Healing By Primary Intention Flashcards Preview

Healing By Intention > Healing By Primary Intention > Flashcards

Flashcards in Healing By Primary Intention Deck (6)
Loading flashcards...

What occurs during seconds - minutes of injury?


Severed arteries contract -> Narrow space fills with clotted blood -> Dehydration of surface clot and scab forms, acting as a natural dressing.


What happens within minutes to hours of injury?

Inflammation - Triggered automatically without waiting for bacteria.

Neutrophils appear at margins to ward off bacteria.

If a wound is kept sterile, the leukocyte count is not high enough to to be considered pus.


What happens before 48 hours after injury?

Migration of Cells.

Macrophages appear and scavenge dead neutrophils -> Secrete cytokines to attract cells like fibroblasts and endothelial cells -> Basal epidermal cells meet in middle underneath scab


What happens three days after injury?


Macrophages replace neutrophils -> Granulation tissue (fibroblasts and new capillaries) invade space -> Epithelial cells proliferate, thickening epidermal layer -> Epidermal cells undermine scab so it falls off -> Angiogenesis progresses


What happens 7-10 days after injury?

Early scarring.

Wound is filled with fibres which form a fibrous mass -> epidermis keratinises but skin appendages don't form -> White cell infiltrate, oedema and increased vascularity disappear.


What happens 1 month - 2 years after injury?

Scar maturation.

Scar has many collagen fibres, few cells and few elastic fibres so little recoil -> As capillaries disappear, old scars appear white.