What does polarity mean in epithelial tissue?
ABSTRACT. Cell polarity is characterised by differences in structure, composition and function between at least two poles of a cell. In epithelial cells, these spatial differences allow for the formation of defined apical and basal membranes.
What does the basolateral membrane do?
The term basolateral refers to the membrane on the base and sides of the cell. The basolateral membrane forms a barrier between the cell and the blood and/or other cells. The basolateral membrane’s main function is to transport nutrients from the cell to the blood plasma through specialised protein transporters.
Where is the basolateral membrane?
Cellular component – Basolateral cell membrane The basolateral cell membrane is the fraction of the plasma membrane at the basolateral side of the cell, which faces adjacent cells and the underlying connective tissue.
Is the apical surface sometimes covered with cilia?
The apical surface will sometimes have specializations such as cilia or microvilli that assist with the function of the tissue.
Where are apical cells?
Apical cells are found primarily within the epithelium of the initial segment and intermediate zone,148–150 although they have been seen occasionally in other segments in aging rats. These cells have a characteristic apically located ovoid nucleus and do not contact the basement membrane (Figure 17.5).
How do epithelial cells show polarity?
Epithelial cell polarity is characterized by cells with apical and basolateral membrane domains separated by adherens and tight junctions. Loss of epithelial cell polarity is associated with cell plasticity, or the ability to differentiate into another cell type.
What is lateral or basolateral membrane?
Overview. The basolateral membrane of a polarized cell is the part of the plasma membrane that forms its basal and lateral surfaces, distinct from the apical (or lumenal) surface. This is particularly evident in epithelial cells, but also describes other polarized cells, such as neurons.
