T/F The organization of tissues provides mechanical integrity to otherwise squishy cells
True. They provide integrity
T/F Tissue organization allows cells to communicate with one another and to perform specialized functions in a coordinated way
True. The organization allows that
T/F Tissues don't require cells to recognize and bind to one another in the ECM
False! They require cells
What are the 2 architectural extremes of tissues in animal cells?
Epithelial tissues and connective tissues
What is the difference between Epithelial and connective tissues?
Epithelial tissues are like the outer flat covering that is your skin. Connective tissues is all the tissues underneath connecting to your bones and etc.
What are the 4 types of cell junctions?
- Anchoring junctions
- Occluding junctions
- Channel forming junctions
- signal relaying junctions
What do anchoring junctions do?
They "anchor" make sure the cells stick together
What does occluding junctions do?
They act as like a plug or seal to prevent leaking
What does channel forming junctions do?
They force squished cells apart. Like the car thing that pushes the car off the ground. Makes space basically
What does signal relaying junctions do?
Neuronal synapses
What does CAMs stand for?
Cell Adhesion Molecules
What are the 4 CAM families?
- Cadherins (cell-cell)
- Integrins (cell-matrix)
- Selectins (cell-cell in bloodstream)
- Immunoglobins (Ig)
Which CAM families have homophilic interactions?
Cadherins and Immunoglobins
Which CAM families have heterophilic interactions?
Integrins and Selectins
T/F Binding of the extracellular ligand activates signal transduction, resulting in changes to gene expression
True. It leads to gene expression
T/F Ca2+ makes Cadherins stiffen up
True. They stiffen with Ca2+
What are the 2 main subtypes of Cadherins?
- E-cadherin (epithelial)
- N-cadherin (nerve/muscle)
T/F Cadherins are important in embryonic development
True.
- They hold together embryonic tissue
- They sort out embryonic cells
Cadherins are important in adults too. How?
- Epithelial cell junctions (holding together of skin)
- adhesion and synaptic junctions (brains?)
How is the neural tube formed from cadherins?
The ectoderm does something like a pinch from endocytosis and the "vesicles" are a variety of cadherins but mainly N cadherin focused
Tumor cells will reduce the ability of cancerous growth when ______ is expressed.
cadherins
What are desmosomes?
Rivets to intermediate filaments (keratin) joining lots of epithelial cells
Ig superfamily CAM
Important in immune and neuronal function.
Selectins bind using ________ and can be found on leukocytes, endothelial cells and platelets
sugar residues
How CAM reacts to an inflammatory response
Leukocytes flood the system and the selectins help them ingest the damaged or foreign cells which produces pain and swelling
What is an example of tight junctions in the body?
Later