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69 Cards in this Set
- Front
- Back
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Molecules in the extracellular fluid can function as messenger molecules. These molecules:
A. Function as hormones. B. Function as neurotransmitters C. Function to provide cell to cell communication. D. All of the above |
D all of the above
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What type of molecule requires channels to pass through cell membranes, lipid soluble or water soluble?
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water soluble
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Do lipid soluble molecules work slowly or quickly?
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slowly, 2-24 hours
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Lipid soluble material passes through cell membrane and binds to an _______________. The " "-ligand binds to ______ and thus turns on _______ synthesis.
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intracellular receptor
DNA mRNA |
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What 2 things to water soluble molecules do to a cell?
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Pass through a channel
Bind to surface receptors -couple directly to ion channels -couple to coupling proteins (G proteins) -Couple to autophosphorylation activated receptors |
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What 3 enzymes does arachadonic acid split up into?
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cyclooxengenase
lipoxygenase epoxygenase |
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What do you get from cyclooxengenase?
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prostaglandins
thromboxanes prostacyclin |
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What do you get from lipoxygenase?
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HETEs
leukotrienes |
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What do you get from epoxygenase?
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epoxides
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Material acts on a receptor that is linked to an enzyme or channel through a coupling protein-
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G proteins
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What toxin is a good example that involves the inhibitory protein Gi
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Pertussis toxin directly inactivates the inhibitory coupling protein
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What increases adenylyl cyclase activity and therefore increases the intracellular concentration of cAMP?
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Gs protein
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What toxin activates Gs?
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cholera
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What breaks down cAMP?
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phosphodieterases
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What are examples of phosphodiesterases?
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caffeine and theophylline
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What do phospholipases release?
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arachidonic acid
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What is sPLA2?
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phospholipases that are secreted
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What is cPLA2?
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phospholipases that are in the fluid of the cell
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What are leukotrienes and what do they do?
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They are fatty signaling molecules. Function: trigger contractions in the smooth muscles lining the trachea; their overproduction is a major cause of inflammation in asthma and allergic rhinitis.
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________ inhibits phospholipase A2.
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Cortisol
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What pain relief medication isn't a COX inhibitor?
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acetaminophen/tylenol
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What do COX inhibitors increase the risk of?
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Probability of renal and GI problems and with the exception of low doses of aspirin heart attacks and strokes.
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All cyclooxygenase inhibitors increase lipooxygenase products that may cause _______
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asthma
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What does the phospholipase C hydrolysis of phospholipids proudce?
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diacylglycerol and phosphates of the phospholipid head group.
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Hydrolysis of PIP2 produces: 2 things
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inositol trisphosphates and diacylglycerol
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Diacylglycerol activates the enzyme:
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protein kinase C
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What does Protein kinase C do?
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phosphorylates many proteins including the proteins involved in regulating cellular division.
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What does inositol trisphosphate do?
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release calcium from intracellular sources and causes calcium to enter the cell. This increases intracellular calcium which regulated cellular activity.
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Explain autophosphorylation
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When these receptors bind to a substance, the receptor or receptor complex becomes phosphorylated which permits the receptor to modify the activity of other intracellular enzymes.
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What is an agonist, give an example
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a chemical that binds to a receptor and causes the same cellular effects as the natural substance is called an agonist.
Acetylcholine |
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What is an antagonist?
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A chemical that binds to a receptor but has no effect on the cell. Because antagonists bind to the reecptors, other chemicals cannot bind to the receptors. Thus, receptor antagonists are receptor blockers.
Ex: animal venoms |
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What are the products of glycolysis?
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pyruvate
2 ATP 1 NADH |
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What are the products of the Kreb's cycle?
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Citrate
2 CO2 GTP, NADH, FADH2 |
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What can alter cell and tissue biology?
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adaptation, injury, cancer/neoplasia, aging, death
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What are normal changes to the tissues?
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callus, tan, uterus and breast changes during pregnancy, adrenal glands grow larger under stress
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What are abnormal changes to the tissue?
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cell death due to burn, mole or wart, cataracts, cancer
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atrophy
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smaller cells
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hypertrophy
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larger cells
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hyperplasia
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more cells
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metaplasia
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replacement of one cell type by another cell type. Often the new cell type is not as differentiated.
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Dysplasia (atypical hyperplasia)
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cells lose normal organization, shape, and size. This is often a pre-cancer condition
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What is hypoxia?
What causes it? |
lack of oxygen to the tissues.
blockage of blood flow due to poor circulation (heart failure), low BP, blockage of a blood vessel with a clot, occlusion of blood vessels due to pressure injury, lack of proper oxygen in the atmosphere or a failure of the respiratory system |
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What changes start to occur with hypoxia?
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aerobic -> anaerobic
lactic acid levels increase production of ATP decreases ion pumps stop working cells swell and organelles become damaged |
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What happens with ATP in the cells during hypoxia?
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low ATP, broken down to ADP, then AMP, then adenosine; adenosine leaks out of the cells and is metabolized; cell gets oxygen again and can't make ATP due to lack of adenosine
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Adenosine synthesis is a very _____ process that may require ___ hours to return a cell to normal adenosine concentrations following hypoxia.
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slow
72 hours *thus full damage caused by hypoxia is often not evident until 24-48 hours following the hypxia |
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What is reperfusion injury
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excess blood flow, excess oxygen in the tissues -> highly reactive oxygen is produced which cause membrane damage
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Bacterial endotoxins/ lipopolysaccharides are produced by gram-________ bacteria.
LPS causes increased production or __________. *specific or non-specific? |
negative
cytokines non-specific |
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What are produced by gram-positive bacteria?
What does it target? |
exotoxins
specific molecules or processes |
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What do bacterial enzymes do?
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digest the host cell
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What is bacteremia/septicemia?
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growth of bacteria in the blood, destroy blood cells, increase in cytokines, decrease in BP results
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Viral replication?
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as a virus replicates, it turns cellular components of normal cells into more viruses
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What does radiation do to cells?
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excites atoms which can break the bonds between atoms and thus cause a molecule to become unstable
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What kind of molecules does radiation target?
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large molecules like DNA,
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What kind of cells are most affected by radiation?
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rapidly growing cells: GI cells, cells of a fetus, bone marrow cells, lymph node cells, skin cells, and cells associated with the hair follicle
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Small amounts of radiation consequences
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primarily affect DNA
little to no cell death mutations in cells can cause cancer or genetic mutations effects are long-term |
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consequences of moderate radiation
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causes sufficient DNA damage to cause slow cell death (days to years)
sores develop that do not heal or heal slowly if sufficient cell death has occured the patient may die |
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consequences of large amounts of radiation
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cause damage to RNA and DNA
large burn-like sores develop one to two days later the tissue in the area of exposure dies quickly patient dies of several days |
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consequences of extreme radiation
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destroys protein, RNA and DNA
tissue rapidly develops a burn-like sore the patient dies within seconds to days |
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Temp extremes:
heat- cold severe cold |
heat-denatures proteins
mild cold-like hypoxia decreases ATP severe cold-ice punctures cells |
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mechanical trauma of cells
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cells destroyed by pressure or cutting of the cell membrane. Cellular destruction releases molecules which are pro-inflammatory
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Manifestations of cellular injury: 6 things
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1. cell swelling due to inhibition of the ion pumps
2. increase entry of calcium into the cell. High concentrations of calcium are toxic to the cell 3. swelling of endoplasmic reticulum and shedding of ribosomes 4. swelling of mitochondria 5. accumulation of lipids, carbs, calcium etc. in the cells or tissue 6. disruptions of nuclear membrane and autolysis occurs if cells die |
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What are the five types of necrosis?
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coagulative
liquefactive caseous fat necrosis gangrenous necrosis |
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coagulative necrosis
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denatured material is gelatinous to a firm opaque
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liquefactive necrosis
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dead tissue is walled off and becomes a liquid
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caseous necrosis
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cottage cheese like appearance of tissues generally caused by TB, found in soft tissues of the body
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fat necrosis
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lipids of the cell break down. These lipids combine with calcium ions to form soap. The tissue is firm and has a chalk like appearance
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what are the 3 types of gangrene, give the symptoms
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dry-tissues dry, wrinkle, become dark, found in areas of poor blood flow. Coagulative necrosis results
wet-found in areas of good blood flow. Neutrophils invade the tissue and produce a liquefactive necrosis. Tissue is red and inflamed gas- clostridium infection of injured tissue. bubbles of foul-smelling gas are produced by the bacteria and a foul odor results. Increase in cytokines, cardiovascular collapse can result. |
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How do you treat gangrene?
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Keep it sterile to prevent infection, use moist, sterile bandages
Remove dead tissues Give antibiotics hyperbaric chamber to promote wound healing |
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Define apoptosis
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programmed cell death, natural process, occurs in ovary, during development (webbed fingers), production of specific T and B lymphocytes, immune system kills cells infected with a virus or cancer cells
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