Instead the plates slide horizontally past one another. No matter the type of boundary though, the movement of the Earth's tectonic plates is essential in the formation of the various landscape features we see across the globe today.
As the death rattle does not always respond to these interventions, Bennett conducted further research into this phenomenon and came up with the conclusion that there is more than one type of death rattle. Physiological Theory: Causes of Death Rattle. Bennett (1996) identified two different types of death rattle. Type I is caused by an accumulation of salivary secretions when swallowing reflexes are inhibited and type II is caused by an accumulation of bronchial secretions in patients too weak to cough effectively (Bennett, 1996).
Some researchers have attempted to differentiate between death rattle that does or does not respond to medication by noting an association between refractory symptoms and pathological respiratory processes such as lung metastases and infection.