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Cell Biology > Cell Membranes > Problem
13: Cell junctions
Tutorial to help answer the question
The cell junctions respectively that exclude the passage
of water between cells, maintain tissue form and strength, and allow the
exchange of small molecules between cells are:
||gap junctions, desmosomes, and tight junctions.
||desmosomes, tight junctions and gap junctions.
||tight junctions, gap junctions, and tight junctions.
||gap junctions, tight junctions, and desmosomes.
||tight junctions, desmosomes, and gap junctions.
of junctions in animal cells
Tight junctions block the flow of fluids between epithelial cells.
For example, the cells that line the intestine are responsible
for taking up nutrients from the gut. The nature of the material
taken up must be controlled to block unwanted substances from
entering our bodies. The control comes from the fact that materials
must pass through receptors on the epithelial cell membranes.
Tight junctions form a water tight seal and prevent material
from passing between cells.
Desmosomes form links between cells, and provide a connection between
intermediate filaments of the cell cytoskeletons of adjacent cells.
This structure gives strength to tissues.
Finally, the need for signaling is a function of gap junctions
that form pores connecting adjacent cells. Small molecules and electrical
signals in one cell can pass through the gap junctions to adjacent
cells. This process allows tissues to coordinate responses to stimuli.
For example, gap junctions permit coordinated movements of muscles
leading to childbirth.
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