Integumentary System Worksheet 1 - Free Printable

Based on the detailed analysis of the provided diagram of the human skin, here is the solution to the labeling task:

The image displays a cross-section of the skin, which is part of the integumentary system. The numbered labels point to specific anatomical structures.

- 1. Hair Shaft: This label points to the portion of the hair that is embedded within the skin, extending from the hair follicle up through the epidermis.
- 2. Hair Shaft: This label points to the tip of the hair shaft, which is the visible part of the hair that protrudes from the skin's surface. Both 1 and 2 refer to the same structure, the hair shaft, just different parts of it.
- 3. Epidermis: This bracket indicates the outermost layer of the skin. It is composed of stratified squamous epithelium and serves as the primary barrier against the external environment.
- 4. Dermis: This bracket points to the thick, middle layer of the skin, located beneath the epidermis. It contains connective tissue, blood vessels, nerves, hair follicles, and glands (like sweat and sebaceous glands), providing strength, elasticity, and nourishment to the skin.
- 5. Hypodermis (Subcutaneous Layer): This bracket identifies the deepest layer shown in the diagram. It is primarily composed of adipose (fat) tissue and connective tissue, serving as insulation, energy storage, and a cushion for the body.
- 6. Sebaceous Gland: This label points to a small gland attached to the hair follicle. It secretes sebum, an oily substance that lubricates the hair and the skin's surface, helping to prevent dryness and inhibit bacterial growth.
- 7. Arrector Pili Muscle: This label points to a small band of smooth muscle attached to the hair follicle. When this muscle contracts (often in response to cold or fear), it causes the hair to stand upright, resulting in "goosebumps."

In summary, the diagram illustrates the key components of the skin, from its protective outer layers to the underlying structures that support its function.