Term
| With tissue atrophy, there are (fewer/smaller) cells |
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Definition
| both! atrophy can mean fewer cells or smaller cells |
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Term
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Definition
| normal cells in an abnormal location |
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Term
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Definition
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Term
| What does "megaly" imply? |
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Definition
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Term
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Definition
failure to form an organ / produce the cells
e.g. born with only 1 kidney |
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Term
| What is differentiation? give an example |
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Definition
cells developing more specialized functions
e.g. pluripotent cells -> myeloeblast -> neutrophils OR eosinophils |
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Term
| Differentiated cells have (more/less) proliferative capacity |
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Definition
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Term
| What factors regulate cell number & size? |
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Definition
Hormones (endocrine signalling)
Local growth factors (paracrine signalling)
Tissue demand (workload, nerve stimulation etc) |
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Term
| How does nuclear receptor signaling work? give an example of a hormone that may do this |
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Definition
-ligand binds to nuclear receptor in the cytoplasm
-transporter brings complex into nucleus
-complex binds to transcriptional response elements
-gene expression is altered
e.g. estrogen binding to estrogen response element in nucleus to promote gene expression |
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Term
| Failure of an orifice to develop |
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Definition
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Term
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Definition
| proliferation of cells in a disorganized, abnormal pattern |
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Term
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Definition
| new pattern, excessive & poorly controlled cell growth with abnormal differentiation |
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Term
| How is gene expression generally regulated? |
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Definition
-growth factor binds to membrane receptor
-signal transducer proteins are activated
-internal messengers activated transcription factors
-transcription factors alter gene expression (e.g. up/downregulate) |
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Term
| Name 3 examples of systemic/endocrine growth factors & cytokines |
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Definition
EPO
Insulin
TSH
TNG
IL-6
Epidermal Growth Factor |
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Term
| Name 3 examples of local/paracrine growth factors & cytokines |
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Definition
Fibroblast GF
Keratinocyte GF
Hepatocyte GF
Epidermal GF
TNF
IL-6 |
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Term
| How does erythropoietin work to increase blood oxygen? |
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Definition
1. Kidneys detect decrease in O2 concentration in blood
2. Promote EPO release
3. Receptors for EPO in bone marrow
4. Reponsee = increased RBC production
5. [O2] restored |
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Term
| What effect does hypoxia have on VEGF? |
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Definition
Normal: HIF-1alpha is oxygenated, becomes labile, is degraded
Low O2: HIF-1alpha not oxygenated
-HIF gene expression upregulated
-EPO & VEGF production increased
-EPO promotes erythropoiesis
-VEGF promootes angiogenesis
-increased blood delivery & O2 carrying capacity
-oxygenation of HIF-1alpha restored |
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Term
| Give an example of adaptive hypertrophy |
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Definition
Cardiac muscle cells can't replicate
Loss/damage to some cells will cause the others to enlarge (hyertrophy) to try and compensate
e.g. left ventricle may become hyertrophic if the aorta is partially obstructed, as it has to work harder to eject blood |
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Term
| Give an example of hormone-induced hyperplasia & explain how it happens |
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Definition
1. High dietary phosphorous & low calcium
2. Imbalance causes hyperplatic parathyroid gland cells
3. PTH secretion increases
4. Bone resorption increases
Other options: Iodine deficiency -> thyroid gland compensation |
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Term
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Definition
| hyperplasia of the keratinized layer of the epidermis |
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Term
| Give an example of hormone-induced atrophy |
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Definition
Shunts diverting blood from portal vein to the vena cava
-liver won't be stimulate by insulin, glucagon etc. bc these originate in the pancreas
-will see atrophy of the liver as it isn't being stimulated by the hormones |
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Term
| What is the difference between primary & secondary hypertrophic cardiomyopathy? |
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Definition
Primary: enlarged for no reason other than it just grew. Impairs heart function
Secondary: enlarged to compensate for other pressures being put on the system. e.g. renal failure = high BP = heart has to work harder = enlarged cells |
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Term
| Give an example of physiologic-induced atrophy |
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Definition
| Nerve damage = lack of neuronal stimulation to muscle = myocytes will shrink/become fewer in number |
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Term
| What are the requirements for a tissue do be able to return to normal? |
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Definition
-epithelium must be mitotically active
-connective tissue framework must be intact
-adequate vascular supply |
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