Hours per Day. You can generally expect to spend, at minimum, as much time studying as you spend in class. But most students will spend even more time studying. The University of Michigan-Flint recommends that students spend two to three hours studying for every course hour in which they are enrolled. So if you are taking 15 hours of courses per week, you can expect to spend 30 to 45 hours per week studying, or about six to nine hours each weekday. Your reading speed is a major factor in predicting how long you'll spend studying each day.
The esophagus is the tube that carries food, liquids and saliva from your mouth to the stomach. You may not be aware of your esophagus until you swallow something too large, too hot or too cold. You may also become aware of it when something is wrong.
Opening of the upper esophageal sphincter is triggered by the swallow reflex. The primary muscle of the upper esophageal sphincter is the cricopharyngeus portion of the inferior pharyngeal constrictor. The lower esophageal sphincter surrounds the lower part of the esophagus.