Skin Extra

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Questions and Answers

What role do Langerhans cells play in skin immune responses?

They produce histamine that causes inflammation.

They form a barrier that blocks allergens.

They execute cytotoxic actions against pathogens.

They act as antigen-presenting cells initiating immune responses. (correct)

How do mast cells contribute to allergic reactions in the skin?

They absorb allergens and neutralize them.

They produce antibodies specific to allergens.

They release inflammatory mediators like histamine upon allergen exposure. (correct)

They inhibit the production of self-antigens.

What is one consequence of inappropriate immune responses by Langerhans cells in autoimmune diseases?

Reduced skin hydration and barrier function.

Chronic inflammation and skin lesions. (correct)

Increased defense against external pathogens.

Enhanced production of skin cells leading to thicker skin.

Which immune cells are primarily involved in exacerbating inflammation during autoimmune conditions?

Mast Cells Signup and view all the answers

What common feature do allergic reactions and autoimmune diseases share in terms of immune response?

Both result in tissue damage and inflammation Signup and view all the answers

What type of skin graft includes the full dermis and hair follicles?

Full-thickness Skin Graft (FTSG) Signup and view all the answers

Composite grafts consist only of skin tissue.

False Signup and view all the answers

What is the primary purpose of skin grafts?

To cover wounds that cannot close on their own Signup and view all the answers

A Split-thickness Skin Graft includes the full dermis.

False Signup and view all the answers

A _____ Skin Graft relies on a vascularized bed to 'take.'

Split-thickness Signup and view all the answers

Match the following types of skin grafts with their descriptions:

Split-thickness Skin Graft = Includes partial dermis Full-thickness Skin Graft = Includes the full dermis and hair follicles Composite Grafts = Includes skin plus another tissue type Signup and view all the answers

Which type of burn affects only the epidermis?

First-Degree (Superficial) Signup and view all the answers

Second-degree burns can be both superficial and deep.

True Signup and view all the answers

What is a key characteristic of third-degree burns?

Painless due to nerve damage Signup and view all the answers

A second-degree burn that appears dry and is less painful is referred to as a ______ type.

deep Signup and view all the answers

Match the following burn types with their characteristics:

First-Degree = Very painful, no scarring Second-Degree superficial = Moist, blanches Second-Degree deep = Drier, non-blanching, less painful Third- and Fourth-Degree = Involves all skin layers, typically painless Signup and view all the answers

Study Notes

Autoimmune Diseases

Psoriasis and Lupus Erythematosus are examples of autoimmune diseases in the skin.
Immune system attacks skin cells, causing inflammation and lesions.
Langerhans cells, located in the epidermis, initiate immune responses and present antigens.
These cells can present self-antigens, triggering inappropriate immune responses in autoimmune diseases.
Mast cells release inflammatory mediators including histamine, contributing to tissue damage in autoimmune conditions.

Allergic Reactions and Hypersensitivity

Atopic Dermatitis and Contact Dermatitis are examples of allergic reactions in the skin.
Immune system mistakenly attacks allergens, leading to inflammation, itching, and redness.
Mast cells release histamine in response to allergens, resulting in inflammation, itching, and vasodilation.

Autoimmune Diseases

Psoriasis and Lupus Erythematosus are examples of autoimmune diseases that affect the skin.
These diseases are triggered when the immune system mistakenly attacks the body’s own skin cells.
This leads to chronic inflammation and skin lesions.

Immune Cells

Langerhans Cells are specialized immune cells located in the epidermis.
They act as antigen-presenting cells.
This means they initiate immune responses and contribute to the skin’s immune surveillance.
In autoimmune diseases, Langerhans Cells may present self-antigens, leading to an inappropriate immune response.
Mast Cells are found throughout the skin and release histamine and other inflammatory mediators.
In autoimmune conditions, Mast Cells can exacerbate inflammation and contribute to tissue damage.

Allergic Reactions and Hypersensitivity

Atopic Dermatitis and Contact Dermatitis are examples of allergic reactions.
Allergic reactions occur when the immune system responds to allergens, such as metals, chemicals, or environmental allergens.
This leads to inflammation, itching, and redness.

Mast Cells

Mast Cells are central to allergic reactions.
They release histamine upon encountering allergens, causing inflammation, itching, and vasodilation.
Vasodilation refers to the widening of blood vessels.

Skin Grafts

Used to cover wounds that cannot close on their own.
Three main types:
- Split-thickness Skin Graft (SSG): Includes partial dermis.
- Full-thickness Skin Graft (FTSG): Includes the full dermis, including hair follicles.
- Composite Grafts: Include skin plus another tissue type, such as muscle or cartilage.
Skin Grafts "Take" by the process of:
- Plasmatic Imbibition (0–48 hrs): The graft absorbs plasma from the recipient site.
- Inosculation (48–72 hrs): New blood vessels connect to the graft.
- Revascularization (~7 days): Full integration with the recipient blood supply.

Skin Grafts

Skin grafts are used to cover wounds that cannot close on their own.
Split-thickness Skin Graft (SSG):
- Includes only a portion of the dermis.
- Requires a vascularized bed (blood supply) to survive.
Full-thickness Skin Graft (FTSG):
- Includes the full dermis, including hair follicles.
Composite Grafts:
- Combine skin with other tissue types like muscle or cartilage.

Burn Classifications

First-degree burns affect only the epidermis, the outermost layer of skin. These burns are very painful but heal without scarring.
Second-degree burns extend into the dermis, the layer below the epidermis.
- Superficial second-degree burns are moist, blanch (turn white) with pressure, and are typically very painful.
- Deep second-degree burns are drier, do not blanch with pressure, and may be less painful.
Third- and fourth-degree burns are full-thickness burns, involving all skin layers, including subcutaneous fat, muscle, and even bone.
- These burns are typically painless due to nerve damage.
- They often require surgery for healing and may result in significant scarring and disability.