BIOL 141 Lecture Notes - Lecture 5: Stratified Squamous Epithelium, Stratum Corneum, Lamellar Corpuscle
Document Summary
Dermis: inner, connective, smooth muscle, nerves and blood vessels. Keratinization: hardening of cells by expression of waterproof keratin proteins. Protection from water loss, mechanical injury, harmful chemicals, and microorganisms. Melanocytes: specialized cells in the stratum basale that produce melanin. Melanin: dark pigment that provides skin color and absorbs uv light. Dermal papillae: cones of dermis extending into epidermis (fingerprint) Pacinian corpuscles on top of nerves (deep) tactile corpuscles (superficial) Nails- protective coverings on ends of fingers and toes, keratinized epithelial cells. Hair follicles- tube like depressions containing a group of epithelial cells that give rise to a hair. Apocrine- respond to emotion or pain, scent associated (areas with lots of hair) Skin thins, less collagen and elastin leads to wrinkles, age spots, wound healing slows, hair whitens and growth slows, trouble controlling temperature. Inflammation: normal response to injury or stress, blood vessels dilate and become more permeable.
