Epithelial Membranes

•3 Types•Cutaneous•Mucous•Serous

Cutaneous Membrane

•SKIN!•Exposed to air and is a dry membrane

Mucous Membrane

•Lines all body cavities that open to the exterior.•They are wet/moist membranes that are almost continuously bathed in secretions.

Serous Membrane

•Lines body cavities that are closed to the exterior.•Occur in pairs (Visceral & Parietal)

Visceral & Parietal?

•Visceral Serosa: The covering that touches the organ.•Parietal Serosa: The outer covering that does NOT touch the organ•The 2 layers are separated by a clear fluid called serous fluid.

The prefix “Peri-”…

•Means “to cover”•Ex: Peritoneum: Covers organs of the abdominal cavity.

Pericardium: Covers the heart

(exc.) Pleura: Covers the lungs

Connective Tissue Membranes

•Synovial Membrane•Composed of connective

tissue•Contain NO epithelial cells•Found surrounding your

joints•Provide a smooth surface

and secrete lubricating fluid

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)

•Subcutaneous Tissue: Adipose tissue deep to the dermis. Serve as a shock absorber & insulates deeper tissue.

(hypodermis)

Formation of a Blister

Blister: Forms when the epidermis and dermis separate from each other•Friction/burns•Separation fills with interstitial fluid

Epidermis•Avascular (Men can shave skin layers daily and not bleed!)•5 Layers (Deep Superficial)

1. Stratum basale2. Stratum spinosum3. Stratum granulosum4. Stratum lucidum5. Stratum corneum (Thickest layer)

Bottom

Top

Stratified squamous

Keratinized

Layers of the Epidermis

“Bio Students Graduate Less Crazy”

Epidermis still…..

•Melanin: Pigment which ranges in color from yellow to brown to black.•Produced by cells called melanocytes.•Found in the Stratum basale.

Dermis (dense connective tissue)

• Papillary•Upper dermal region•Have dermal papillae•Fingerprints• Identifying films of sweat

• Reticular

•Deepest skin layer•Contains blood vessels, sweat & oil glands•Nerve endings•Pain receptors•Touch receptors

Dermis….continued

Contains:1. Collagen•Toughness of skin•Attract and bind water for skin hydration

2. Elastic Fibers•Skin elasticity•Decreases as age increases….leads to

sagginess and wrinkles

Hypodermis

•Deep to dermis •Not part of the skin•Anchors skin•Adipose tissue

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 Contributions to skin color:

1. Melanin: (yellow, red, brown, black…)2. Carotene: (orange, yellow)3. Amount of Oxygen in hemoglobin

Skin color conditions

•Erythema: Blushing•Blanching: Pale Ghost (Vasorestriction)•Jaundice: Yellowing of Skin•Hematoma: Bruise