Mechanical forces are really important in how cells in our blood vessels work and can cause problems when things go wrong. Here's how they affect our body:

1. Shear Stress:

   • Endothelial cells (these are the cells that line our blood vessels) feel a force called shear stress because of blood flowing through the vessels.
   • This stress helps these cells make nitric oxide, which keeps our blood vessels relaxed and healthy.
   • But if there's too much shear stress for a long time, it can lead to a condition called atherogenesis, where fatty streaks build up in the blood vessels. Studies show that areas with low shear stress often end up with these buildups.

2. Stretch and Pressure:

   • Smooth muscle cells (these cells help our blood vessels squeeze and relax) respond to when blood vessels stretch or when there’s too much pressure, like in high blood pressure (hypertension).
   • When this happens, these muscle cells can grow bigger and even multiply.
   • In people with high blood pressure, the walls of their blood vessels can get thicker by as much as 40%.

3. Mechanical Strain:

   • The connections between cells, called intercellular junctions, can be affected by mechanical strain. This can trigger the body’s inflammation responses.
   • When there is mechanical strain, special proteins that cause inflammation can increase by 2-3 times. This can lead to changes in blood vessels and health problems.

In short, mechanical forces have a big impact on how healthy our blood vessels are. They can lead to problems like atherosclerosis and high blood pressure because of how our cells respond to changes in blood flow and pressure.