Burns 101 Biology Video Lecture | Introduction to Burn Care: Medical Treatment - Health & Fitness

proper evaluation of the acute burn
whether in the emergency department or
in the
patience setting requires an
understanding of the pathophysiology of
burns in this segment we'll discuss the
different types of burn and show
examples of different types of burn
severity we'll also discuss a triage
system for basic triage of acute burns
the skin is the largest organ in the
human body it has two layers a thin
cellular epidermis derived from ectoderm
which overlies a thicker dermis made up
primarily of extracellular matrix and
derived from mesoderm the layers of the
epidermis include the basal layer
stratum spinosum stratum granulosum
stratum lucidum and stratum corneum
other important cells in the epidermis
are melanocytes which provide pigment
that protects skin against ultraviolet
radiation and Langerhans cells which are
phagocytes and antigen presenting cells
compared to keratinocyte regeneration
melanocytes replacement is slower and
more unpredictable thus even superficial
burns can leave permanent changes in
pigmentation the dermis is in turn
composed of two layers itself the
papillary and the reticular dermis cells
of the dermis are primarily fibroblasts
which produce a highly ordered matrix of
collagen and elastin fibers of collagen
and elastin course through the ground
substance which is a mixture of
glycosaminoglycans and proteoglycans
unlike the ectodermal epidermis the Mesa
dermal dermis cannot regenerate after
infancy and instead heels by scarring
and fibrosis when heated proteins in the
skin are denatured and cells lose the
integrity of their membranes the amount
of damage is proportional both to the
temperature of the burn and to the
duration of contact with the heat source
the classic burn presents with three
zones of injury the zone of coagulation
in the center of the wound where all the
cells have died the zone of stasis with
a mix of living and dead tissue
vasoconstriction and ischemia and the
zone of hyperemia populated with viable
cells the zone of coagulation is beyond
repair and the zone of hyperemia
generally will survive but only through
careful management of the wound and
the patient's comorbidities can the zone
of stasis be salvaged burns heal when
epithelial cells within undamaged
follicles on the healthy edges of the
wound migrate over the surface of the
wound these epithelial cells can divide
and travel up to one centimeter to cover
the burned area these newly Aurea
pathologized burns are fragile though
and new epithelium is prone to blister
and desk women