Skin Flashcards
What are the 4 primary tissue types?
- Epithelium
- Connective tissue]
- Muscle
- Nerve
What are epidermal cells termed as?
Keratinocytes
What is the function of the epidermis?
Prevents water loss by evaporation
What are the functions of the dermis?
- Reduces the risk of external injury
- Maintains the epidermis by its blood flow
- Permits body cooling
- Immune surveillance
- UV protection
- Energy storage
- Sensory information
What does the epidermis consist of?
Epithelium which forms boundaries between internal and external compartments
What does the dermis consist of?
Connective tissue which give structural support
How can epithelial be described?
Stratified squamous keratinising epithelium
What kind of origin does epidermis have?
Ectodermal origin
What are the 4 types of epidermal cells?
- Keratinocytes
- Melanocytes
- Langerhans cells
- Merkel cells
Describe keratinocytes.
- Most frequent
- Contain keratin
- Hard and resistant to abrasion
- Extrude lipids making it waterproof
- Constantly dividing
What is the function of melanocytes?
Pigment formation and injection of melanin in the str. germinaticum
What is the function of Langerhan cells?
Immune surveillance
What is the function of Merkel cells?
Touch receptors
What are the 5 layers of the epidermis from outside in?
- Stratum corneum
- Stratum lucidum
- Stratum granulosum
- Stratum spinosum
- Stratum basale
Describe the stratum spinosum.
- Spinous layer
- Cells shrink post mortem and desmosomes create spines
- Little structural evidence of activity
- Preparative layer for keratinisation