Module 6 Flashcards
organism hierarchy
cells
tissue
organs
body systems
organisms
cell junctions
type of membrane protein facilitating cell to cell attachments
endothelial cells
cells that line the inside of blood vessels
protective barrier
epithelial cells
cells that line the cavities and surfaces of organs
rest on basement membrane (specialized extracellular matrix that separates them from connective tissue)
types of junction proteins
tight junctions
adherens junctions
desmosomes
all part of junctional complex
tight junctions
structurally and functionally dived the plasma membrane into two domains (apical surface - top, basal surface - bottom)
phospholipids cant move across tight junctions
proteins in tight junction connect to cell cytoskeleton
regulate paracellular transport
adherens junctions
use transmembrane receptor proteins (cadherins) that bind to other cadherins on neighbouring cells
overlap of cadherins is proportional to bond strength
found in neural synapses and cardiac muscles
desmosomes
provide structural integrity to cell
function like snaps to eachother
link cytoskeleton of cell
found in cells exposes to physical stress (skin and cardiac muscles)
gap junctions
built of two halves, connect to cross intercellular gap
cells connected by gap junctions use channel gating to move ions sugars nucleotides and other molecules
important in cardiac muscles contraction
extracellular matrix (ECM)
network of molecules that fill space between cells
proteins formed by cells to provide external structure and support of the cells and tissues of the body
without tissues cant hold together properly
basement membrane
special matrix below epithelial cells and on outside of tissues
consist of special sheet of collagen and other proteins that is a structure foundation and barrier for epithelial cells and a network to stabilize tissue
types of ECM proteins
collagen
fibronectin
elastin
laminins
proteoglycans
collagen
main structural protein of ECM
exists as triple helix which crosslink to form fibrils which form collagen fibers
multiple types specific to different tissues
fibronectin
glycoproteins that connect cells to collagen matrices, cell adhesion
expressed as dimers and bind to integrins
interactions with cytoskeleton cause dimers to straighten and associate with other fibronectins resulting in fibrils at the cell surface
elastin
give elasticity to tissues allowing them to return back to original shape after being distorted by external force
have hydrophobic and hydrophilic regions allowing them to return