Skin Flashcards
Epidermis structure x3
- Epithelial
- Avascular
- Synthesises keratin
Dermis structure x3
- Strong CT
- Collagen & elastic fibres
- Quite vascular
Hypodermis structure x3
- Looser CT
- Superficial fascia
- Blood vessels, lymph
Where are glands in the skin?
Buried in dermis/hypodermis
Epidermis layers x5 (base –> surface)
- S. Basale
- S. Spinosum
- S. Granulosum
- S. Lucidum
- S. Corneum
S. Corneum
- layer (from base)
- structure
- 5th
- Water-proof cell ghosts
S. Lucidum
- layer (from base)
- processes
- 4th
- Specialised death programme
S. Granulosum
- layer (from base)
- processes
- 3rd
- cells accumulate keratohyaline granules & start to die
S. Spinosum
- layer (from base)
- structure
- 2nd
- Spiky= diff. immediate filaments join through desmosomes
S. Basale
- layer (from base)
- processes
- 1st
- Stem cells divide
Stratum Basale
- what cells
- function
- Stem cells
- Anchoring layer –> hemidesmosomes link w CT underneath
How does S. Basal connect to the BM
Hemodesmosomes
How does the dermis anchor to the basal lamina (= S. Basal BM)
Collagen VII
What happens if collagen in the S. Basal is mutated
Blistering
Stratum Spinosum
- structure
- expression of…
- at ‘end’ near S. Granulosum…
- Spikey –> due to desmosomes
- K1 & K10 (keratin)
- Filaggrin –> organises filaments as the cells die
Filaggrin
- what
- where
- when
- function x2
- Main component of keratohyaline granules
- Stratum Spinosum
- As cells start their death programme
- Organises filaments as the cells die
- Natural moisturiser
Melanocytes
- where
- what
- function
- Basal layer
- Release melanin
- Absorbs UV, preventing DNA damage
Keratinocytes & melanin
Engulf melanin molecules –> form melanosomes
Langherhans cells (monocytes)
- where
- structure x2
- function
- Epidermis
- Dendritic (big processes)
- Specialised lysosomes –> can degrade viruses
- Migrate to lymph nodes & present antigens
Dermis
- sections x3
- Demo-epidermal junction
- Papillary dermis
- Reticular dermis
What is the dermo-epidermal junction
- Where collagen VII connects in the dermis (to the epidermis)
What is the papillary dermis?
- Contains lymphatics, sensory nerve endings
- Less dense than reticular dermis = below
What is the reticular dermis?
- Below the papillary dermis
- Coarse collagen & elastic fibres
Hypodermis
- structure
- components x4
- Loose connective & adipose tissue
- Sweat glands
- Hair follicles
- Vascular
- Ligaments –> determine skin motility
Sweat glands in skin x2
- Merocrine/eccrine
- Apocrine
Merocrine/eccrine glands
- structure
- Function
- Tubular gland = straightens into tubular duct
- Thermoregulation –> sweat
Apocrine glands
- structure
- secretion
- In axillae, around hair follicles
- Alkaline –> odorous –> pheromones
Hairs
- structure
- location
- gland
- movement
- Modified epithelium (as rod of keratin)
- Hair follicle in hypodermis
- Sebaceous –> = oil secretion gland
- Arrector pilli miscela –> driven by autonomic nervous system
Pilosebaceous unit
- components x4
- Hair follicle
- Sebaceous glands
- Hair shaft
- Arrector pili muscle
What are mammary glands?
Modified apocrine glands
Functions of skin x3
- Barrier
- Strength
- Secretion
Multifunctional skin
- what it does x3
- Protection (UV, organisms)
- Homeostasis (metabolic, temp. reg)
- Sensory info
Mutations resulting in less filaggrin cause….
Larger risk of eczema (50% of eczema cases = this mutation)
