Integumentary and Skeletal System Study Notes
1. Layers of the Skin
Epidermis (Outer Layer – Stratified Squamous Epithelium)
| Layer | Structure | Function |
|---|---|---|
| Stratum Basale | Single layer of stem cells, melanocytes | Cell division, skin regeneration, melanin production |
| Stratum Spinosum | Several layers of keratinocytes | Keratin production, immune defense (Langerhans cells) |
| Stratum Granulosum | Flattened keratinocytes with granules | Waterproofing, cells begin to die |
| Stratum Lucidum | Thin layer of dead cells (thick skin only) | Extra protection (palms & soles) |
| Stratum Corneum | 20–30 |
Essential Skincare Ingredient Glossary and Functions
Ingredient Types and Functions
Understanding ingredient categories is key to building an effective routine. Here are the main types:
- Humectant: Draws moisture to the skin from the environment or deeper layers. Best for dry or combination skin. E.g., hyaluronic acid, glycerin, etc.
- Emollient: Softens and smooths the skin by filling in cracks, leaving a silky feel. Best for mature, dry, or sensitive skin. E.g., squalane, silicones, etc.
- Occlusives: Prevents water loss (TEWL) by forming a barrier. Ideal
Essential Dermatology: Skin Lesion Definitions and Chronic Conditions
Common Chronic Skin Conditions
- Xerosis (Dry Skin)
- Pruritus (Itching)
Primary Skin Lesions
Types of Primary Lesions
- Macule
- Patch
- Papule
- Plaque
- Nodule
- Tumor
- Wheal
- Vesicle
- Bulla
- Pustule
Definitions of Primary Lesions
Macule
Small, flat, non-palpable lesion, **≤ 1 cm** in diameter.Patch
A large macule, flat, non-palpable lesion, **> 1 cm** in diameter.Papule
Small, elevated, solid lesion, **≤ 0.5 cm** in diameter, with no visible fluid.Plaque
Larger, elevated, solid lesion, **> 0.5 cm** in diameter. Can be a
Comprehensive Human Anatomy: Integumentary, Muscular, Skeletal Systems
I. Integumentary System: Functions
Physical Protection: The Skin Barrier
Prevention of Injury: The skin’s tough outer layers protect the body from physical trauma and injury. The epidermis, particularly the stratum corneum, provides a thick, durable layer.
Protection from Pathogens: The skin acts as a barrier to harmful microorganisms. Keratinocytes in the epidermis provide resistance to penetration, while Langerhans cells detect and initiate immune responses against invaders.
Protection from Harmful
Endocrine Hormones and Skin Anatomy Facts
Essential Facts about Hormones and the Integumentary System
The Endocrine System: Hormones and Their Functions
The endocrine system relies on hormones produced by various glands to regulate critical bodily functions. Below is a summary of key hormones, their source glands, and primary actions.
Major Hormones and Glands
- Estrogen: Controls the development of female secondary sex characteristics (Ovary).
- Testosterone: Controls the development of male secondary sex characteristics (Testes).
- Calcitonin: Decreases
Forensic Analysis of Sharp Force Trauma Wounds
Wounds Caused by Cutting Instruments
Wounds caused by cutting instruments are defined by the existence of a thin blade and a triangular section edge (_filo_). True cutting instruments include: knives, razors, scalpels, etc.
Mechanism of Action
The edge penetrates the tissue like a wedge, dividing it and producing solutions of continuity.
Characteristics of Incised Injuries
Incised injuries typically fall into three types: linear wounds, flap wounds, or wounds resulting from oblique penetration.