Cellular Adaptation & Gangrene (325E1) Flashcards
cell adaptation
changes that your bodies cells go through to permit survival and maintenance of cellular function, can change size or form (abnormal changes can occur)
atrophy
decreased or shrinking cell size (once a certain # of cells do this in a particular organ, the organ will be labeled atrophic)
atrophy: physiologic
related to a developmental issue (less common and usually at birth)
atrophy: pathologic
related to decreased workload or changed environmental conditions (broke right leg and now muscle doesn’t get used)
characteristics of atrophied cells
decreased protein synthesis (building) and/or increased protein catabolism (breakdown)
causes of cell atrophy
nutritional deficiencies, decreased blood supply, hormonal problems, prolonged immobility, aging
hypertrophy
increased in the size of the cell and can increase function (typically in response to mechanical stimuli)
examples of negative hypertrophy
growing of heart and kidney (heart in HNT pumps against higher resistance and the heart muscle gets bigger which isn’t goo)
examples of positive hypertrophy
a healthy adult who is working out and gaining muscle
hyperplasia
usually never a good thing increased number cells results from increased rate of cellular division response to prolong injury or severe injury (common in cancer & hormonal stimulation)
what are the only cells that have the ability to undo hyperplasia
cells with the ability to divide (skin spec. epidermal, intestinal epithelium, glandular cells)
when hyperplasia normal
-pregnancy related changes (lactating cells)
-wound healing
what can hyperplasia turn into
dysplasia (dys means wrong)
dysplasia
abnormal changes in size/shape/organization of mature cells (often associated w/ neoplastic growths aka cancer cells)
does dysplasia = cancer
no, it is a precursor to cancer
how can dysplasia be classified
mild, moderate, severe (is reversible)
what is dysplasia associated with
inflammation and chronic irritation
what cell adaptation is most associated with cancer
metaplasia (it can predispose to cancer)
metaplasia
reversible replacement of one type of mature cell to another (often the replacement is less specific (differentiated) to that area) ; allows cells to survive better in a hostile environment
what can metaplasia be a pathologic response to
chronic irritation and inflammation
neoplasia
cellular growth not responding to normal regulator processes (usually become gene mutations)
anaplasia (interchangeable w/ neoplasia)
cells differentiate to immature form or embryonic form (these are cancer cells and are associated with neoplasms & malignant tumors)
cancer
uncontrolled cellular growth with rapid uncontrolled proliferation and loss of ability of cells to differentiation
neoplasia: benign
reproduce more rapidly than normal cells but slower than malignant cells bc these are non cancerous (less anaplastic)
when do benign neoplasia cell cause problems
in areas that are sensitive to compression like the brain
neoplasia: malignant
reproduce rapidly with atypical cells, often metastasize (more anaplastic)
necrosis
cell death due to injury, disease, or failure of the blood supply
characteristics of necrosis
irreversible because it leads to swelling and inflammation then bursts the cell
ischemic necrosis
infarction (absence of blood supply)
what does prolonged ischemia lead to
gangrene
gangrene
dead tissue with bacteria (cannot fight the infection bc of lack of blood)
liquefactive necrosis
the burst cells can become liquid in tissues with lots of lipids (brain) or where there are numerous inflammatory cells
necrotic tissues becomes a breeding ground for what
bacteria
what are the most common sites for gangrene
lower extremities (disease associated are vascular diseases and DM)
dry gangrene
-black, dry, wrinkled
-minimal bacteria present (thin line between healthy & dead)
-slow spread (takes weeks-months)
-minimal inflammation
wet gangrene
-liquefaction (lots of damage)
-moist, no pulse, cold, swollen
-rapid spread
-can be systemic (cues: tachy, fever, confused)
-most common in fatty organs but can be in limbs
-foul smell
gas gangrene
-caused by clostridium perfringens d/t trauma or accidents w/ wounds & it destroys connective tissue & cell membranes
-anaerobic and spore forming
-gaseous bubbles
