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Anatomy and Physiology – Chapter 4: Skin and Body Membranes (Integumentary System)
Pages (109 – 130)
Body membranes, which cover surfaces, line body cavities and form protective (and often lubricating) sheet around
organs.
Classification of Body Membranes
 Epithelial membranes
* Cutaneous (skin)
* Mucous – (mucosa)
* Serous
- Serous fluid
- Peritoneum
- Pleura
- Pericardium

Connective tissue membranes
* Synovial membranes
- Bursae
- Tendon sheaths
Integument
Skin – the largest organ and is called the cutaneous membrane
Functions of the Skin
Layers of the Skin
 Epidermis – (outer layer) – avascular (has no blood supply of its own)
- keratinocytes – keratin cells – make up most of the epidermis
- has 5 layers called strata:
* stratum basale
* contains melanin
* stratum spinosum
* stratum granulosum
* stratum lucidum
* stratum corneum

•
Dermis – (middle layer) – your “hide” – sensory receptors, blood vessels, and glands
2 Major Regions
• Papillary Layer
• Reticular Layer
- Bedsores – decubitus

Hypodermis or Subcutaneous
Skin Color
• How skin color is determined
• Skin Color Alterations:
Appendages of the skin
 Cutaneous glands (sweat glands)
 Hair

Nails
Cutaneous Glands (exocrine glands)
 Sebaceous – (oil glands)
 Sudoriferous – (sweat glands)
- Eccrine – more numerous
- Aprocrine – axillary and genital areas
Hair
–
–
Protective Functions:
Produced by a hair follicle
• Root – encloses the hair in the follicle
• Hair bulb matrix
• Shaft
–
What are “Goose bumps”.
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A nail is a scale-like modification of the epidermis; similar to a hood or claw of other animals
Nail matrix is responsible for nail growth
• As nail cells are produced by the matrix, they become keratinized and die; so like hair, most is
nonliving material
Transparent and colorless, but look pink due to the rich blood supply in the underlying dermis
Nails
–
Homeostatic Imbalances of the Skin
 Allergies
o Contact dermatitis
 Infections
o Bacterial
 Boils and carbuncles
 Impetigo
o Viral
 Cold sores (fever blisters)
o Fungal
 Athlete’s Foot
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
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Acne
Psoriasis
Burns
Skin Cancer
• Types of Skin Cancer
– Basal Cell Carcinoma
– Squamous Cell Carcinoma
– Malignant
– ABCD Rule:
» Asymmetry
» Border Irregularity
» Color
» Diameter
Developmental Aspects of Skin