Chapter 4—Integumentary System Skin and Body Membranes

What is a body membrane?? A sheet of tissue that does one of the following: 1.) Cover body surfaces 2.) Line body cavities 3.) Form protective sheets

What kind of membranes are in the body?? Epithelial Membranes made up of epithelial cells Ex.) Cutaneous, Mucous, Serous Connective Tissue Membrane made up of fibrous tissue Ex.) Synovial

Epithelial Membranes Cutaneous Outer layer (think skin) Mucous “Wet Tissue” lines open body cavities Serous lines closed body cavities

Cutaneous Membranes Characteristics: --Superficial Epidermis Layer --Made up of Stratified Squamous tissue --Contains Keratin becomes hard and waterproofed --Underlying Dermis Layer

Cutaneous Membrane

Mucous Membranes Characteristics: --Moist Tissue --Lines body cavities “open” to the exterior --Sheet of epithelial cells --Rests on Areolar Connective Tissue (called --Lamina Propria) --Has the ability to secrete and absorb

Mucous Membranes

Serous Membranes Characteristics: Lines “closed” body cavities ( in the Ventral Body Cavity) 1 Layer of simple squamous tissue Rests on Areolar Connective Tissue (called Lamina Propria)

Serous Membranes 2 Layers: Visceral (wraps around an organ) Parietal (lines the cavity)

Serous Membranes Found in three areas: PericardiumSerous membrane around the heart Pleura  Serous membrane around the lungs Peritoneum Serous membrane around digestive organs

Pericardium

Pleura

Peritoneum

Connective Tissue Membrane Synovial Membrane—body’s only connective tissue membrane --Found where two bones meet (Joint Articulation) --Fibrous joint capsule --Secretes Synovial Fluid to decrease friction

Synovial Membrane

Skin

Skin has 3 layers: Epidermis:  Outermost Layer  Does not have it’s own blood supply Dermis:  Supplies and Nourishes the Epidermis  Connective Tissue Layer Subcuataneous Fat Layer:  Made up of Adipose Tissue  Absorbs Shocks and Insulates the body  Anchors the skin down

Facts about your skin:  Major function is to Protect!  About as thick as a paper towel  Largest organ of the human body  Provides a covering for your body  Regulates heat loss and body temperature  Keratinized and Stratified

More Facts about your skin: Insulates and Cushions Deeper Structures Protects from Damage Ex.) bumps, bruises, chemical & thermal , UV and bacterial protections  Excretes wastes (through sweat)  Manufactures Vitamin D (when in sunlight)  Contains receptors that sense: touch, pressure, temperature & pain

Structure of the Skin: