مقارنة مقاومة الجلد لأشعة الشمس فوق البنفسجية - كتاب أنظمة جسم الإنسان - الصف 12 - الفصل 1 - المملكة العربية السعودية

3. أي البشرتين أكثر مقاومة وتنظيمًا لكمية أشعة الشمس فوق البنفسجية المخترقة للبشرة، شكل (1) أم (2)؟ ولماذا؟

99

وزارة التعليم Ministry of Education 2023 - 1447

--- SECTION: 3 --- 3. أي البشرتين أكثر مقاومة وتنظيمًا لكمية أشعة الشمس فوق البنفسجية المخترقة للبشرة، شكل (1) أم (2)؟ ولماذا؟ --- SECTION: Page Number --- 99 --- SECTION: Ministry of Education Logo and Dates --- وزارة التعليم Ministry of Education 2023 - 1447 --- VISUAL CONTEXT --- **DIAGRAM**: شكل (1) أم (2) Description: The diagram presents two distinct cross-sections of skin, labeled '1' on the right and '2' on the left, illustrating differences in pigmentation. Both sections show an upper epidermal layer and a lower dermal layer. Within the epidermal layer, 'الخلايا الصباغية' (pigment cells) are visible, with extensions reaching into the surrounding cells. 'الميلانين' (melanin) granules are shown as small dots within these cells. Section 1 (right side): Represents lighter skin. The pigment cells are present, but the melanin granules are less dense and appear more concentrated around the pigment cells themselves, with fewer granules distributed throughout the upper epidermal cells. The overall coloration of the upper epidermal layer is lighter. Section 2 (left side): Represents darker skin. The pigment cells appear more numerous and active, with a significantly higher density of melanin granules. These granules are widely distributed throughout the epidermal cells, extending further into the upper layers of the epidermis. The overall coloration of the upper epidermal layer is darker. Both sections show the underlying dermal layer, which appears similar in both, indicating the primary difference is in the epidermal pigmentation. X-axis: N/A Y-axis: N/A Data: Comparison of melanin density and distribution in two different skin types (1 and 2) to illustrate their varying resistance and regulation capabilities against UV radiation. Context: This diagram is used to answer question 3, which asks to identify which skin type (1 or 2) is more resistant to UV radiation and why, based on the visual representation of melanin content and distribution.