MT-healing Flashcards
most organs of the body are formed by “functional cells” called_____
parenchyma
parenchyma are bounded to together by connective tissue that forms the ______
stroma
When tissue is replaced from the parenchyma the process is called ______
regeneration
when fibrous scar tissue fills the gap left by the loss of damaged tissue it is called ____
repair
components of healing (4)
regenerationrepairrevascularizationsurface restoration
the formation of new ____ channels is important to healing
vascular
when cells lost through injury are replaced via mitosis of adjacent parenchymal cells….
regeneration
regeneration is and ideal response to injury because…..
new tissue assumes normal functions
not all tissues in the body possess the same degree of ______ capacity
regenerative
in terms of regeneration, there are 3 types of tissue
labilestablepermanent
_____ tissues must divide continually to replace cells that are being depleted by normal processes
labile
examples of labile tissue
skin, mucous membranes, linings of ducts, red bone marrow and lymphoid tissue
_____ tissue, regeneration involves accelerating the normal mitotic rate
labile
_____ tissue are those that divide slowly post adolescence
Stable
stable tissue examples
glandsliverosteoblastssmooth muscle fibersvascular endothelium
Regeneration in stable tissue is organized in a pattern dictated by the _____
stroma
disorderly regeneration process results in ______ tissue configuration typically involves ______ deficiency
abnormal, functional
in labile tissue the number of actively dividing cells is ___% or greater
1.5%
in _____ tissue, the number of dividing cells is less than 1.5%
stable
the loss of _____ tissue results in functional loss. this is because mitotic activity stops at ____
functional, birth
examples of permanent tissue
nervous tissuecardiac/skeletal muscle
permanent tissues are replaced by
scar tissue
stable cells can _____ the division cycle but only with the appropriate ______
reenter, growth stimulus
healing by____ is the process of laying down fibrous connective tissue
repair
repair restores _______ and _____ but not function
strength and structural integrity
scares are form by a process called
fibrosis
_____ cells make collagen fibers
fibroblasts
fibroblasts are present in the ___ tissue of the organs ____
CT, stroma
are resistant to damage
fibroblasts
fundamental subunit for formation of collagen
procollagen
procollagen + procollegen
long filament of collagen
long filament of collagen X many long filaments of collagen
collagen fiber bundles
newly formed collagen is weak until ___ days post injury
5
Cross linking of collagen fibers occur via ______ bonds between _____ fibers
chemical, adjacent
tensile strength of collagen matches that of
cast iron
tensile strength continues to increase in fibrous repair tissue after collagen production stops because….
it realigns it’s orientation along the lines of stress
extracellular matrix is where
process of scaring occurs
lots of protein with small carbo portion
glycoproteins
lots of carbs with little protein
proteoglycans (mucopolysacccharides)
ECM helps scar formation by
helping form a well anchored scar
plasma fibrinogen gets converted to ______, forming a _____ that entraps blood and tissue debris
fibrin, mesh
___ must be removed for healing process to be complete
clot
the elimination of the clot by phagocytosis (or necrotic tissue) and its replacement of scar tissue is called ______
organization
production of new blood vessels to supply and drain the site of damage is called
revascularization
______ occurs in the exudate at the damage site
revascularization
exudate takes on the characteristic pink and granular appearance, hence called ______ tissue
grannulation
_____ is dependent of the organization of the granulation tissue
repair
______ tissue is a transition material in which fibrosis and revascularization are favored
grannulation
new capillaries are formed from intact vessels _____ to the wound site
adjacent
dividing endothelial cells from adjacent capillaries project into the damaged area to form ______
endothelial buds (or cords)
vessel walls are built from the ______ _____
inside out
newly formed vessels are more
permeable
starts later and ends slower when compared to revascularization of blood vessels
lymphatic drainage
new endothelial buds of blood capillaries never link up with those coming from
lymphatic vessels
healing region has high
metabolic demand = more pink
links to vasomotor neurons develop and _____ nervous control of new vessels
restores
in surface restoration a zone of ______ developers near the wound edge.
active mitosis
primary healing describes healing of a
incision
clot functions
limits blood lossseals wound from dehydrationprotects agains microbesprovides stabilization for repair fibters
_____ digests the clot
macrophages via enzyme release
as macrophages digest the clot the ______ is released from RBCs and contribute to early discoloration
hemoglobin
granulation, revascularization and fibroblast activity start happening well with in
2 days
__ -___ days stitches are removed
6-8
resumption of _____ formation causes loosening of the scab, allowing it to easily separate from newly restored surface
keratin
melanocytes cannot ______ so they are not replaced (that is why the scar is lighter on the epidermis)
regenerate
the strength of fully healed skin never reaches its ______ level
preinjury
@ 5 days the new skin is ____ of original strength
10%
@ two months the new skin is ____ of original strength
1/3
@ 3 months the new skin is ____ of original strength
70-80% (max strength)
Secondary healing
is seen in wounds whose edges are not closely opposed
wounds that require secondary healing are _____ and _____
larger, produce more debris
secondary healing takes _____ than primary healing
longer
wound contraction
reduces the size of the gap the granulation tissue must fill and area the new epithelium must restore
mechanism of underlying wound contraction depends on a specialized cell called a _______
myofibroblast (has contractile capability while resembling a fibroblast)
myofibroblast start by _____ to other cells or fibrous structures at the margins of the wound
anchoring
a ____ wound leaves more surface to restore
circular
myofibroblasts align themselves so that they contract in a direction at ______ angles to the _______ center
right, geometric
when bone heals it forms new tissue and returns to _____ strength at point of damage
original
when the _____ is torn blood bleeds ino the surrounding tissue
periosteum
first stage of bone healing involves removal of ______ blood
clotted
initial stage of bone healing ______ migrate from the periostium and endosteium
osteoblasts
early second stage of healing_____ lay down dense collagen and cartilage resulting in a ______ mass
osteoblasts, fibrocartilaginous mass (akas soft callus/osteoid)
fibrocartilaginout mass provides _____ of the fracture
stabilization
______ is ossified by osteoblasts and forms a hard callus
osteoid (solf callus),
the third stage is _____ of the hard callus
remodeling
the third stage involves both _____ and _____
osteoblasts, osteoclasts
stage 1 ___ daysstage 2stage 3
4-5 days3 weeksmonths to years
damaged neurons are replaced by ____
gliosis
gliosis is the ____ of neuroglia
proliferration
no function is restored with partial or inadaquate axon ______
regeneration
the ____ only part of a myelinated neuros process is lost the damage the lost portion can regenerate is the supporting connective tissue and ______ remain intact along the original path of the neuron process
PNS, Schwann cells
regeneration of neurons cannot replace any _____ sensory receptors, this results in restoration of ____ but not _____
specialized, motor, sensory
when _____ connective tissue is lost throught injury the necessary guidance for the gowth of new sprouts is lacking and the _____ oft he axon or dendrite does not occur
nerve’s, regeneration
when an entire nerve is severed. regeneration of its neurons processes may occur if the _____ ends are aligned and promply sutured
opposite
if the nerve ends remain separated, the distal processes
degenerate
traumatic neuroma
disorganized tangle of axons and scare tissue that is usually quite painful
regeneration occurs in ____ muscle but not ____
smooth, skeletal
complication of healing
contractureadhesionsdehiscencekeloidsproud flesh
______ may limit mobility
contracture
______ is a contracture that constricts lumen of an organ
stricture (can even lead to stasis)
stricture of fallopian tube can lead to
sterility
stricture of intestines can lead to
perferation of the wall
Dehiscence
breaking up of a healing wound because of pressure
the abdominal wall is the most common site of ____
dehiscence
chances for dehiscence is greatly increased with ______
Paroxysms (coughing, vomiting, diarrhea)
dehiscence can lead to _____
hernia
Irregular masses of scar tissue
keloids
excessive release of ____ or super sensitivitiy can lead to keloid formation
TGF-B (transforming growth factor beta)
secreted by macrophages at site of injury
TGF-B (transforming growth factor beta)
TGF-B (transforming growth factor beta) function
proliferation of fibroblasts
overproduction of granulation tissue
proud flesh
when skin is pulled off with surgical material ____ which is normally at the surface of the skin is stuck deep into the dermis causeing
keratin, suture complications
cortico-steroids can _____ chances of infection
increase
movement near wound _____ or ____ healing
delays, prevents
non union or fibrous union occures when _____ is not ossified
osteoid
immobility is especially important for
muscle and tendon regeneration
animo acid _______ is required for normal healing because _____ need it for forming extra cellular matrix
methionine, proteoglycans
_____ is important for enzymes
zinc
AAs to procollagen needs
vitamin C
