integrity
What are hemi-desmosomes?
- connect keratinocytes to the basement membrane
receptors and contribute to strength - Loss can again lead to skin blistering
What are the melanocytes?
Produce melanin and protects against UV radiation while supporting the immune system.
Found in bottom layer of epidermis.
What are langerhans cells?
also known as dendritic cells and contain Birbeck granules
Found throughout epidermis and support immune system.
What are merkel cells?
oval-shaped and responsible for light touch and sensation through their connection to nerve fibres.
What is hyperpigmentation?
- Discoloured or darkened skin caused by increased melanin production
- treatment with photoprotection to prevent new spots or melanin inhibitors
What is allodynia?
- Hypersensitivity to touch which can manifest as a type of neuropathic pain
- Everyday tasks become difficult
- Caused by diabetes, fibromyalgia, migraines etc
What is langerhan cell histiocytosis?
- Buildup of excess immature Langerhans cells form tumours in the skin, unknown cause
- Cancer?
- Rare (1 in 5 million)
- Can severely affect the immune system and even be fatal)
What is the anatomy of the nail?
- Nail body formed on the nail bed
- Lunula: Crescent shape at the base of the nail
- Keratin-rich and densely packed dead keratinocytes
- For protection
What are the 4 types of glands in the skin?
sudoriferous glands
sebaceous glands
ceruminous glands
mammary glands
What are the three ways of secretion?
- Merocrine- most common. Excretion via exocytosis
- Apocrine- cell membrane buds off into the duct
- Holocrine- cell membrane ruptures to release the product
What are sudiferous glands?
Sweat glands
- Eccrine (surface of skin)
- Apocrine (hair follicles)
What are sebaceous glands?
Oil-producing glands that release sebum into follicular duct
What are ceruminous glands?
apocrine glands found in the external auditory canal
produce ear wax
protective role
1000-2000 ceruminous glands in a normal ear
What are mammary glands?
Type of apocrine gland
Production of milk after birth
Each weighs 500-1000g
What are mechanoreceptors?
Respond to physical changes
Meissner’s corpuscle: indentation and slipping
Pacinian corpuscle: vibrations
Merkel’s disk: texture
Ruffini corpuscle: stretch
What are thermoreceptors?
Body has both cold receptors and warm receptors
When changes in temperature occur, the opposite receptor stops discharging
What are nociceptors?
- Signal pain related to pressure, temperature and chemicals
- triggered by tissue damage
What is atopic dermatitis?
Chronic, recurrent and inflammatory disease of the skin
Affects both children and adults
How does the skin repair wounds?
- Haemostasis: platelet aggregation to stop bleeding
- Inflammation: Influx of cells begin inflammatory process
- Proliferation
- Maturation
What are three means of transdermal drug delivery?
Intercellular: In between cells
Intracellular: Through cells
Follicular: Through hair follicles
What is the bricks and mortar model of the skin?
- Bricks: Corneocytes
- Mortar: Lipid matrix
What are the 6 active delivery methods?
- Iontophoresis: moving ions
- Sonophoresis: ultrasound
- Electroporation: creating pores using electric impulses
- Photomechanical waves: using photodynamic waves to penetrate
- Microneedle
- Thermal ablation: localised heat to create microchannels
What is an ITS?
Iontophoretic transdermal system
What are the 3 passive delivery systems?
Vesicles: water-filled particles with a bilayer to carry drugs
Polymer nanoparticles
Nanoemulsion: a mixture of oil and water
What is regenerative medicine?
Isolation of cells in lab
Once desired cell number is reached, biocompatible material is combined
Cell and scaffold material stimulated in lab until mimics the tissue
Reintroduced to patient
