Digestive System: Esophagus Flashcards
What is the function of the esophagus?
Transfer bolus to stomach from the oropharynx
What surface epithelium makes up the mucosa of the esophagus?
Stratified squamous
What is unique about the surface epithelium of the esophagus?
Contains Langerhans cells: APC with possible phagocytosis
What makes up the lamina propria of the esophgus?
Loose areolar CT
What kind of glands can the lamina propria of the esophagus have?
Esophageal cardiac glands
What is the function of the esophageal cardiac glands?
Produce neutral mucus to protect esophageal epithelium
What are the two regions where the esophageal cardiac glands located?
Often near the pharynx ~ 1 inch
Near the stomach ~last inch (first discovered here)
What is the muscularis mucosae of the esophagus?
Discontinuous layer of longitudinal muscle
Where is the muscularus mucosa of the esophagus thinner at? Thicker at?
Thinner distally (by pharynx) and thicker proximally (by stomach)
What is the submucosa of the esophagus made up of?
Dense fibroelastic CT
What kind of glands does the submucosa of the esophagus contain?
Esophageal glands (proper) that are scattered
What is the function of the esophageal glands?
Produce slightly acidic mucus to lubricate the movement of food
How does parasympathetic stimulation affect the gut?
Stimulates peristalsis, inhibits sphincters, activates secretion
How does sympathetic stimulation affect the gut?
Inhibits peristalsis, contracts sphincters, controls blood flow to the gut
Where does parasympathetic stimulation to the gut come from?
Vagus nerve EXCEPT the descending colon/rectum which comes from sacral nerves
Where does sympathetic stimulation to the gut come from?
Splanchnic nerves
What makes up the muscularis externa of the esophagus?
Normal pattern of inner circular and outer longitudinal layers
What kind of muscle makes up the upper 1/3 of the esophagus? Middle 1/3? Lower 1/3?
Upper 1/3- Skeletal muscle
Middle 1/3- Mixture of smooth and skeletal muscle
Lower 1/3- Smooth muscle
Does the esophagus contain mostly serosa or adventitia?
Contains mostly adventitia except the last 1/2 inches after the diaphragm (which is serosa)
How many physiological sphincters make does the esophagus have? What are their names?
Two; Pharyngoesophageal sphincter and Gastroesophageal sphincter (lower esophageal sphincter)
Where is the pharyngoesophageal sphincter located?
Between the oropharynx and esophagus
Where is the gastroesophageal sphincter located?
Between esophagus and stomach
Which esophageal sphincter is prone to problems from abrupt change?
Gastroesophageal sphincter
What 4 complimentary forces does the gastroesophageal/lower esophageal sphincter involve?
Diaphragm contraction
Greater intra-abdominal pressure than inta-gastric pressure being exerted upon the abdominal part of the esophagus
Peristalsis
Maintenance of correct anatomical arrangements of structures
What are the characteristics for physiological sphincters?
No thickening of circular muscle in muscularis externa
Pressure gradient aids movement (muscle contractions and gravity help)
