Air must pass from the back to the front of the pharynx to enter the trachea and food must pass from the front to the back of the esophagus
The stamen is the part of the flower that produces pollen.
If a researcher electrically stimulates the reticular formation in an animal, the animal will immediately wake up and be alert. Its purpose is to have some control of sensory signals and thus has the ability to alert the body when it is tired or needs to be awake.
The lining attached to the lungs is called the visceral pleurae.
