In which skin layer a chemical substance 'eleidin' is found-

Correct Answer: B

Rationale: The correct answer is B: Stratum lucidum. Eleidin is a protein-rich substance found in the stratum lucidum, the clear layer of the epidermis located between the stratum corneum and stratum granulosum. This layer is characterized by its translucent appearance due to the presence of eleidin, which helps to provide waterproofing and protection to the skin. The stratum germinativum (A) is responsible for cell proliferation, the stratum granulosum (C) is where keratinocytes undergo apoptosis, and the stratum corneum (D) consists of dead keratinocytes and serves as a barrier to external factors.

Correct Answer: D

Rationale: The correct answer is D: The blood flow to the skin increases. When a fair-skinned person is sunburned, the body increases blood flow to the affected area to help with healing. This increased blood flow causes the skin to appear red due to the dilation of blood vessels near the skin surface. Choices A, B, and C are incorrect because a decrease in blood supply, an increase in red melanocytes, or an increase in production of red pigments do not directly explain why the skin turns red after sunburn.

Correct Answer: D

Rationale: The correct answer is D: sebaceous gland. Sebaceous glands are holocrine glands, where entire cells are released with their secretions. The sebaceous glands produce sebum by the disintegration of entire cells, a characteristic of holocrine secretion. A: Merocrine glands release secretions through exocytosis, not by disintegration of cells. B: Ceruminous glands produce earwax and are classified as modified apocrine glands. C: Apocrine glands release secretions along with a part of the cell cytoplasm, not the entire cell.

Correct Answer: B

Rationale: The correct answer is B: cutaneous membrane and accessory structures. The integumentary system consists of the cutaneous membrane (skin) and accessory structures like hair, nails, and glands. The skin is the main component responsible for protection, sensation, and temperature regulation. The accessory structures support these functions. A: epidermis and superficial fascia - The epidermis is a layer of the skin, not a component of the integumentary system. Superficial fascia is a layer of connective tissue beneath the skin. C: cutaneous membrane and hypodermis - The hypodermis is a subcutaneous layer beneath the skin, not a component of the integumentary system. D: integument and hypodermis - The integument is another term for the skin, not a separate component. Hypodermis is not a component of the integumentary system.

Correct Answer: B

Rationale: The correct answer is B: Terminal. Terminal hairs are coarse, pigmented hairs found on the scalp, eyebrows, and eyelashes. This type of hair is fully developed and thicker compared to vellus hairs found on other areas of the body. Keratinous (A) refers to the protein that makes up hair, so it is not describing the type of hair. Follicular (C) pertains to the hair follicle itself and not the type of hair. Dense (D) does not specify the characteristics of the hair, so it is not the correct choice. Therefore, B is the correct answer.