Integumentary System Flashcards
What functions does the skin provide?
Barrier
Immunologic
Homeostasis
Sensory information
Endocrine
Excretion
Outline the skin layers
Epidermis (several layers, stratified squamous keratinized epithelium)
Dermis (blood/lymph vessels, nerves, appendages)
Hypodermis (not considered part of skin, a loose connective tissue)
What is the mnemonic for remembering epidermis layers?
Come Lets Get Sun Burnt
List the 5 epidermis layers
Stratum corneum (dead, keratinized)
Stratum lucidum (only in thick skin)
Stratum granulosum
Stratum spinosum
Stratum Basale (stem cells)
What cells are found in the epidermis?
Keratinocytes
Melanocytes
Langerhans
Merkel
What do keratinocytes do?
Produce keratins
Help form the epidermal water barrier
What condition has a high epidermal turnover?
Psoriasis (8-10 days, normal is around 47)
What do merkel cells do?
-Detect touch sensations
- Most abundant at acute sensory perception
- Lobed nucleus
- Cytoplasm contains neurosecretory granules
What do melanocytes do?
- Produce melanin granules
What is the purpose of melanine?
To protect cell DNA against UV radiation
What conditions are melanocytes associated with?
Albinism (cannot synthesize melanin)
Virtiligo (degeneration/disappearance of whole cell)
Melanoma
What do Langerhans cells do?
- Immunological function
- Encounter, process and express antigens
- Antigen presenting cells
- Move to lymph nodes
What are three epithelial appendages?
Hair follicle/hair
Nails
Gkands (sebaceous, eccrine, apocrine)
All extend into dermis
What are the three layers of hair?
Medulla (central)
Cortex (differentiating cells)
Cuticle (squamous cells, outer layer)
Outline the three glands in skin
Eccrine - sweat, over entire body, especially thick skin, evaporation of sweat cools body
Apocrine - sweat, localised to groin area
Sebaceous - discharge secretion into follicle, secretion is rich in lipid
