Integumentary (Dermis and Hypodermis) A&P

Functions

• Contains dermal papilla

• Binds epidermis to underlying tissues

• Contains sweat glands, oil glands, sensory receptors, and hair follicles

Papillary Layer

• First layer of dermis

• Thin and superficial

• Contain dermal papillase

• Made of loose areolar CT elastic fibers

• Attached epidermis to dermis

Reticular Layer

• Second layer of dermis

• 80% of dermis

• Made of dense irregular CT collagen fibers and elastic fibers

• Contains oil, sweat glands, fat, hair follicles

• Stretch marks occur here from tears in this region

Dermal Papilla

• Ridges in papillary region form finger prints

• Never change in your lifetime, form during second month of fetal development

Free Nerve Endings

• Basic

• Found throughout dermis

• Respond to temp change, tissue damage, and pain

Meissner’s Corpuscle Nerve Endings

• Attached to neurons

• Superficial in dermis (papillary region)

• Tactile, senses light touch

Pacinian Corpuscle Nerve Endings

• Deep in dermis (reticular region)

• Tactile sense deep pressure

Hypodermis

• Made up of Loose CT and Adipose

• Insulates

• Contains bigger/more major blood vessels

• Also known as subcutaneous (“under skin”)