This article provides answers to a review sheet on the Integumentary System. Please note that this is for informational purposes only and should not be considered a substitute for your own learning and understanding of the material. Always refer to your textbook and class notes for the most accurate and complete information. Also, remember that variations in answer phrasing are possible depending on the specific wording of the questions on your review sheet.
Key Functions of the Integumentary System
The Integumentary System, comprised primarily of the skin, plays a crucial role in maintaining homeostasis. Its key functions include:
- Protection: Acts as a barrier against physical trauma, pathogens, UV radiation, and dehydration.
- Temperature Regulation: Helps regulate body temperature through sweating and vasodilation/vasoconstriction.
- Excretion: Eliminates waste products through sweat glands.
- Sensation: Contains numerous sensory receptors that detect touch, pressure, temperature, and pain.
- Vitamin D Synthesis: Produces Vitamin D when exposed to UV radiation.
Layers of the Skin
The skin is composed of three main layers:
1. Epidermis
- The outermost layer, composed primarily of keratinized stratified squamous epithelium.
- Stratum corneum: The outermost layer of dead, keratinized cells. Provides the primary barrier.
- Stratum basale: The deepest layer, containing actively dividing cells (melanocytes are also found here).
2. Dermis
- A strong, flexible connective tissue layer containing collagen and elastin fibers.
- Houses blood vessels, nerves, hair follicles, and glands.
- Contains two layers: the papillary layer and the reticular layer.
3. Hypodermis (Subcutaneous Layer)
- Primarily composed of adipose tissue (fat).
- Provides insulation and cushioning. Not technically part of the skin.
Skin Appendages
Important structures associated with the skin include:
- Hair follicles: Produce hair, contributing to insulation and protection.
- Sebaceous glands: Secrete sebum, an oily substance that lubricates the skin and hair.
- Sweat glands: Produce sweat for temperature regulation and excretion. There are eccrine and apocrine sweat glands.
- Nails: Protective coverings on the fingertips and toes.
Skin Color
Skin color is determined by a variety of factors including:
- Melanin: A pigment produced by melanocytes, responsible for protection against UV radiation.
- Hemoglobin: The oxygen-carrying pigment in red blood cells.
- Carotene: A yellow-orange pigment found in the stratum corneum and subcutaneous fat.
Common Skin Conditions (Examples)
This section provides brief examples; a comprehensive list is beyond the scope of this review.
- Acne: Inflammation of sebaceous glands.
- Psoriasis: A chronic skin condition characterized by scaly patches.
- Skin Cancer: Abnormal growth of skin cells, various types exist (basal cell carcinoma, squamous cell carcinoma, melanoma).
Disclaimer: This is not an exhaustive review of the integumentary system. Consult your textbook and lecture notes for complete information. This information is for study assistance only and should not be used for diagnosis or treatment of any medical condition.
