1. Membranes
Anatomy Ch. 4 Section 1

2. Functions of Body Membranes
Cover surfaces
Line body cavities
Form protective sheets around organs
Form lubricating sheets around organs
Fall into 2 major groups which are classified by tissue make up:
Epithelial
Cutaneous
Mucous
Serous
Connective
Synovial

3. Cutaneous Membrane The skin
Epidermis composed of stratified squamous epithelium
Dermis is composed of composed of dense connective tissue
Subcutaneous layer is composed of adipose tissue
Held to underlying organs by loose connective tissue
The only dry membrane because it is exposed to the air.

4. Mucous Membranes (Mucosa)
Most mucous membranes contain stratified squamous, simple columnar, or pseudostratified epithelia.
Rests on a loose (areolar) connective membrane called the lamina propria.
Lines all the body cavities that open to the outside.
Found in the respiratory, digestive, urinary, and reproductive tracts.
Wet membranes
Function in absorption or secretion

5. Serous Membranes (Serosa)
Simple squamous epithelium
Rests on thin areolar (loose) membrane
Line body cavities that are closed to the exterior
Occur in pairs forming 2 layers around organs. It is actually one membrane that folds on itself.
The 2 layers are separated by serous fluid.
The serous fluid allows organs to slide past each other and against cavity walls easily.

6. Two layers of serous membranes
Parietal: lines the wall of a body cavity
Visceral: covers the organs in the cavity
Examples of serous membranes
Peritoneum: lines abdominal cavity and organs
Pleura: lines the lungs
Pericardium: lines the heart

7. Mucous membranes line body cavities
open to the exterior.

8. Serous membranes line body cavities closed to the exterior.
Parietal
peritoneum
Parietal
pericardium
Visceral
peritoneum
Visceral
pericardium
Visceral
pleura
Parietal
pleura
Serous membranes line body cavities
closed to the exterior.

9. Synovial Membranes No epithelial tissue
Soft areolar (loose) connective tissue
Surround joint cavities
Provide a smooth surface and secrete a lubricating fluid called synovial fluid
Line bursae and tendon sheaths, both of which cushion organs that move against each other during muscle activity.
A bursae is a fluid filled sac found between bones and tendons
A tendon sheath surrounds a tendon which connects muscle to bone.

10. Joint cavity (contains synovial fluid) Ligament Articular (hyaline)
cartilage
Fibrous
capsule
Articular
capsule
Synovial
membrane