Question

describe an example where polarity plays a role in a specific physiological function

Answer 1

Cell polarity refers to the intrinsic asymmetry observed in cells, either in their shape, structure, or organization of cellular components, all cells exhibit some form of polarity, which enables them to carry out specalized function. Cell polarity is the asymmetric organisation of several cellular components, including its plasma membrane, cytoskeleton or organelles. This asymmetry can be used for specialised functions, such as maintaining a barrier within an epithelium or transmitting signals in neuron

Epithelial cells are one example of a polarized cell type, Epithelial cell polarity is characterized by cells with apical and basolateral membrane domains separated by adherens and tight junction,The membrane facing the lumen or free surface is known as the apical membrane, while the membrane oriented away from the lumen, contacting the extracellular matrix, is known as the basal membrane.Given that many tissues are lined by epithelia with apical cell membranes facing the lumen, polarization allows epithelial cells to transport molecules across the surface in a directional manner. Loss of epithelial cell polarity is associated with cell plasticity, or the ability to differentiate into another cell type.

Neurons  A typical neuron has a highly distinctive shape and structure, with one end adapted to receive signals through highly branched dendrites. This signal is then transmitted down an axon, which can stretch the length of the body. At the other end of the cell is the axon terminal, where the synapses are located. These synapses can release chemical neurotransmitters in order to propagate the signal or effect an action such as muscle contraction, so it is the polarity of the neuron thus facilitates the directional flow of information, which is required for communication between neurons and effector cells