Wound Healing and Fibroblast Function

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What is the primary function of fibroblasts in the healing process?

To migrate to the wound site and trigger an inflammatory response by releasing chemokines and cytokines.

To produce collagen and elastin fibers, thereby providing structural support and elasticity to the healing tissue. (correct)

To promote angiogenesis, the formation of new blood vessels, crucial for delivering nutrients and oxygen to the healing wound.

To directly engulf and degrade bacteria and cellular debris, playing a crucial role in clearing the wound of foreign material.

Which of the following accurately describes the role of the extracellular matrix (ECM) in wound healing?

The ECM is directly involved in the contraction of the wound, pulling the edges together for faster closure.

The ECM acts as a scaffold, guiding the migration of cells and providing a platform for the deposition of new tissue. (correct)

The ECM primarily serves as a barrier, preventing the entry of bacteria and other pathogens into the wound.

The ECM directly destroys invading bacteria and cellular debris, facilitating the cleaning of the wound.

Which of the following factors is crucial for the formation of mature collagen?

The presence of sufficient amounts of growth factors, such as FGF2 and TGF-β, to stimulate cell proliferation.

The sufficient presence of elastin fibers to provide elasticity to the healing tissue.

The availability of oxygen to facilitate the hydroxylation of proline and lysine residues. (correct)

The presence of adequate amounts of fibrinogen, a key component of blood clots.

What is the primary mechanism by which the wound undergoes physical contraction during the healing process?

The contraction of myofibroblasts, specialized fibroblasts with contractile properties. (A) Signup and view all the answers

What is the primary difference between healing by first intention and healing by second intention?

Healing by first intention occurs in wounds with minimal tissue loss, while healing by second intention occurs in wounds with significant tissue loss. (A) Signup and view all the answers

What is the main reason why the majority of vessels, fibroblasts, and inflammatory cells disappear from the wound site during the remodeling phase?

They undergo programmed cell death (apoptosis) or other cell death mechanisms. (D) Signup and view all the answers

Which of the following factors can contribute to the formation of hypertrophic scars or keloids?

All of the above. (D) Signup and view all the answers

Which of the following statements accurately describes the role of cytokines in the remodeling phase of wound healing?

Cytokines released by fibroblasts and epithelial cells regulate the production and breakdown of ECM components, influencing scar formation. (B) Signup and view all the answers

What characterizes the healing process of repair compared to regeneration?

It results in fibrosis and scarring through connective tissue proliferation. (D) Signup and view all the answers

Which cell type is characterized by the inability to regenerate after injury?

Permanent cells (B) Signup and view all the answers

What is a key feature of stable cells?

They lose proliferative ability after adolescence. (B) Signup and view all the answers

Which of the following is a role of growth factors in the healing process?

To facilitate tissue repair and regeneration. (A) Signup and view all the answers

How do labile cells respond to injury compared to permanent cells?

They can easily regenerate due to continuous proliferation. (D) Signup and view all the answers

What primarily hinders the regenerative capacity of permanent cells?

Their loss of proliferative ability around the time of birth. (C) Signup and view all the answers

Which factor does NOT influence wound healing outcomes?

The level of physical exercise before injury. (C) Signup and view all the answers

What is the main difference between regeneration and repair in tissue healing?

Repair leads to the formation of scar tissue while regeneration does not. (C) Signup and view all the answers

What is the primary function of angiogenesis during the wound healing process?

To create new blood vessels from existing ones (D) Signup and view all the answers

Which growth factor is NOT directly involved in stimulating endothelial cell migration during wound healing?

Platelet-Derived Growth Factor (PDGF) (A) Signup and view all the answers

What cell type is predominantly responsible for the synthesis of collagen in granulation tissue?

Fibroblasts (C) Signup and view all the answers

What characteristic describes granulation tissue during the healing process?

It appears pink, soft, and granular. (C) Signup and view all the answers

What role do integrins play in wound healing?

They facilitate cell adhesion and communication. (D) Signup and view all the answers

Which of the following local factors can impair wound healing?

Foreign bodies (A) Signup and view all the answers

Which of the following is NOT a component typically found in granulation tissue?

Necrotic tissue (A) Signup and view all the answers

How does collagen deposition contribute to wound healing?

It creates a framework for tissue repair. (A) Signup and view all the answers

What complication is characterized by the formation of excessive scar tissue within the boundaries of the original wound?

Hypertrophic scar (B) Signup and view all the answers

Which systemic factor is associated with poor blood supply affecting wound healing in elderly patients?

Advanced age (B) Signup and view all the answers

What happens to the newly formed vessels as healing progresses?

They are often degraded and become fewer. (D) Signup and view all the answers

What is the primary function of growth factors?

To stimulate cell division and proliferation (D) Signup and view all the answers

Which of the following conditions is least likely to be a complication of wound healing?

Favorable granulation tissue (D) Signup and view all the answers

What is the term for excessive granulation tissue that protrudes above the level of the surrounding skin?

Proud flesh (D) Signup and view all the answers

Which type of signaling occurs when a cell responds to substances it releases?

Autocrine signaling (D) Signup and view all the answers

What systemic condition can significantly delay wound healing due to altered blood supply?

Diabetes (B) Signup and view all the answers

What do fibrous structural proteins in the extracellular matrix primarily provide?

Tensile strength and recoil (C) Signup and view all the answers

What is the possible outcome of a wound healing complication termed Marjolin’s ulcer?

Development of squamous cell carcinoma (B) Signup and view all the answers

Which component is NOT typically found in the interstitial matrix?

Amorphous nonfibrillar collagen (D) Signup and view all the answers

What negative effect does ionizing radiation have on wound healing?

Delays granulation tissue formation (B) Signup and view all the answers

What is the role of adhesive glycoproteins in the extracellular matrix?

To connect matrix elements to one another and to cells (A) Signup and view all the answers

Which of the following best describes the basement membrane?

A network of amorphous nonfibrillar collagen closely associated with the cell surface (C) Signup and view all the answers

Which type of matrix is characterized by being present in spaces between various cell types, including epithelial and smooth muscle cells?

Interstitial matrix (B) Signup and view all the answers

What role do water-hydrated gels in the extracellular matrix primarily play?

Enabling hydration and swelling pressure (A) Signup and view all the answers

What primarily fills the wound space immediately after injury?

Blood (C) Signup and view all the answers

Which cells replace polymorphs by the 3rd day following an injury?

Macrophages (D) Signup and view all the answers

What is the first stage in the healing by second intention?

Initial haemorrhage (C) Signup and view all the answers

Which feature is characteristic of wound healing by second intention but not by primary healing?

Wound contraction (C) Signup and view all the answers

Which phase does granulation tissue formation occur in healing?

Organisation phase (A) Signup and view all the answers

What is the appearance of granulation tissue?

Deep red and granular (A) Signup and view all the answers

What signifies maturation of a scar during the healing process?

Decrease in vascularity (B) Signup and view all the answers

Which skin structures are not replaced during healing unless viable residues remain?

Sweat glands and hair follicles (B) Signup and view all the answers

Healing

The body's response to injury for restoring structure and function.

Regeneration

Replacement of damaged components restoring tissue to a normal state, often by cell proliferation.