Question

1 You wear a pair of ill-fitting shoes and develop a blister, which occurs when the epidermis and dermis have become separated. it As the blister heals, you notice that the blister's "roof"-which is composed entirely of epidermis-consists only of dead skin. Why did the epidermis of the blister die? b While removing the dead epidermis, you notice that the blister is filled with clear fluid, but no blood. Why wouldn't you find blood in an epidemal injury? 2 The condition epidermolysis bullosa is characterized by repeated blister formation resulting from only minor trauma. Several forms of the disease are caused by mutations in genes coding for keratin proteins. Why would defective keratin lead to an inability to resist mechanical stresses?

Answer 1

The epidermis of a blister dies due to separation caused by friction and pressure from ill-fitting shoes. In an epidemal injury like a blister, blood is not typically found as the injury is limited to the epidermal and dermal layers. Defective keratin can lead to an inability to resist mechanical stresses, resulting in repeated blister formation.

Step-by-step explanation:

The epidermis of a blister dies because the constant friction and pressure from ill-fitting shoes cause the epidermal cells to separate from the underlying dermis. This separation disrupts the blood supply to the epidermal cells, leading to their death. As the blister heals, the dead epidermis sloughs off and is replaced by new, healthy skin.

In an epidemal injury like a blister, you wouldn't find blood because the injury is limited to the epidermis and dermis layers of the skin, which have minimal blood supply. The blood vessels are located deeper in the dermis, so the clear fluid filling the blister is primarily composed of plasma and other fluids.

Defective keratin can lead to an inability to resist mechanical stresses because keratin is a structural protein that provides strength and resilience to the skin. When keratin proteins are faulty due to gene mutations, the skin becomes more fragile and prone to damage, resulting in repeated blister formation even from minor trauma.

Answer 2

The epidermis of a blister may die due to disrupted blood supply and cell damage. An epidemal injury doesn't involve blood vessels in the outer skin layer. Defective keratin can lead to an inability to resist mechanical stresses, causing repeated blister formation.

Step-by-step explanation:

The epidermis of a blister may die because the separation of the epidermis and dermis disrupts the blood supply to the epidermis, leading to cell death. Additionally, the friction and pressure caused by ill-fitting shoes can cause damage to the cells, resulting in their death.

In an epidemal injury, you wouldn't find blood because the injury only affects the outer layer of the skin, which lacks blood vessels. Blood vessels are primarily found in the dermis, the layer beneath the epidermis.

Defective keratin can lead to an inability to resist mechanical stresses because keratin is a structural protein that plays a key role in maintaining the integrity and strength of the skin. When there are mutations in genes coding for keratin proteins, the skin becomes more fragile and prone to blister formation even from minor trauma.