Skin Flashcards
What are the divisions of the Epidermis in thick skin?
Name them in order, from the surface downward.
Stratum Corneum Stratum Lucidum Stratum Granulosum Stratum Spinosum Stratum Basale
What are the divisions of the epidermis in thin skin?
Name them in order, from the surface downward
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
What are the two types of skin?
Thick, non-hairy skin
Thin, hairy skin
What are the 3 exceptions to: Thick, non-hairy skin, Thin, hairy skin?
Eyelid
External Genitalia
Back of the ear
Name and describe the 3 types of hair
Lanugo: - Covers the fetus Vellus: - Replaces the Lanugo - Thin and Soft - Not connected to a sebaceous gland Terminal: - Rough and coarse - Thick - Axillia, head - Testosterone mediated
Name the different receptors found in skin and their function? (6)
Nociceptors: Pain
Tactile disk of Meissner: Touch and texture
Tactile disk of Merkel: Touch, texture and pressure
Ruffini’s corpuscle: Joint movement and tissue stretch
Pacinian Corpuscle: Vibration
Root hair plexus: Vibration of the hair shaft
What is a Arrector Pili, where is it found and what is its function?
What: Smooth muscle fibres Function: Controlling pilorelaxation/erection Sebum release during stress from associated sebaceous gland - lubrication Location: Origin - Papillary Dermis Insertion - Hair bulb
Name the 3 specialised cells found in the epidermis, and state their function and structure
Melanocytes: - Synthesis of melanin - Long dendritic projections - Melanosomes synthesise melanin Langerhans cells: - Antigen Presenting cells - Hard to see without immunofluroescence Merkel cells: - Sensory cells on mechanoreceptors (touch, pressure and texture) - Hard to see
Name the functions of the skin (8):
Protection and repair:
- Langerhans and mast cells, macrophages: disease
- Keratinocytes : abrasion from surface
- Melanocytes: UV damage
- Myofibroblast: Wound repair (papillary Dermis)
Thermoregulation:
- Hairs and sweat glands
Lubrication:
- Sebaceous glands secrete sebum
Storage:
- White adipose tissue
Vitamin D Synthesis
Absorption
Aesthetic
Sensation
Describe the steps of development for a keratinocyte
Tonofibrils synthesised in the Stratum Basale
Lamellar bodies synthesised in the stratum Spinosum
Lamellar bodies combine Tonofibrils and keratohyaline in the stratum Granulosum to form keratin and apoptosis begins
(Stratum Lucidum contains intermediate Eladin)
What is the normal Transit time for a keratinocyte, name a disease which may affect this and describe its symptoms:
Normal: 28-40 days
Psoriasis: 2-3 days
- Silvery Scales (abundance of keratinocytes)
- Dry, red pathes of skin
Describe the nature and symptoms of Hyperkeratosis:
The increased production of keratin in keratinocytes
Thicker tougher skin
Often a result of pressure or irritation.
Symptoms:
- Calluses
- (Abnormally) Rough hard skin
Describe the characteristics and Function of Thick non-hairy skin
Characteristics: - No Arrector pili, Hair follicles or sebaceous glands - Thinner Dermis - More Mechanoreceptors - Thicker Stratum Corneum - Stratum Lucidum Present - Regular Dermal Papillae - Pronounced ridges (fingerprints) Function: - Protection from abrasion - Increased grip - Increased Sensation
Describe the characteristics and Function of Thin hairy skin:
Characteristics: - No stratum lucidum - Irregular Dermal Papillae - Less pronounced ridges - Sebaceous gland, arrector pili and hair follicles present Function: - Thermoregulation
Name the 2 types of Malignant melanoma, state which is more common
More common: Nodular
Less Common: Lentigo
