Chapter 04: Healing P. 63-70: 75-76 Flashcards
what is healing?
restoration of structure, strength and sotimes function
Most oragns are formed by?
parenchyma
What are parenchyma bound together by?
supported by connective tissue and blood vessels that combine to form the stroma
What is the process called when tissue is replaced by parenchyma?
regeneration
what is the process called when replaced by fibrous scar tissue?
repair
cells lost through injury may be replaced by ___.
mitosis
why is regeneration ideal response to tissue lost?
new tissue assumes normal functions
what are the three types of regeneration patterns?
labile
stable
permanent
what is the fx of labile tissue?
must divide continually to replace cells that are constantly being depleted by normal processes
what is an example of liable tissue?
epethila of the skin
what is the function of stable tissue?
cells divide, but slowly, when normal development is complete
stable tissue can ___ their mitosis rate when damaged tissue must be replaced.
increase
what are examples of stable tissue?
osteoblast, smooth muscle fibers, and vascular endothelium
what is the significant factor of regenration?
can produce tissue with nearly normal function or with some degree of functional loss
what is the pattern of permenant regeneration
loss of permanent tissue usually results in functional loss
what is an example of permenant tissue tissue?
nervous and cardiac tissue
what is the process of healing by repair?
laying down fibrous connective tissue to restore strength and structural integrity of damaged tissue that cannot regenerate
strong callogen rich replace,ent tissue forms a ___.
scar by process of fibrosis
what cell is specialized to form callogen fibers?
fibroblast
where is fibroblast present?
in CT of oragns stroma
what is the fundamental subunit of collagen?
procollagen
how long is collagen weak?
for about 5 post injury days
then it will gain strength
how does collagen gain its strength?
cross linking with adjascent fibers
where does the process of scarring occur?
ECM
what are the two elastic fibers contained in the ECM?
glycoproteins and proteoglycans
what are glycoproteins made of?
protein and small number of sugar units
what are proteoglycans made of?
proteins and dominant carbohydrate unit
whar is the former name of proteoglycans?
muccopolysaccharides
what is plasma fibrinigen get converted into?
fibrin
what does fibrin form at the site if injury?
mesh that entraps blood cells and tissue debris
what is the gelled mesh known as?
clot
what is the removal of the clot by phagocytosis known as? as?
organization
whar is the production of new blood vessels to supply and drain the site of damage?
revascularization/angiogenesis
what color does exudate take when blood vessels develop at damaged site?
pink and granular appearance
What is the pink granular tisssue called?
granulation tissue
What is repaired dependent on?
granulation tissue
what does lumen formation involve?
enlargement, mitosis, and vacuolation
what restores nervous control of the new vessels?
revacularization links to vasomotor neurons
how does surface restoration occur?
newly formed cells migrate across the wound surface
how is surface restoration possible?
epithelial tissue is labile hence readily able to supply replacement cells by mitosis
what is primary healing by first intention?
wound edges lie close together
what is the maximum strength a scar will receive?
70-80 % after 3 months
what is an example of primary healing wound?
surgical incision
what are characteristics of secondary healing?
edges are not closely oppsed
ex. wound in gastrointestinal tract
what specialized cell is onnly found in secondary healing?
myofibroblast
What characteristic does a myofibroblast exhibit?
contractile capability
possibly from pericytes
how do myofibroblast align themselves?
contract in a direction of right angles to the wound margin
what is contracture?
newly formed callogen demonstrates an exagerrated wound contraction as it matures
pronounced tissue distortion
give an example when contracture would occur?
would follow after burns to the skin
what is a stricture?
occurs on the walls of tubular organs
give an example of when stricture would happen?
infertility in females is the result of stricture that follows veneral disease
what is an adhension?
joining of serous membranes
what is the major effect of adhensions?
restriction of movement in structures that must move freely
what is dehscnce?
is the breaking open of a wound
what is the MC site of dihescent wounds?
abdominal wall
what is another factor that would contribute to dehscence?
any comprimise of callogen formation
such as defiency of vitamin C
what is a herniation?
displacement of a body organ from its normal position
what is a keliod?
irregular masses of scar tissue that protrude from the surface of the skin
what produces keliods?
the release of TGF-B (transforming growth factor beta)
what is proud flesh?
the over of granulation tissue
what is the the condition, proud flesh, somtimes referred to as?
exuberant granulations
