Pathophysiology

Published by admin on

Identiy the 3 major parts of a cell
plasma membrane, cytoplasm, and nucleus
what is the function of the plasma membrane.?
major structural feture is the phospholipid bilayer, also contains recptors and pores , allow for material passage and ingegrity of the cells
what is the function of the cytoplasm?
jelly-like substance which differs from cell type . Cellular functions are performed in cytoplasm by organelles
what is the function of the nucleus?
absolutely necessary for the survival of the cell , also contains genetic information
what is the function of the mitochondria?
extracts energy in the chemical bonds which involves a series of chemical changes that relase the energy in small easily handled amounts which is released, captured and stored as ATP
what is the function of the ribosomes?
in protein synthisis they are the site of messenger RNA=ribonucleic acid, attachment and amino acid assembly in the sequence ordered by the genetic code carried by the RNA they ar snall rounded masses that are interconnected to cristernae.
what is the function of the smooth ER?
when the long parallel arrays of flattened membranes called cristernae are normally present in the cytoplasm
what is the function of the rough ER?
when the presence of ribosomes in the cytoplasm which are interconnected to the cristeranae
what is the function of the golgi?
small peices of GER membrane containing newly synthesized protein, pinch off from the GER and merge with the membrane of the golgi complex, storesit until it is needed, often carbohydrate or lipid is added to the stred protein to form a fully functional lproduct for secretion to pass to th cells exterior, vesicles lseperate from the golgi and move to the plasma membrane, merge with it, passing the secretion to the exterior where it may function locally or at some distant site to which a duct or the blood delivers it.
what is the function of lyosomes
freely distributed in the cytoplasm and consist of a membrane vesicle containing differnt enzymes which are capable of degrading or breaking down proteins and carbs, for this reason lysosome membranes must have chemincal properties that can resist the activities of the enzymes that they contain , without this resistance the enzymes would escape and destroy the cell of which tey are a part of.
what is the function of cytoskeleton?
it contributes to the cell including support and organization of the cells organelles and movement of materials within the cell b/c the cytoskeleton is attached to the plasma membrane, it also plays a role in maintaining cell structure and linking adajacent cells
what are 3 major causes of cell injury?
deficiency, intoxications, and trauma
examples of defciency of a cell
heart attack, or stoke, Oxygen deficiency, lack of B vitiamins and genetic defects-metabolic pathway disorders
examples of intoxications of a cell
infections, PKU (phenylketonuria) fom metabolic waste products , urea buildup in shock and billirubin, Carbondioxide, etc.
what are the functional reversible changes in cell injury?
altered metabolism (glycloysis vs. osygen), hypertrophy, hyperplasia, atrophy(pathologic and physiologic), apoptosis, cell stress proteins, organelle changes and hydropic degeneration
examples of trauma of a cell
hypothermia, hyperthermia, ionizing radiation forms free radicals, and physical trauma( breaks, sprains, )
discribe 3 irreversible cell changes
distorted PM-causes altred ion permeability (cellular swelling), decrease in mitochondria or lysosomes, cytoskeletion disrupted and nuclear changes
what are 3 types of nuclear changes?
Karyolysis=break in nucleus, Karyorrhexis =(fragmented), and Pyknosis=small , black, dead nucleus.
what happens if a cell has an irreversible change?, the cell passes what “point”?
if a cell has irreversible change (regardless of cause of injury) the cell will die, the point of no return.
what is meant by necrosis?
the condition of cell death
what is coagulation necrosis?
occurs in most tissues for a few days post-mortem(autolysis; boiled meat) cellular swelling
what is caseous necrosis?
characterized by cheesy exudate=the movement of fluid, suspended substances and cells
what is gangrenous necrosi
it is characterized by th presence of noxious products of anaerobic bacterial metabolism which can thrive without oxygen gain access to an area of damage they can proliferate in th owygen-deprived necrotic tissue.
what is liquefaction necrosis?
when coagulation does not occur. Instead nerotic tissue breakd down promptly,typically follows brain becrosis, it is possible that enzymes are able to resist denaturation long enough to produce a quick breakdown of the tissues, another occurance involves bacterial infections where microorganisims posses potent enzymes that quickly liquify necrotic cells.
what is calcifacation necrosis?
can occur in cells or tissues. Calcium depostion occurs especially in persistant injury or where damage effects are slow to develop, early injury that affects membrane function allows calcium into the cell. there it condenses in mitochondria to contribute to the cell’s death.
describe the characteristics of an acute inflammation. What is its suffix?
dramatic increase in blood flow to the injured tissue, swelling, pain and cellular response. (itis)
what are the cardinal sings of inflammation?
tumor(swelling), rubor(redness), calor(heat), and dolor(pain) added later is functio laesa(loss of function)
describe what inflammation is (a series of events, etc.)
a series of events, a coordinated activity, designed to be productive, and something that occurs only in living tissue.
where specifacally does inflammation occur?
in loose connective tissue
what are 2 phases of acute inflammation?
fulid phase and cellular phase
what is reactive hyperemia? What is the resulting fluid called?
is formation of transudate – more blood flow to injured tissue capillaries, increased hydrostatic prissure and relxation of precapillary sphincters (more fulid out of capillaries and this fluid is called transudate.
what do chemincal mediatiors do?
relased in response to tissue damage, many of these are positive feedback to increase vascular permability and allow fluid to escape and swell. ( associated with pain) ex; histamaines, serotonion, cyclooxygenase, prostaglandins and NO.
what are some possible benefits of fluid accumulation at the injury site?
dilution of toxins (causes less further damage), increased pain (allows disuse), prisence of antibodies from blood, and prisence of dilling proteins(complement) dills bacteria on contact, enhances inflammanation.
describe laminar blood flow through capillaris, axial.
blood flow is axial or laminar, along an axis, so that cells are in line with plasma on the outside. Plasma surrounds the cells which don’t touch the endothelial walls. benefits. this prevents inappropriate inflammatory of clotting responses
describe margination and pavementing, what does this process allow?
margination is during the reative hrpermia phase, blood flow slows down and in some cases stops, as a result, WBC’s tend to move toward the capillary walls. Pavementing= WBC’s adhere to the endothelial walls, this process causes the relase of more chemical mediators of inflammtion.
what is the result of chemotaxis? the resulting fluid is called?
migration of leckocytes to the inflammatory site and into the tissue spaces, the fluid evolves form transudate to exudate.
what are the first leukocytes in exudates? what is their role?
neurtophils are first to arrive at the site of inflammation (6-24) hours, the primary function is to eat bacteria.
which leukocytes move in later? when is their “peak time”?
macrophages arrive later to clean up around 2-3 days later.
how are 3 ways that inflammation can be classified?
duration (not often used), location (-itis), description of exudate.
describe 4 inflammations by description of fluid.
serous- only fluid escapes from capillaris (water+mucus), fibrinous- transudate, protin that forms blood clots, purulent or supportive- meutrophils= pus, diffuse cellulitis-subcutaneious tissue. and hemmorrhagic-blood escapes into tissues (fractures).
how long will chronic inflammation last?
greater than 6 weeks
describe chronic inflammation regardin amount of fluid and cells.
typically very decreased fluid, increased cells(usually macrophages and lymphocytes), cells dominate.
what can a small change in body temperature do to cells?
significantly alter cellular function(enzymw activity)
which organs are responsible for heat production and heat loss?
heat production= liver, heart, skeletal muscle and skin is about 90% of all heat loss, lungs = 10% heat loss by evaporation
what are the 4 methods of heat loss?
radiation, evaporation, conduction and convection
what is radiation?
heat energy moves directly away from warm skin surface ( direct loss)
what is evaporation?
water at skin surface is converted from liquid to gas consumming heat, energy from skin, causing temperature to fall.(via water loss)
what is conduction?
involves direct transfer of heat by physical contact between the body and cooler surrounding medium (transfer to a cooler medium)
what is convection?
when heat is carried away by movement of air or water surrounding the body.
what are 2 disorders of heat regulation? what is the major hyperthermic dispostion?
Hyperthermina= a loss of homeostatic control that results in rising body core temperature. Hypothermia= a core temperature below 95 degrees. The major predisposing conditon in heatsroke is dehydration.
how does the body respond when set points are raised or lowered?
in fever the temp regulation system increases the set point. when a new set point is set, the body’s responses are based on the new set point, when the set points returns to normal , body responses are then based on the lowered set point (sweating, throwing off bed covers, “fever breaks”),
what is the purpose of healing?
to restore structure, strenght and sometimes function, it is the next step in the progression after inflammation
what is regeneration?
occurs when uninjured parenchyma replaces what is lost, mainly liable tissues= which continually divide
what is repair?
if a tissue cannot regenerate, it is probably replaced by fibrous CT to restore strenght and structural integrity
what are the 4 major components of wound healing?
regeneration, repair, revascularization, and surface restoration
what is labile tissues?
they continually diivide (ex: skin epithellia, red bone marrow, some lymphoid)
what is stable tissues?
typically divide only slowly after adolescence, s ome have the capacity to regenerate if injured. (ex; mitotic cells, glands especially the liver, smooth muscle, fibroblast, endothelia)
what is permanent tissues?
not capable of mitosis, (ex; neurons, cardiac and skeletal muscle. usually damage= functional loss)
what is the name of the cell that is the primary cell in repair? what does it produce?
fibroblast and produces collagen fibers
what is granulation tissue? what does it contain?
occurs in loosley gelled, protein rich exudate tht forms at the damage site, as new blood vessels develop the exudate which takes on a characteristic pink in color and granular apperance
which type of wounds heal by primary healing? will they ever regain full strenght?
sterile surgical incisions or closely apposed sterile wound that can be sutured,No the strenght of fully healed skin although adequate never reaches it’s preinjury level.
define the types of wounds that heal by secondary healing?
wounds that are not clean, larger, or more than 6 hours old. (ex; GI ulcers, large skin wounds ) process is basically the same but may take longer due to infection or size.
describe 3 complications of healing
contractures, adhesions, and dehiscence
list some requirements for healing
age, murtition, immobility, blood supply, nutrients and clearance of debris
repair of tendon/ligament
can regenerate well if edges can be approximated. otherwise, scarring
repair of cartilage
scar tissue
repair of adipose tissues
can repace itself/regeneration
repair of lungs
can regenerate, but not if basement membrane is destroyed
repair of liver and kidneys
liver is highly regenerative. if parenchyma nd stroma are both lost , fibrosis (cirrhosis)
repair of kidneys
tubules can tegenerate, but nor glomeruli (also fibrosis)
repair of the parathyrod and adrena medulla
not regenerative
repair of nerves
nerve fibers and PNS can regenerate, but neurons are replaed by neuroglia
repair of muscles
scarring, but can hypertrophy
Categories: Pathophysiology