D eep w ou nd healing • Figure 4.7
When a cut or tear extends into the
dermis, blood vessels get torn. Once
blood clots form, various cells move in
to repair the damaged area by removing
damaged tissue and microbes, building
connective tissue matrix, and making
new epidermal tissue.
( Blood clot forms that fills
and seals the open wound.
I Epithelial cells migrate into
wound and proliferate.
I Fibroblasts begin to migrate
along fibrin threads into wound
Vasodilation (widening of
blood vessels) delivers
immune cells to wound.
Immune cells (neutrophils,
monocytes) migrate into clotted
wound and digest microbes and
Blood vessel walls grow,
reseal the vessels, and
restore normal blood flow.
T uH t l ogeth^ r In both types of wound ^
healing, which type of cell first migrates
into the wound?
Clot turns into
Epithelial cells bridge the
wound beneath the scab.
Fibroblasts lay down collagen
fibers and glycoproteins within
the wound to form scar tissue.
The Skin Plays a Number of Roles in the Body
p r o c e ss