Flashcards in Upper GI Tract Structure and Function Deck (13):
How is chewing controlled?
Somatic nerves innervate skeletal muscles of mouth/jaw
What glands secrete saliva?
Parotid, submandibular, sublingual
What are the components of saliva?
What parasympathetic nerves control salivation?
Cranial nerves: facial (VII) and glossopharyngeal (IX)
How does parasympathetic stimulation effect salivation?
Profuse watery salivary secretions
How does sympathetic stimulation effect salivation?
High mucus content
High amylase content
What muscle type is involved in the oesophagus?
Upper 1/3 is skeletal muscle
Lower 2/3 is smooth muscle
Describe the swallowing process
Pharyngeal muscles contract
Soft palate reflected backwards and upwards (closes off nasopharynx)
Upper oesophageal sphincter (UOS) relaxes and epiglottis covers opening to larynx
How is bolus moved down the oesophagus?
What happens as the bolus nears the stomach?
Lower oesophageal sphincter (LOS) relaxes and bolus enters the stomach
What are the functions of the stomach?
Temporary store of ingested material
Controls delivery of contents to small intestine
Produces intrinsic factor
Sterilises ingested material
What are the 3 layers of the muscularis externa within the stomach?