Accessory Organs Found in the Skin and Their Functions

Touch Receptors Merkel Cells – Small disc shaped cells found in the stratum basale that respond to gentle physical sensation Very few of them found in the body, but are concentrated in sensitive areas

Touch Receptors Meissner’s Corpuscles – Nerve receptors surrounded by a club-shaped pile of connective tissue that sense touch in the demis

Touch Receptors Pacinian Corpuscles – Large oval structures with many layers found in the hypodermis that sense hard pressure and vibrations

Touch Receptors Pain Receptors – Free nerve endings throughout the epidermis that sense physical damage

Touch Receptors Hair Receptors – Free nerve endings that detect changes in hair position

Nail Structure Nails are layers of keratinized stratum corneum cells Provide protection for your fingertips and aids in small movements Grows from the nail root underneath the cuticle and pushes cells further out into the nail body

Hair Anatomy Made up of dead keratinized epithelial cells Hair Shaft Hair Follicle: Hole in the skin where hair develops Hair Bulb: Expanded base of the root Hair Papilla: blood vessels that project into the base of the hair to provide it with nutrients Arrector pili muscle: contract to allow hairs to stand up straight

Sweat Glands Apocrine sweat glands Located near the hair follicles, groin, and armpits Become active around puberty and act as a sexual attractant Eccrine sweat glands Located all over your skin Regulate body temperature

Sebaceous Glands Oil glands that keep the skin from drying out Destroys pathogens on the skin as well

Temperature Regulation in the Skin To Cool Down: Vasodilation More blood pumped to extremities Sweating To Warm Up: Vasoconstriction More blood retained in the core Goose Bumps Shivering