Integumentary SystemMichelle Mason, Hunter Eisenhower, Micaela Lincoln, Liam Murray

What is the integumentary system? Organ system that protects the body

from damage Guards the body’s physical and

biochemical integrity Functions:

Waterproof, cushion, and protect deeper tissues, excrete waste, regulate body temperature, attachment point for sensory receptors, vitamin D synthesis

The Skin The skin is the body’s integumentary

system Largest of the body’s organ systems 12% - 15% of body’s weight Is composed of a minimum of 3 layers:

Epidermis Dermis Hypodermis

Epidermis Outermost layer composed of epithelial

cells Composed of 4 layers: stratum basale,

spinosum layer, stratum granulosum, stratum corneum

Has no blood supply and depends on diffusion from dermal cells for metabolic needs

Stratum Basal Bottom most layer responsible for constantly

renewing epidermal cells Contains one row of undifferentiated columnar

stem cells that divide frequently Half of the divided cells move to the next layer to

begin the maturing process Other half stays in basal layer and divides over and

over to replenish basal layer Contains melanocytes: the cells responsible for

creating melanin, the pigment responsible for skin color

Spinosum Layer Cells transferred here change from

columnar to polygonal Cells begin to synthesize keratin

Keratin is the key component in making up the outer layer of skin, along with hair and nails.

Stratum Granulosum Cells here have lost their nuclei and are

characterized by dark clumps of cytoplasmic material

Here keratin proteins and water-proofing lipids are produced and organized

Stratum Corneum Cells here known as coreocytes and have

flattened out Cells here are composed of mainly

keratin protein which add strength but also allow absorption of water

Responsible for integrity and hydration of skin

Disruptions in this layer can result in a variety of skin problems

Dermis 2 Layers

Stratum papillare Stratum Reticulare

Dermis layer responsible for: Cushioning body Sense of touch

Made up of Collagen Elastic Fibers Hair Follicles

Stratum Papillare Makes up upper part of dermis It forms the sharp, wave shaped border

of the dermis The wavy surface increases the contact

with the epidermis Made of loose connective tissue Connects the dermis to the epidermis

Stratum reticulare Makes up a lower part of the dermis

Much thicker then the papillary The protein fibers give the layer

Strength Extensibility Elasticity

Contains Roots of hair, sebaceous glands, sweat

glands, receptors, nails, and blood vessels

Hypodermis Sometimes referred to as the

Subcutaneous layer and the superficial fascia

The lowermost layer of the integumentary system

It contains larger blood vessels and nerves than those in the dermis

A major storage site for adipose tissue

Contents of The Hypodermis Cells

Fibroblasts Adipose Macrophages

Subcutaneous Fat Layer of insulation to hold in heat Assists in Homeostasis

Accessory Structures of the Skin Sudoriferous and sebaceous glands Hair and hair follicles Nails

Sudoriferous and Sebaceous Glands Sebaceous Glands: (oil glands) found

surrounding hair follicles and deposit sebum, oily substance that lubricates the hair and skin, onto the hair shaft

Sudoriferous glands: (sweat glands) located in the dermis and secrete a watery substance that is important in body temperature regulation and excretion Four types: Eccrine, apocrine, ceruminous,

and mammary glands

Eccrine & Apocrine Glands Eccrine Glands: major sweat glands of the

human body; products contain mainly water, salts, and nitrogen-containing wastes

Apocrine Glands: don’t become active until after puberty; found only in the axilla, genital area, and areolae of the nipple; products contain lipids and proteins

Ceruminous & Mammary Glands Modified suderiferous glands Ceruminous Glands: Found in ear canal.

Produce a waxy substance (cerumen) that prevents foreign substances from entering the auditory canal.

Mammary Glands: Found in breasts. Synthesize and secrete milk after appropriate hormonal stimulation.

Integumentary Illnesses Sunburn Athlete’s foot Albinism Acne Herpes Blisters Rashes

Souces http://

en.wikipedia.org/wiki/Integumentary_system http://

www.emc.maricopa.edu/faculty/farabee/biobk/biobookintegusys.html

http://www.britannica.com/EBchecked/topic/189836/epidermis

http://www.skin-science.com/_int/_en/topic/topic_sousrub.aspx?tc=SKIN_SCIENCE_ROOT%5EAN_ORGAN_REVEALED%5ETHE_DERMIS&cur=THE_DERMIS

http://en.wikipedia.org/wiki/Subcutaneous_tissue