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29 Cards in this Set
- Front
- Back
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what is this?
-same state -constancy of the internal environment, steady state, internal balance, a state of dynamic equilibrium -conditions under which the cell operates efficiently and maintains overall health -way in which the cells or systems of the body maintain stability while adjusting to changing conditions |
homeostasis
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homeostasis is maintained through negative feedback mechanisms:
-cells react to a change or disturbance in the environment through a series of modifications of ... size and ... direction to those that created the disturbance -cells act to .. or cancel out the changes that have occurred, restoring the proper balance to the cell |
equal
opposite negate |
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the whole point of homeostasis:
large external changes only make ... internal fluctuations inside |
small
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set point = ... condition, or ... values
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ideal
average |
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components of homeostatic control systems in body:
-sensor/receptor - ... -integrator/control center - ... -effector/responder - ... |
sensory receptors
brain muscles and glands |
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components of homeostatic control systems in a cell:
-sensor or receptor: could be a ... -control center: through a second messenger, it sends a signal to some protein or other mediator in the cell to decide what to do = specific ... of the cell or ... -effect: change in protein expression. Could change transcription or protein activity |
cell surface receptor
protein nucleus |
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stimulus --> receptor --> integrator --> effector --> response
the response to the stimulus leads to a change. the change is "..." to the receptor. In ..., the response of the system cancels or counteracts the effect of the original stimulus |
fed back
feedback |
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what are these?
-membrane potential -membrane transport, ion gradients -osmoregulation, cell volume -pH and buffers -energy production -protein and lipid biosynthesis -normal molecular turnover, housekeeping |
cellular processes under homeostatic control
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-blood pressure
-blood volume (osmoregulation) -body temp -blood glucose -oxygen/CO2 levels -rate of cell death vs. cell devision These are undergoing ... homeostasis |
systemic
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blood glucose level has a set point of about ... mg
above that is called ... below that is called ... |
90
hyperglycemia hypoglycemia |
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after eating, ... cells of the pancreas are stimulated to release insulin into the blood
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beta
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after skipping a meal, ... cells of the pancreas are stimulated to relase glucagon into the blood
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alpha
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what are these?
-illness and disease -cell death -aging |
what happens when homeostasis can not be maintained
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-think of an injury as a disruption in homeostasis
-... is the homeostatic control effort that seeks to return a cell back to a "stable state" and protect the cell from further injury. -most basic evolutionary survival response |
adaptive cell response
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types of cell injury:
-...: mechanical trauma, temp, pressure, radiation -...: drugs, toxins, metabolites -...: enzyme defects (genetic), cytokines and cell-mediated responses (immune system), microbial infections, deficiency of vital molecules (oxygen, glucose, vitamins, etc) |
physical
chemical biological |
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critical targets in cellular injury (things that we don't want to be impaired/injured):
-impaired ... production (mitochondria) -impaired cell ... function -...(DNA) alterations (mutations) -... derangements (enzyme) |
energy
membrane genetic metabolic |
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what are the 4 basic responses to cellular injury?
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ischemic/anoxic response
oxidative stress response heat shock response acute phase response |
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ischemic/anoxic response:
-changes in gene expression to promote ... glycolysis to maintain ATP -decreased total ..., with an increase in hypoxia-associated protein expression (e.g. glycolytic enzymes) -if response inadequate --> failure of membrane ..., membrane integrity lost, increased intracellular ..., death |
anerobic
protein synthesis ion pumps calcium |
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oxidative stress response:
-due to ... like superoxide, hydrogen peroxide, hydroxyl radical -no molecule is safe -damage to mitochondria, membrane lipids, proteins, and DNA -free radicals have an ... - that's what makes it so reactive -responses: proliferation, differentiation, adaptation, apoptosis |
reactive oxygen species (ROS)
unpaired electron |
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oxidative stress response: Antioxidants
-superoxide dismutase (SOD): converts SO radicals to less harmful forms -... (in lysosomes) -reduced glutathione(O2 acceptor)/glutathione peroxidase -vitamin ... and ... -metallothionein |
catalase
C E |
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heat shock response:
-involves .../chaparones -first discovered in response to heat, but actually induced by a variety of cellular insults (ischemia, oxidative stress, infection, heavy metal toxicity) -also referred to as "stress response" and "stress proteins" -provides adaptive advantage to stressed cells by increasing fidelity of protein synthesis and aiding in ... of damaged or denatured proteins |
heat shock proteins (HSP)
refolding |
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heat shock protein would be the receptor, integrator, or effector?
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effector
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How HSPs work:
... conditions --> detection of ... proteins --> ... are produced --> HSPs ... denatured proteins |
stressed
denatured HSPs refold |
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what is the response that the liver undergoes when there is some kind of damage in the body?
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acute phase response
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acute phase response:
-usually refers to dramatic change in pattern of ... protein synthesis in response to inflammatory cytokines -response is an outpouring of ... proteins that function to maintain homeostasis of other cells -acute phase proteins include C-reactive protein, fibrinogen, complement, haptoglobin and ferritin, plasminogen activator inhibitor |
hepatocyte
plasma |
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what protein is this?
-binds phosphorylcholine on microbes, assists in complement binding, and enhances phagocytosis |
C-reactive protein
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-high CRP is associated with ... and considered a risk factor for diabetes, hypertension, cardiovascular disease, maybe cancer
-we don't know if it's the cause or effect |
systemic inflammation
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C-reactive protein blood test:
-low risk: <# mg/L (normal) -high risk: ># mg/L -high levels indicate general inflammation, but doesn't indicate where or why -high CRP could result from infection, IBS, lupus, rheum. arthritis, colon cancer, heart disease (false positive during pregnancy and when taking oral contraceptives) |
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if homeostasis is not maintained, it can lead to cell ...
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DEATH!!!
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