What are the two main components of the digestive system? - Answers The gastrointestinal (GI)
tract (alimentary canal) and accessory digestive organs.
What is the function of the gastrointestinal (GI) tract? - Answers Transport, digestion, and
absorption of food.
List the seven divisions of the GI tract. - Answers Oral cavity, pharynx, esophagus, stomach,
small intestine, large intestine, and anus.
What are accessory digestive organs? - Answers Structures that assist digestive organs but do
not directly interact with food, including teeth, tongue, salivary glands, liver, gallbladder, and
pancreas.
What is mechanical digestion? - Answers The physical breakdown of food into smaller pieces.
What is chemical digestion? - Answers The breakdown of food molecules by enzymes, resulting
in new kinds of molecules.
What is the role of enzymes in digestion? - Answers Enzymes facilitate the chemical digestion
of food by breaking chemical bonds.
What are the main enzymes involved in carbohydrate digestion? - Answers Salivary amylase,
pancreatic amylase, maltase, sucrase, and lactase.
What enzyme is responsible for protein digestion in the stomach? - Answers Pepsin.
What are the steps of the digestive process? - Answers Ingestion, secretion, digestion, motility,
absorption, and egestion (defecation).
What is the function of the mucosa in the digestive tract? - Answers It lines the GI tract and
contains epithelial cells that secrete substances and absorb nutrients.
What are the four tissue layers of the GI tract? - Answers Mucosa, submucosa, muscularis
externa, and serosa (or adventitia).
What is the role of the submucosal plexus? - Answers It regulates gastrointestinal secretions.
What is the role of the myenteric plexus? - Answers It regulates gastrointestinal motility.
What types of cells are found in the mucosa? - Answers Exocrine cells (secreting mucus,
enzymes, acids), endocrine cells (hormones), and absorptive cells (enterocytes).
What are Peyer's patches? - Answers Immune nodules found in the small intestine.
How does diet affect digestion and health? - Answers Diet influences the efficiency of digestion,
nutrient absorption, and overall health.
,What are the four main types of secreting cells in gastric glands? - Answers Parietal cells (HCl),
chief cells (pepsinogen), mucous cells (mucus), and enteroendocrine cells (hormones).
What is the significance of enamel in teeth? - Answers Enamel protects the tooth and is the
hardest substance in the body.
What is the function of the salivary glands? - Answers They secrete saliva, which contains
enzymes that begin the digestion of carbohydrates.
What is the role of the liver in digestion? - Answers The liver produces bile, which aids in the
digestion and absorption of fats.
What is the function of the gallbladder? - Answers It stores and concentrates bile produced by
the liver.
What is the function of the pancreas in digestion? - Answers The pancreas produces digestive
enzymes and bicarbonate to neutralize stomach acid in the small intestine.
What is the role of bacterial flora in the digestive system? - Answers They aid in digestion,
produce vitamins, and protect against harmful bacteria.
What is the difference between motility and secretion in digestion? - Answers Motility refers to
the movement of food through the GI tract, while secretion refers to the release of digestive
juices and enzymes.
What is the submucosa in the GI tract? - Answers The submucosa is the connective tissue layer
underneath the mucosa that contains blood vessels, lymphatic vessels, and nerves.
What are the two plexuses found in the submucosa? - Answers The submucosal plexus and the
myenteric plexus.
What is the function of the submucosal plexus? - Answers It alters exocrine and endocrine
secretions and changes the lumen shape via the underlying muscularis mucosae.
How does the enteric nervous system interact with the CNS and ANS? - Answers While the
plexuses function independently, sensory information from the GI tract is sent to the CNS and
ANS, which can alter plexus activity.
What is unique about the muscularis externa of the stomach? - Answers The stomach has three
layers of muscularis externa: oblique, circular, and longitudinal.
What is peristalsis? - Answers Peristalsis is the successive contractions of muscle that propel
food forward through the GI tract.
What is segmentation in the GI tract? - Answers Segmentation involves alternating muscle
contractions that isolate and mix food particles.
, What are mass movements in the colon? - Answers Mass movements are powerful peristaltic
contractions of the colon that facilitate egestion.
What is the serosa in the GI tract? - Answers The serosa is the outermost connective tissue
layer that extends to form the peritoneum and mesenteries.
What is the function of the lesser omentum? - Answers The lesser omentum connects the
lesser curvature of the stomach to the liver.
What is the purpose of the greater omentum? - Answers The greater omentum drapes over the
small intestines and connects to the transverse colon.
What is the goal of the cephalic phase of digestion? - Answers The goal is to prepare the mouth
and stomach for ingestion, stimulating salivation and gastric juice secretion.
What occurs during the gastric phase of digestion? - Answers The gastric phase encourages
mechanical and chemical digestion in the stomach through enteric nerves and the
parasympathetic nervous system.
What is the focus of the intestinal phase of digestion? - Answers The intestinal phase aims to
increase intestinal digestion while decreasing stomach digestion, initiated by the enterogastric
reflex.
What initiates the cephalic phase of digestion? - Answers The sight, smell, taste, or thought of
food.
Which structures are involved in detecting stimuli during the cephalic phase? - Answers
Cerebrum, hypothalamus, and medulla oblongata.
What nerves are responsible for increasing salivation during the cephalic phase? - Answers
Facial nerve (cranial nerve #7), glossopharyngeal nerve (#9), and vagus nerve (#10).
What is the primary function of the mouth in digestion? - Answers Lubrication, mechanical and
chemical digestion, manipulating food, and analyzing items before swallowing.
What is mastication? - Answers The process of chewing, primarily done by the teeth.
What is a bolus? - Answers A soft, flexible mass of food that can enter the esophagus.
What type of epithelium lines the mouth for protection? - Answers Stratified squamous
epithelium.
What are the three types of salivary glands and their saliva contributions? - Answers Parotid
glands (20-50%), submandibular glands (10%), and sublingual glands (7-8%).
What is the composition of saliva? - Answers 99.5% water and 0.5% solutes including ions,
mucus, lysozyme, IgA/IgE, and digestive enzymes.