Integumentary System Structure Flashcards
integument
- skin
- cutaneous membrane
epidermis
superficial, thin, avascular layer of closely packed epithelial cells filled with keratin
epidermis epithelium
keratinised, stratified, squamous
epidermal cells
- keratinocytes
- melanocytes
- langerhans cells
- merkel cells
keratinocytes
- 90% of epidermal cells
- arranged in 4-5 layers
- produce keratin and lamellar granules
keratin
tough, fibrous protein that helps protect the skin and underlying tissues from abrasions, heat, microbes, and chemicals
lamellar granules
water-proofing and preventing microbe entry
melanocytes
- 8% of epidermal cells
- produce melanin and
carotene - transfer melanin to keratinocytes
- protection of nuclear DNA
from UV light damage
langerhans cells
detect pathogens and activate an immune response
merkel cells
detect sensations of touch
epidermal layers
- stratum corneum
- stratum lucidum
- stratum granulosum
- stratum spinosum
- stratum basale
dermis
dense, irregular CT with collagen fibres extending from one layer to the other
dermal cells
- fibroblasts
- macrophages
- adipose cells
fibroblasts
connective tissue building cells
macrophages
phagocytes
adipose cells
storage of lipids and lipid-soluble vitamins
dermis collagen and elastin fibres
give strength, elasticity and extensibility to skin
dermal components
- papillary layer
- reticular layer
papillary layer
dermal papillae extend into epidermis
reticular layer
dense collagen fibre bundles
hypodermis
subcutaneous layer of adipose tissue and loose CT containing collagen fibres
