Integumentary System
Hair root – a knot of sensory nerve endings which wraps around each hair bulb Hair shaft – part of the hair that projects outside the skin; made mostly of keratin (tough protein produced by kerat Hair bulb matrix – actively dividing germinal layer
Epidermal sheath – composed of epithelial cells; inner layer of follicle Dermal sheath – composed of connective tissue; outer layer of follicle Connective tissue papilla – protrudes from dermal sheath; provides nutrition
Melanocytes – cells that produce melanin (pigment responsible for skin & hair color) Arrector pili – smooth muscle which connects the hair follicle to the dermis Responsible for “goose bumps”
kin-care-101/arrector-pili- muscles
Cuticle – outer most layer Cortex – middle layer Medulla – innermost layer
Damaged cuticle Normal cuticle remy-hair
Free edge - visible unattached portion Body – visible attached portion Root – embedded in the skin; adhered to nail bed Nail fold – skin that overlaps the nail (lateral and proximal) Nail bed – composed of epithelial tissue
Nail matrix – thickened proximal part of the nail bed responsible for nail growth Lunula – visible part of nail matrix Cuticle or eponychium – next to proximal nail fold