A sneak peek into the reason behind peristalsis...

There are two types of muscles in the esophagus.

During peristalsis, one of the muscles will contract and the other will relax.

• ·      Circular muscles (vertical muscles)
• ·      Smooth muscles (horizontal muscles)

    

    When the circular muscles contract, it becomes shorter.

    

    When the smooth muscles contract, they make the opening of the esophagus smaller. (smaller diameter of the esophagus). 

Introduction to diffusion

Based on a video that we watched in class...

Is diffusion a spontaneous process? (no energy required)

Yes, energy is not required for diffusion to take place.

Why does diffusion not occur instantaneously in the living world?

Diffusion occurs instantaneously in vacuum. However, there is barely any places with vacuum in the living world, except in experimental set-ups.


What are the factors affecting rate of diffusion?

• The size of the particles
• The temperature of the fluid in which the particles are in