Checkpoint Chapter 23
Give the name and function of each of the four layers if the GI tract. A. mucosa; inner surface for the secretion of digestive end products. B. submucosa: site of glands, blood vessels, lymph vessels and nerve plexuses. C. muscularis: circular and longitudinal muscles for propulsion and mixing. D. serosa: serous membrane to reduce friction with movement. 2.
Where along the GI tract is the muscularis composed of skeletal tissue? Is control of this skeletal muscle, voluntary? A. mouth, pharynx, super4ior and middle parts if the esophagus and external anal sphincter. B. voluntary. 3.
What are the attachment sites of the mesentery, mesocolon, falciform ligament, lesser omentum, and greater omentum? Mesentery – binds large intestine to posterior abdominal wall; falciform ligament – attaches liver to anterior abdominal wall and diaphragm; lesser omentum – suspends stomach and duodenum from the liver; greater omentum – from stomach and colon to transverse colon. 4.
What are the functions of the myenteric and submucosal plexuses? A. myenteric plexus: innervates smooth muscle of muscularis. B. submucosal plexus: enervates secretory cells of mucosal epithelium to control the secretions of the organs of the GI tract. 5.
Which structures form the mouth? Cheeks, hard and soft palate, tongue 6.
What is the name of the cone shaped process that hangs down from the roof of the mouth? What is its function? Superior birder: a. uvula b. closes off nasopharynx during swallowing. 7.
How are the major salivary glands distinguished on the basis of location? Parotid glands: located inferior and anterior to the ears, between the skin and masseter muscle; submandibular glands: located beneath the base of the tongue in the posterior part of the floor of the mouth; sublingual glands: superior to submandibular glands. 8.
How is the secretion of saliva regulated? A. Via ANS: parasympathetic fibers increase salivation; sympathetic fibers decrease salivation. B. Feel and taste of food: smell, sight, sound, or thought of food. 9.
Which functions to incisors, cuspids, premolars and molars perform? Incisors: grasping and tearing of food, cuspids: Tear and shredding of food; premolars: crushing and grinding; molars: crush and grind food in preparation for swallowing. 10.
Define mastication using the term bolus. Chewing food until it is formed into a soft ball called a bolus for swallowing. 11.
To which two organ systems does the pharynx belong? Respiratory and digestive 12.
What does deglutition mean? Swallowing
What are the functions of the upper and lower esophageal sphincters? Upper esophageal sphincters: regulates movement of food from the pharynx into the esophagus; lower esophageal sphincters: regulates movement of food from the esophagus to the stomach. 14.
What occurs during the oral, pharyngeal, and esophageal stages of swallowing? A. oral: voluntary passages of bolus into the oropharynx; b. pharyngeal: involuntary passage of bolus into the esophagus; c. esophageal: involuntary passage of bolus through the esophagus into the stomach. 15.
Is swallowing voluntary or involuntary? Both; oral phase is voluntary, pharyngeal and esophageal phases are involuntary. 16.
Does peristalsis “push” or “pull” food along the GI tract? Push 17.
Which stomach layer is in contact with swallowed food? Mucosa 18.
Which part of the stomach primarily serves as a food reservoir? Fundus 19.
Which molecule is the source of the hydrogen ions that are secreted into gastric juice? Carbonic acid. 20.
Which branch of the autonomic nervous system promotes digestion? Parasympathetic division. 21.
What is the role of pepsin? Why is it secreted in an inactive form? A. break peptide bonds between amino acids. B. in the inactive form, form pepsinogen, it cannot digest the proteins in the chief cells that produce it. 22.
Which substances are absorbed in the stomach? Water, ions, short-chain fatty acids, certain drugs. 23.
What are the structures through...
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