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28 Cards in this Set
- Front
- Back
what are the 5 basic tissue types? |
1. blood 2. muscle 3. neuronal 4. epithelial 5. connective |
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what are the layers of the intestine? |
1. epithelium 2. connective tissue 3. circular fibers 4. longitudinal fivers (smooth muscle) 5. connective tissue (smooth muscle) 6. epithelium |
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what are the junction types? |
1. tight junctions 2. adhesion belts 3. gap junctions 4. desmosomes |
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tight junctions make _________ and divide______ |
cell sheet impermeable plasma membrane into two functionally different domains |
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adhesion belts do what? |
1. link actin cytoskeletons 2. provide strength to cell sheet |
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what do desmosomes do? |
1. link intermediate filament cytoskeletons 2. provide strength to cell sheet |
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what do gap junctions do? |
provide coupling between cells 1. electric coupling: heart, brain, muscle cells 2. chemical coupling: fish pigment cells, pancreas cells |
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adhesion belt connects with _______ |
cadherons (calcium sensitive) |
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in adhesion belts, the connection is the following: |
actin filaments > anchor proteins > cadherin dimers > anchor proteins > actin filaments |
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in desmosomes, cadherin is attached to: |
cytoplasmic plaque made of attachment proteins |
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a connexon is made of ____________. 2 are required for ________. These junctions are made of ______ |
6 channel subunits gate opening between two cells connexin, a 30 kD protein |
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The size of gap junction is ________. This lets through ________. |
15A nucleotides, cAMP, amino acids, ions, sugars |
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what is the real purpose of gap junctions? |
cell signaling! electric and chemical coordination |
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why would you regulate GAP junctions to close? how is it regulated? |
it is regulated by influx of CA++ ions (such as when a cell dies), this is because ions would diffuse into other cells through junctions, causing the plasma membrane to put out signal to be eaten by macrophage :( |
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why shouldn't cells be in perfectly aligned, tight contact? |
Wouldn't be able to get nutrients and O2! |
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The cells in the ECM include _______ which ______ and ______ which ______. |
1. fibroblasts > secrete ECM components 2. lymphocytes like macrophages, etc. |
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what are the functions of ECM? |
1. space for nutrients/o2/growth factors/cell migration 2. strength/flexibility/resistance to compression for tissue 3. template for cell regeneration 4. marker for tissue location |
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_______ provides strength in ECM. Made of ______, provides ____ percent of cell strength. The pattern is regulated by _____ |
collagen fibrils 25 secreting cell |
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in skin, fibril assembly is ______. in tendons, it is ______. In cornea, it is _______. In bone, it is ____ |
skin: grows in all directions tendons: strength one way, weak another cornea: thick, non deformable, clear (in cataracts don't lay the right way (random), cloudy) bone: laid at right angles, then Ca++ added |
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_______ provides flexibility in ECM |
elastin! |
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elastin molecules are connected by ______ |
crosslinking |
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elastin allows for contraction in what? |
1. skin: bouncy and taut/retain shape 2. blood vessels expand/contract 3. lungs expand with air |
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what is wrong in emphysema that it affects air sacs? |
elastase chews up elastin, so air sacs don't contract well after inhalation/exhalation. |
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GAGs and proteoglycans help with ________ |
compression allow for diffusion take up space |
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GAGs and proteoglycans take up ______ percent of ECM by weight, but because of _______ takes up most of volume. this is because primarily made of ______. |
~10 % hydrated GAGs sugars! |
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how do cells stick to ECM? |
fibronectin! |
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how do cells use fibronectin? |
they have an integrin, a fibronectin receptor! |
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The integrin is attached to _________ in the cell, then attaches to _____ outside of the cell which is attached to _____. |
stress fiber fibronectin collagen |