1. Chapter 4: Skin and Body Membranes
Pages

2. What are Body Membranes?
Layers of tissues that serve to:
Cover body surfaces
Line body cavities
Form protective sheets around organs
Membranes are classified according to tissue types
If you think about the function of a tissue, you can figure out where you’ll find specific membranes
© 2015 Pearson Education, Inc.

3. Classification of Body Membranes
There are two major membrane systems:
Epithelial Membranes
Connective Membranes
There is a pattern to membrane arrangement, especially around organs
Once you remember the pattern, you can predict the specific arrangement
© 2015 Pearson Education, Inc.

4. Functions of Membranes
Epithelial membranes- these cover or line
There are three groups:
Cutaneous membranes
Mucous membranes
Serous membranes
Connective tissue membranes- cushion, line/cover, lubricate to prevent friction
Synovial membranes

5. Epithelial: Cutaneous Membranes
This is your skin
a dry membrane
Two main layers: epidermis and dermis
Epidermis: (superficial)
Composed of stratified squamous epithelium
Dermis: (lies deep to the epidermis)
Mostly dense, fibrous connective tissue
the basement membrane
© 2015 Pearson Education, Inc.

6. • Sebaceous (oil) gland • Hair follicle • Hair root
Figure 4.3 Skin structure.
Hair shaft
Dermal papillae
Epidermis
Papillary
layer
Pore
Appendages of skin
• Eccrine sweat gland
• Arrector pili muscle
Dermis
Reticular
layer
• Sebaceous (oil) gland
• Hair follicle
• Hair root
Hypodermis
(subcutaneous
tissue)
Cutaneous vascular plexus
Nervous structures
• Sensory nerve fiber
Adipose tissue
• Lamellar corpuscle
• Hair follicle receptor
(root hair plexus)

7. Epithelial: Mucous Membranes
Epithelial layer that rests on a connective tissue layer
lamina propria: Underlying loose connective tissue that forms the basement membrane
Mucous membranes line all body cavities that open to the exterior body surface
Mouth/nose, esophagus, digestive tract, bronchi
Wherever there is a need to absorb and/or secrete
© 2015 Pearson Education, Inc.

8. Figure 4.1b Classes of epithelial membranes.
Mucous Membranes
Mucosa of
nasal cavity
Mucosa of
mouth
Esophagus
lining
Mucosa of
lung bronchi
(b) Mucous membranes line body
cavities open to the exterior.

9. Epithelial: Serous Membranes
Lines open body cavities that are closed to the exterior of the body such as the:
Abdominal cavity
Thoracic cavity
(Exceptions are the dorsal cavity and joints)
Serous membranes occur in pairs
Pairs are separated by serous fluid
This arrangement allows organs to slide past one-another w/o friction

10. The Pairing System
Parietal layer: lines a portion of the wall of the ventral body cavity; like a perimeter lining
Visceral layer: covers the outside of the organ
This tissue is actually an extension of the parietal layer, but it folds back on itself to form the visceral layer
© 2015 Pearson Education, Inc.

11. Figure 4.1d Classes of epithelial membranes.
Outer balloon wall
(comparable to
parietal serosa)
Air (comparable to
serous cavity)
Inner balloon wall
(comparable to
visceral serosa)
(d) A fist thrust into a flaccid balloon demonstrates the
relationship between the parietal and visceral serous
membrane layers.

12. Specific serous membranes:
Peritoneum
Abdominal cavity
Pleura
Around the lungs
Pericardium
Around the heart
© 2015 Pearson Education, Inc.

13. Figure 4.1c Classes of epithelial membranes.
SEROUS MEMBRANES
Parietal
pleura
Parietal
peritoneum
Visceral
pleura
Visceral
peritoneum
Parietal
pericardium
Visceral
pericardium
(c) Serous membranes line body
cavities closed to the exterior.

14. Connective: Synovial Made only of connective tissue
Lines fibrous capsules surrounding joints:
Lines bursae
Bursae are sacs containing synovial fluid
Lines tendon sheaths
Tendon sheaths are an elongated bursa sac
Secretes a lubricating fluid to reduce friction
© 2015 Pearson Education, Inc.

15. Figure 4.2 A typical synovial joint.
Ligament
Joint cavity
(contains
synovial fluid)
Articular (hyaline)
cartilage
Fibrous
layer
Articular
capsule
Synovial
membrane

16. Bursa sac in the shoulder joint