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Example Question #1 : Help With Upper Respiratory Physiology
Both food and air pass through all except which of the following sections of the pharynx?
All pharynx sections allow passage of both food and air
The pharynx is located posterior to the nose and mouth and receives both inhaled air and masticated food before they are transferred to the trachea and esophagus, respectively. The pharynx is divided into three sections: the nasopharynx, oropharynx, and laryngopharynx. Food and air first enter the nasopharynx and proceed to the oropharynx. The laryngopharynx is the last portion of the pharynx, and is superior to the larynx, which is the passageway for air. Food is not meant to pass through the laryngopharynx and will result in coughing if it does.
Example Question #111 : Circulatory And Respiratory Physiology
Which structure is shared by the respiratory and digestive systems?
The pharynx is shared by the respiratory and digestive systems, and is separated into three sections. The nasopharynx is primarily used for respiration, while the laryngopharynx is primarily used for digestion; it is inferior to the epiglottis and connects to the esophagus. The oropharynx is shared by pathways for both respiration and digestion.
The trachea and alveoli are exclusively used for respiration, while the esophagus and pyloric sphincter are exclusively used for digestion. Alveoli are the site of gas exchange in the lungs. The pyloric sphincter connects the stomach to the small intestine.
Example Question #112 : Circulatory And Respiratory Physiology
If the volume of the lung increases, what happens to the air pressure inside the lungs?
It remains constant
It increases to a point, then decreases
It decreases to a point, then increases
If the volume of the lungs increases, the air pressure inside the lungs decreases. Boyle's Law can be used to describe the process of human breathing. It states that for fixed mass, pressure and volume are inversely proportional.
If the volume increases, then pressure must decrease in order for these equations to hold true. This is responsible for the mechanics of inspiration. As the diaphragm contracts, the volume of the lungs increases and creates a negative pressure differential with the environmental atmosphere. This pressure differential draws air into the lungs through the nose and mouth.