Integumentary System Lab Quiz Notes PDF

**Information to know for Lab Quiz on Integumentary System** **[Integumentary System Model]** Be able to identify the following structures and know their functions: **[Epidermis:]** thin, outer layer of stratified squamous epithelium **[Dermis:]** thicker, inner layer of connective tissue, blood...

**Information to know for Lab Quiz on Integumentary System** **[Integumentary System Model]** Be able to identify the following structures and know their functions: **[Epidermis:]** thin, outer layer of stratified squamous epithelium **[Dermis:]** thicker, inner layer of connective tissue, blood vessels, smooth muscle, and nervous tissue **[Hypodermis (subcutaneous layer):]** - Layer underneath dermis, consisting of areolar and adipose tissues - Binds skin to underlying tissues, but is not part of the skin - Adipose tissue insulates to conserve body heat - Contains major blood vessels that supply the skin **[Hair follicle: ]** - Each hair develops from epithelial stem cells at the base of a tube-like depression - Hair follicles dip down into the dermis or sometimes the subcutaneous layer **[Sebaceous gland:]** - Secrete an oily substance called sebum, that waterproofs and softens the hair and skin - Holocrine glands; entire cells filled with secretion are released - Associated with hair follicles **[Eccrine gland:]** merocrine glands that respond to body temperature; more abundant type; many found on forehead, neck, back; secrete onto skin surface **[Apocrine gland:]** merocrine glands (incorrectly named) which become active at puberty; respond to fear, emotional upset, pain, or sexual arousal; most numerous in axilla and groin; sweat contains proteins & fats that produce body odor; secrete into hair follicles **[Pacinian corpuscle (aka, lamellated corpuscle)]**: Meissner's corpuscle (aka, tactile corpuscle) free nerve endings **[Arrector pili:]** - A bundle of smooth muscle cells, - attaches to each hair follicle; when it contracts in response to cold temperature or emotional upset, it causes goose bumps **Know the types of tissues present in each layer of the skin** the epidermis, made of closely packed epithelial cells, and the dermis, made of dense, irregular connective tissue that houses blood vessels, hair follicles, sweat glands, and other structures. **Know the function of sebum and keratin and melanin** **[Sebum]** acts as a natural moisturizer, keeping the skin soft and supple by creating a protective barrier **[keratin]** forms the structural protein that makes up the outer layer of skin, providing a waterproof barrier **[melanin]** is a pigment produced by cells called melanocytes, giving skin its color and offering protection from harmful UV rays from the sun.