Term
|
Definition
| fibroblasts, wbc, macrophages, sperm |
|
|
Term
| When are cells most motile in humans |
|
Definition
| during embryonic development--> gastrulation |
|
|
Term
|
Definition
1) Swimming through fluid-- use of cilia or flagella (only Sperm)
NOTE: only sperm use flagella for locomotion
2)Crawling- requires substratum ie actin rearrangement |
|
|
Term
| What is role of Motility in cancer ? |
|
Definition
| tunor can in vade neighboring tissue and crawl into blood or lymp vessels--Spread |
|
|
Term
| Role of motility in lymphatics |
|
Definition
| macrophage and neutrolis can move to site of infection to engulf foreign substance |
|
|
Term
| Role of motility in wounds |
|
Definition
| fibroblast/platelets- move through CT for remodeling and repair |
|
|
Term
| Role of motility in Development |
|
Definition
|
|
Term
|
Definition
| -a horizontal layer of any material. |
|
|
Term
| Purpose of cilia on immotile cells |
|
Definition
1) create a current in fluid
2) move particles down throat
3) drive egg and conceptus down fallopian tube |
|
|
Term
Focal adhesion
b) VELCRO EFFECt |
|
Definition
Cluster of integrin proteins (aka focal contact) attached to actin and underlying substratum/ecm. (actin->integrin->ecm)combination.
B) integrins dont have high affinity for ligand, reqs lots of focal adhesions for effective attachment=where 100's of ks of focal adhesions make a large effect. |
|
|
Term
|
Definition
transmembrane heterodimers
bind actin intracellularly and a ecm components extracelularly
diff combination of subunits leads to diff ligand binding properties (diff tracks)-->gives specificity to where cell should crawl |
|
|
Term
|
Definition
extracellular domain: contain and alpha and beta subunit-> in btwn them is a ligand binding site. type of alpha (24 types) and beta (9 types) subunit determines what kind of ligand can bind
Intracellular domain: binds cytoskelton or actin network |
|
|
Term
types of cell-matix adhesion
and their components |
|
Definition
1)Hemidesome- integrin attaches to IF inside cell (MAINLY IMMOTILE/permanent CELLS)
2) Focal Adehison- attach actin to integrin for motile cells |
|
|
Term
|
Definition
integrin with bound ecm component ie fibronectin between two extracellular subunits
|
|
|
Term
|
Definition
ie: tallin, vinculin, paxillin, tensin
attach integrin (intrcallularly) to actin |
|
|
Term
|
Definition
| bind actin binding proteins, which only bind when integrin is activated. send survival signal to cell basically telling cell that integrin is activated ie bound to ecm |
|
|
Term
anchorage dependence and B) why is this important?
C) do cancer cell have this mechanism? |
|
Definition
if cell does not remain atached via integrin it will undergo apoptosis.
b) imporant mechanism to ensure correct cell are
growin in right place.
c) no |
|
|
Term
| How does cell regulate motility |
|
Definition
activation of integrin: opening up of extracellular binding sites.
which will lead to strong talin binding intracellularly |
|
|
Term
| types of cell cell adhesion and main components |
|
Definition
what are
1) tight junction- contain claudins
2) adhesion belt- contain cadherins
3) desomosomes cadherins to IF
4) gap junctions |
|
|
Term
|
Definition
cell senses soluble molecules down their conc gradient to their source
can be away from but usually TOWARD |
|
|
Term
|
Definition
1) polymerization of actin at leading edge, contraction of myosin and actin at back
2) activation of integrin at leading edge in activation of integrin at trailing edge |
|
|
Term
| what determines where a cell will crawl? |
|
Definition
1) insoluble molecules in substratum
2) chemotaxis |
|
|
Term
| who/what secretes ecm molecules to which integrin will attach to |
|
Definition
| the cell it self so that a migrating cell will use these ecm components as a track. |
|
|
Term
| what determines which track cell will follow |
|
Definition
| the types of integrin molecules expressed on cell surface |
|
|
Term
| how neutrophils catch their prey? |
|
Definition
| Neutrophils=first line of defense against bacterial infections. After leaving nearby blood vessels, these cells recognize chemicals produced by bacteria in a cut or scratch and migrate "toward the smell". The above neutrophils were placed in a gradient of fMLP (n formyl methionine- leucine- proline), a peptide chain produced by some bacteria. The cells charge out like a "posse" after the bad guys. |
|
|
Term
| similarity of bacteria and mitochondria? with regard to neurtophil signal |
|
Definition
| mitochondria also have fmet at begiing of their proteins= when a cell under goes necorsis, this is what attracts neutophils to area= 1 reason for inflamation |
|
|
Term
| chemotactic factors are respnonsible for the following? |
|
Definition
immune response
inflamation
wound healing
general systemic reactions |
|
|
Term
| most important chemotactically active factor |
|
Definition
cytokines
also involved:
c5a= part of complement cascade
n-formylated oligopeptides
intermediates of lipid metabolism: arachidonic acid and leukotriene b4 (LTB4) |
|
|
Term
|
Definition
1) regulate immunity, inflamation and hematopoiesis
2) by binding cell surface receptors they initiaition 2nd messenger signalling often via tyrosine kinase
3) binding of cytokine can increase or decrease expression of particular cell surface recep |
|
|
Term
| what is most imporant cytokine? |
|
Definition
chemokine- has chemotactic activity specificlaly for wbc
other not as important include:
lymphokine
monokine
interluekin- cytokine which is made by leukocyte and acts on another leukocyte |
|
|
Term
| how do chemotactic factors work? |
|
Definition
factors like fmlp bind receptors on cell-->activates 2nd messenger pathway--> integrin activation and actin polymerization
inc. Ca2+ gradient inside cell |
|
|
Term
| order of how fast a particular cell can travel? |
|
Definition
| sperm>WBC>fibroblast=nerve cell |
|
|
