Pulmonary surfactant<span> is a mixture of lipids and proteins which is secreted into the alveolar space by epithelial type II cells. The main </span>function<span> of </span>surfactant <span>is to lower the surface tension at the air/liquid interface within the alveoli of the </span>lung<span>.
Source: </span>http://www.sciencedirect.com/science/article/pii/S000527360000256X
oral phase
: During the oral phase, food is chewed and mixed with saliva to form a soft consistency called a bolus.
pharyngeal phase
: During the pharyngeal phase, the vocal folds close to keep food and liquids from entering the airway.
esophageal phase: As food leaves the pharynx, it enters the esophagus, a tube-like muscular structure that leads food into the stomach due to its powerful coordinated muscular contractions
Explanation:
Answer:
Proper educational background Licensing test Letter of recommendation Application
Let's pick your role as a son/daughter, friend, and pupil.
When you're at home with your parents and talk to them, do chores, eat breakfast together, etc. you're playing the role of a son or daughter.
When you're hanging out with your friends, doing random stuf, having a good time, your're assuming your role as a friend.
When you're at school, studying, attending a lecture and listening to your teacher, you're assuming your role as a pupil.