Inhalation occurs when the: a. diaphragm and intercostal muscles contract and cause a decrease in intrathoracic pressure. b. diaphragm and intercostal muscles relax and cause an increase in intrathoracic pressure. c. diaphragm and intercostal muscles ascend and cause an increase in intrathoracic pressure.

hey there!

so, when you eat, your teeth chew and grind food into smaller pieces. this is mechanical digestion. then reactions aided by digestive enzymes break down large food molecules into smaller molecules. this is chemical digestion. the two processes change the food into simpler substances that can be used by the body for raw materials and energy.

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tobey