Topic 4. Cell Modifications

==Cell Modification== - are specialized or modifications re-acquired by cell after cell division that helps the cell in different beneficial ways.

==Apical Modification== - cell modification found on the apical surface of the cell.

Cilia and Flagella - formed from microtubules

@@Cilia@@ - are usually short, hair-like structures that move in waves

@@Flagella@@ - are long whiplike structures

Villi and Microvilli

@@Villi@@ - are finger-like projections that arise from the epithelial layer in some organs. They help to increase surface area allowing for faster and more efficient absorption.

@@Microvilli@@ - are smaller projections that arise from the cell’s surface that also increase surface area allowing faster and more efficient absorption

@@Pseudopods@@ - temporary, irregular lobes formed by amoebas and some other eukaryotic cells. Bulge outward to move the cell or engulf prey.

@@Extra Cellular Matrix (ECM)@@ - compound secreted by the cell on its apical surface. Cell wall is the extracellular structure in plant cells that distinguishes them from animal cells. Glycoprotein is the main ingredient of ECM in animal cells.

==Basal Modification== - cell modification found on the basal surface of the cell basement membrane

@@Desmosomes/Hemidesmosomes@@ - anchoring junction on the basal surface of the cell. Rivet-like links between cytoskeleton and extracellular matrix components such as the basal lamina that underlie epithelia. Primarily composed of keratin, integrins, and cadherins

==Lateral Modification== - cell modification found on the basal surface of the cell.

@@Tight Junction@@ - acts as barriers that regulate the movement of water and solutes between epithelial layers. Prevent leakage of ECF.

@@Adhering Junction@@ - anchoring junction on the lateral surface of the cell. Very similar to the anchoring junction of the basal surface of the cell. Fasten cells to one another

@@Gap Junction@@ - also known as communicating junctions. Closable channels that connect the cytoplasm of adjoining anima cells. Presence of connexon that allow direct exchange of chemical between the cytoplasm of two cells.