Body Membranes & Skin

Epithelial Membranes  3 Types  Cutaneous  Mucous  Serous

Cutaneous Membrane  SKIN!  Exposed to air and is a dry membrane

Integumentary System  Made up of skin and its components such as sweat, oil, glands, hair, & nails.

Functions of the Integumentary System  Protection  Regulate Body Temperature  Insulates & Cushions  Makes Vitamin D  Prevents Water Loss

Structure of Integumentary System  2 Types of tissues:  Stratified Squamous (epidermis)  Dense Connective Tissue (dermis)  Blister: Forms when the epidermis and dermis separate from each other.  Subcutaneous Tissue: Adipose tissue deep to the dermis. Serve as a shock absorber & insulates deeper tissue.

Formation of a Blister

Epidermis  Avascular (Men can shave skin layers daily and not bleed!)  5 Layers (Deep  Superficial) 1. Stratum germinativum (basale) 2. Stratum spinosum 3. Stratum granulosum 4. Stratum lucidum 5. Stratum corneum (Thickest layer)

Epidermis still…..  Melanin: Pigment which ranges in color from yellow to brown to black.  Produced by cells called melanocytes.  Found in the Stratum germinativum.

Dermis  Papillary  Upper dermal region  Have dermal papillae  Fingerprints  Reticular  Deepest skin layer  Contains blood vessels, sweat & oil glands

Red face after running?  Blood vessels become engorged and move to the surface of the skin to cool off and regulate body temperature.

Skin Color  3 Pigments contribute to skin color:  Amount of Melanin: (yellow, red, brown, black…)  Amount of Carotene: (orange, yellow)  Amount of Oxygen in hemoglobin

More Skin Color…  Erythema: Blushing  Blanching: Pale Ghost (Vasorestriction)  Jaundice: Yellowing of Skin  Hematoma: Bruise

Hair, Nails, & Burns

Hair Structure  Hair Bulb  Root  Medulla: inner central core  Cortex: surrounds medulla  Shaft: projects from the skin  Cuticle: outermost layer; covers cortex) Arrector Pili: Muscle that is attached to hair follicle (goosebumps)

Hair Types  Wavy Hair: Hair shaft is OVAL  Curly/Kinky Hair: Hair shaft is FLAT or RIBBON-LIKE  Straight Hair: Hair shaft is perfectly ROUND

Nail Structure  Free Edge  Nail Plate (top)  Nail Bed (underside)  Lunula  Nail Fold (Cuticle)  Nail Matrix

Burns  Rule of Nines: Divides the body into 11 areas each accounting for 9% of total body surface.  Head = 9%  Chest and abdomen = 18%  Upper/mid/low back and buttocks = 18%  Each arm = 9%  Groin = 1%  Each leg = 18% As an example, if both legs (18% x 2 = 36%), the groin (1%), and the chest and abdomen (18%) were burned, this would involve 55% of the body.

Burns  Burns are serious because victims lose fluids and this affects all body systems.  Skin is sterile for 24 hours after a severe burn, but after that bacteria and fungi begin to invade.

1 st Degree Burns  Only the epidermis is damaged  Area is red & swollen  Usually heals within 2- 3 days  Ex. Sun burns

2 nd Degree Burns  Involves injury to the epidermis & upper dermis region  Skin is red with painful blisters  Regeneration of the epithelium can occur  Usually no permanent damage

3 rd Degree Burns  Destroys the entire thickness of skin  Burned area appears blanched (gray/white)  Not painful b/c nerve endings are destroyed  Regeneration is not possible (skin graphing)