Test: Anatomy and Physiology of Skin - NEET PG MCQ

Bullous pemphigoid is a chronic autoimmune skin condition characterised by:

• Large, fluid-filled blisters on the skin, primarily affecting older adults.
• Itching and discomfort, often preceding the appearance of blisters.
• Blisters that tend to form on areas such as the abdomen, groin, and armpits.
• The immune system mistakenly attacks the skin’s basement membrane, leading to separation of the epidermis from the dermis.

Management typically includes:

• Topical or systemic corticosteroids to reduce inflammation.
• Immunosuppressive agents in more severe cases.
• Regular monitoring and supportive care to manage symptoms and prevent complications.

The epidermis is the outermost layer of skin, serving as a protective barrier for the body. It plays a crucial role in safeguarding against environmental factors such as pathogens and harmful substances. Additionally, the epidermis is responsible for regulating moisture and provides a surface for the synthesis of vitamin D when exposed to sunlight. This layer is primarily composed of keratinocytes, which produce keratin, a protein that helps in maintaining skin integrity and resilience.

Situated between the stratum corneum and the stratum granulosum, it comprises degenerated cells.

The stratum corneum is the outermost layer of the skin, playing a crucial role in protecting the underlying tissues. It consists of dead skin cells that have undergone a process known as keratinisation. This layer serves several important functions:

• It acts as a barrier, preventing the entry of pathogens and harmful substances.
• It helps to retain moisture, thus maintaining skin hydration.
• It contributes to the skin's overall appearance and texture.

Overall, the stratum corneum is essential for skin health and integrity.

The stratum basale is the deepest layer of the epidermis. It plays a crucial role in the regeneration of skin cells by undergoing continuous division. This layer contains:

• Keratinocytes, which are responsible for producing keratin, a protein that helps protect the skin.
• Melanocytes that produce melanin, the pigment that gives skin its colour.
• Merkel cells, which are involved in sensation.

As new cells are generated, they move upwards through the layers of the epidermis, eventually reaching the surface and shedding off. This process is vital for maintaining healthy skin.

The letter B indicates the spinous layer, which features the most notable desmosomes.

Pemphigus is traditionally linked to autoimmune desmosomal dysfunction. Desmosomes are also crucial for mechanical intercellular communication through cardiac coupling, which strengthens cardiomyocytes. These structures are vital for maintaining proper cardiac function.

The papillary dermis is a layer of skin located just beneath the epidermis. It is composed of loose connective tissue, which provides structural support and elasticity. This layer contains a rich supply of blood vessels, lymphatics, and nerve endings, which play a crucial role in thermoregulation and sensation.

• The papillary dermis is primarily made up of thin collagen and elastin fibres.
• It houses dermal papillae, small, nipple-like projections that interdigitate with the epidermis.
• These projections increase the surface area for exchange of nutrients and waste products.
• Additionally, they contribute to the unique patterns of fingerprints.