BIOL LAB INTEGUMENTARY SYSTEM

What is the thin superficial layer of the skin? epidermis

What is the thick deeper layer of the skin? dermis

What are the layers of the epidermis, superficial to deep? Stratum Corneum
-Stratum Lucidum (found only in thick epidermis)
-Stratum Granulosum
-Stratum Spinosum
-Stratum Germinativum/Basale

What is a function of the stratum germinativum/basale? It contains stem cells that replenish cells as superficial layers slough off

What does the Stratum Germinativum contain that dictates the color of our skin? The stratum germinativum contains special cells called melanocytes

What do melanocytes produce? Melanin

What is a function of the melanin? Absorbs UV radiation

What is the melanocyte activity of 1. people with pale ivory skin and 2. people with dark ebony skin?

1. Low melanocyte activity
2. High melanocyte activity

For those who have low melanocyte activity, skin color is determined by what two factors?

1. Carotene- orange pigment
2. Dermal blood supply- rosy appearance

How is the epidermis secured to the dermis? through a series of epidermal ridges and dermal papillae that act as a lock

Where are epidermal ridges/dermal papillae more prominent on the integument? Areas with high frictional stress-such as the sole of the feet

What happens when there is excess friction on the skin? The two layers (epidermal ridges and dermal papillae) separate and fill the space between with interstitial fluid thus creating a blister.

What does the dermis contain? Blood vessels, nerves, sensory receptors, extracellular fibers, hair follicles, and glands

How are blood vessels (arteries and veins) divided? They are divided by location (superficial to deep)

What protein are both hair and nails composed of? keratin

What is the basic function of the hair and nails? Protect the integument

What areas of the body is hair not found on? The soles of the feet, the palms of the hands, lips, and portions of the external genitalia

Describe the terminal hair and where it is found Typically long and thick
-Found on the head, eyebrows, eyelashes, and pubic regions

Describe the vellus hair and where it is found typically, short and thin
-vellus hair comprise most (75%) of the hair on the body

What is the function of the arrector pili muscle? Lifts the hair shaft upon nervous stimulation, which increases skin sensitivity

What is the function of the papilla? vascular structure that provides nutrients

What is the function of the matrix? location of new hair growth

What are the shaft layers superficial to deep? cuticle, cortex, medulla

What is the specific function of the nails? To strengthen the distal portion of the digits

What is the function of the nail matrix? Mitotically active zone of nail growth

Describe the lunula? It is the half-moon shaped region at the proximal end of the nail bed - newly formed and undifferentiated white cells of the nail body.

Describe the Eponychium Epidermal cells dragged forward along the body as the nail grows; otherwise known as the cuticle.

Describe the hyponychium Epidermal cells dragged beneath the body as the nail grows.

Where are the secretory glands located? The dermis of the skin

What are the four types of secretory glands? Sudoriferous Glands
-Sebaceous Glands
-Ceruminous Glands
-Mammary Glands

What is the function of the sudoriferous glands? To excrete sweat to regulate body temperature and eliminate waste products

What do eccrine glands excrete? Eccrine glands are found abundantly across the body and excrete mostly water.

What do apocrine glands secrete? Found in the armpits, groin, and surrounding the nipples, this gland produces a concentrated secretion of sweat

What do sebaceous glands secrete? An oily secretion called sebum (typically associated with hair follicles)

What do ceruminous glands produce? A waxy secretion called cerumen (found exclusively in the ear)

What do mammary glands produce? Milk - these glands are found in the breasts but only active in pregnant and nursing women

What is the general function of secretions? To cool, lubricate and protect the skin

The hypodermis is a ________ tissue that lays adjacent to the _____. connective, dermis

How does the content and distribution of the hypodermal adipose shapes affect appearance? The content and distribution of the hypodermal adipose shapes give each person a somewhat unique superficial appearance.

The hypodermis is typically quite _____ depending on the bodily location Thick

What can cause severe burns?—fire, electricity, radiation, and certain chemicals

What are the categories of burns? 1st, 2nd, and 3rd degree

Describe 1st degree burn—only burns the epidermis
-ex. sunburn

Describe 2nd degree burn—burns both epidermis and dermis
-most painful because of the pain receptors

Describe a 3rd degree burn—burns epidermis, dermis, and hypodermis
-painless because of the complete destruction of pain receptors (usually accompanied with second degree burn)

How do you estimate what % of the body is burned? Each major body region is