Exam 3 – Dr. Mackin Physiology of Pharynx/Esophagus Flashcards
What is swallowing?
Process by which food and water are transported from the mouth to the stomach
What are the anatomic phases of swallowing?
Oral phase
Esophageal phase
Gastroesophageal phase
What is the oral phase?
When food comes from the bowl and goes to the esophagus
What are the stages of the oral phase?
Oral stage
Pharyngeal stage
Cricopharyngeal stage
What is the oral stage?
Something you are aware of
Composed of the tongue, lips, and jaw
What is the pharynx?
Where the trachea and esophagus meet
What is the cricopharyngeal sphincter?
The gate keeper at the top of the esophagus
What are the stages of the esophageal phase?
Primary peristalsis
Secondary peristalsis
What is primary peristalsis triggered by?
Swallowing from the pharynx
What is secondary peristalsis triggered by?
Sensing materials in the esophagus
What is a part of the gastroesophageal phase?
Lower esophageal sphincter
What does the lower esophageal sphincter do?
Creates a seal that stops gastric contents from going back into the the esophagus and lets things go into the stomach
What makes up the pharynx?
Nasopharynx
Oropharynx
Laryngopharynx
What are the nasopharynx and oropharynx divided by?
Soft palate
What are the functional phases of swallowing?
Preparatory phase
Transfer phase
Transport phase
What is a part of the preparatory phase?
Oral cavity
What is part of the transfer phase?
Oral cavity and pharynx
How quickly does something move through the transfer phase with the oral cavity and pharynx?
40 cm/sec
What is part of the transport phase?
Esophagus
How quickly does something move through the transport phase with the esophagus?
3-4 cm/sec
Which of the functional phases swallowing is voluntary?
Preparatory phase
What are the transfer and transport phases looked after by?
Nervous system
What nerve innervates the muscles of mastication?
Trigeminal nerve (5)
What nerve innervates the muscles of facial expression?
Facial nerve (7)
What nerve innervates the muscles of the tongue?
Hypoglossal nerve (12)
What nerves innervate the muscles of the pharynx?
Cranial nerves 9, 10, and 11
What nerve is the key player in voluntary swallowing?
Vagus nerve (10)
What nerve innervates the larynx?
Recurrent laryngeal nerve, a branch of the vagus (10)
What does the vagus nerve supply?
Pharynx Larynx Cricopharyngeal sphincter Esophagus Lower esophageal sphincter
What are all the nerves that are involved in swallowing?
Trigeminal (5) Facial (7) Glossopharyngeal (9) Vagus (10) Accessory (11) Hypoglossal (12)
Describe the upper esophageal sphincter of the esophagus
Cricopharyngeal muscle Striated muscle Skeletal muscle Wraps around larynx Supplied by vagus nerve
Describe the lower esophageal nerve
Not a true sphincter in dogs and cats
Considered a physiological sphincter
What is the esophagus like in a canine?
Striated and skeletal muscle along the entire length
Because the dog’s esophagus is skeletal, what kind of problem does that allow for?
Neuromuscular diseases can occur
What is the esophagus like in a feline?
Proximal 2/3 striated muscle
Distal 1/3 smooth muscle
Because the cat’s esophagus includes a smooth muscle portion that has autonomic system control, what kind of problem does that allow for?
Diseases that affect the autonomic system will effect the esophagus
What are the most important muscles of the esophagus?
Circular muscle
Longitudinal Muscle
Which is more tough, circular muscle or longitudinal muscle?
Circular muscle
