Digestive Test Flashcards
What organs are part of the alimentary canal?
The GI tract; mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus.
What are the mouth, pharynx, esophagus, stomach, small intestine, large intestine, and anus a part of?
The alimentary canal
What does the digestive system do?
It digests food and absorbs materials
What is mechanical digestion?
Chewing, mixing, churning, segmentation, etc
What is chewing, mixing, churning, and segmentation?
Mechanical digestion
What’s chemical digestion?
The breaking down of molecules with enzymes
What is the breaking down of molecules with enzymes?
Chemical digestion
What is the difference between mechanical and chemical digestion?
Mechanical is chewing and mixing, chemical is enzymes breaking stuff down
What is ingestion?
Taking in food
What is taking in food called?
Ingestion
What is propulsion?
Moving food through the digestive system
What is moving food through the digestive system called?
Propulsion
What is absorption?
When chemicals are absorbed across the wall of the lumen
What is it called when chemicals are absorbed across the wall of the lumen?
Absorption
What is defection?
The elimination of indigestible materials
What is the elimination of indigestible materials called?
Defection
What are the two main types of receptors in the GI tract?
Mechanoreceptors and chemoreceptors
What is the mesentery?
It’s a double layer of peritoneum extending from the body wall
What’s a double layer of peritoneum extending from the body wall?
The mesentery
What does the mesentery do?
It connects to organs in the body cavity and routes nerves/vessels/lymphatics
What connects to organs in the body cavity?
The mesentery
What routes nerves/vessels/lymphatics?
The mesentery
What is splanchnic circulation?
Arteries that serve digestive organs
What are arteries that serve digestive organs a part of?
Splanchnic circulation
What are the four tunics of the alimentary canal?
Mucosa, submucosa, muscularis externa, serosa
What are the Mucosa, submucosa, muscularis externa, & serosa a part of?
The tunics of the alimentary canal
What does the mucosa do?
It absorbs nutrients, protects against disease, and secretes mucus enzymes
What tunic absorbs nutrients, protects against disease, and secretes mucus enzymes?
The mucosa
What tunic is made up of simple columnar epithelial tissue?
Mucosa
What does the submucosa do?
It contains blood, nervous tissue, and lymph and it supplies blood to the GI wall
What contains blood, nervous tissue, and lymph and it supplies blood to the GI wall?
The submucosa
What does the muscularis do?
It controls sphincters, peristalsis, and segmentation
What controls sphincters, peristalsis, and segmentation?
The muscularis
What is the serosa?
The outer alimentary tunic
What tunic is made up of connective loose tissue and some elastic?
The submucosa
What is the submucosa made up of?
Loose connective tissue and some elastic
What is the muscularis made up of?
Circular on the inner layer and longitudinal on the outer layer
What tunic is made up of a circular inner layer and a longitudinal outer layer?
The muscularis
What tunic is made up of visceral peritoneum and loose areolar with a simple squamous surface?
The serosa
What makes up the serosa?
Visceral peritoneum and loose areolar with a simple squamous surface
What is the enteric nervous system?
A semiautomatic part of the nervous system that’s controlled by the sympathetic and parasympathetic
What is controlled by both the sympathetic and parasympathetic?
The enteric nervous system
What regulates activity of glands and smooth muscle in the mucosa?
The enteric nervous system
What does the enteric nervous system do?
It regulates activity of glands and smooth muscle in the muscosa
What does saliva do?
It dissolves food chemicals for tasting, moistens food to compact into balls, and contains chemical digestion enzymes
How long is the esophagus?
25 cm
What’s a special feature of the esophagus?
It’s collapsed when inactive
Where does the esophagus end?
When it joins the stomach at the cardiac oriface/cardiac sphincter
How big is the stomach?
It’s 6-10 inches long and 50 ml when empty + 2 L when full
What is a part of the stomach?
Rugae
What are the three regions of the stomach?
Cardiac, fundus, and pyloric
What are cardiac, fundus, and pyloric names for?
They’re the three regions of the stomach
What does the stomach do?
It continues the work of the oral cavity by digesting food with enzymes and delivering chyme to the small intestine
What delivers chyme to the small intestine?
The stomach
How doesn’t the stomach digest itself?
The mucosal barrier
What are the three phases of gastric secretion?
Cephalic, gastric, and intestinal
What do cephalic, gastric, and intestinal mean?
They’re the three phases of gastric secretion
Describe the cephalic phase
It’s a conditioned reflex that’s triggered by thought and smell that happens before the food even enters the stomach
Whats an example of a conditioned reflex?
The cephalic phase
Describe the gastric phase
It takes 3-4 hours and involves digestive juices
Which phase is especially involved with digestive juices?
The gastric phase
What happens during the intestinal phase?
A surge followed by “gastric breaks”
How big is the small intestine?
2-4 meters long, 2.5-4 centimeters in diameter
What is responsible for virtually all absorption?
The small intestine
What are the three parts of the small intestine?
Duodenum, jejenum, and ilium
What happens in the duodenum?
Accessory organs give their contents to the duodenum
What holds all the parts of the small intestine in place?
The mesentery
Where are circular folds, villi, and microvilli more prominent?
In the proximal portion where absorption is greatest
What do circular folds, villi, and microvilli do for the small intestine?
They increase surface area by 600 times
Where are circular folds, villi, and microvilli located?
In the small intestine
Where are goblet cells and peyers patches more prominent?
In the distal portion of the small intestine
What does the liver do?
It produces bile
What does bile do?
It emulsifies fat
What produces bile?
The liver
What are the parts of the hepatic triad?
Hepatic artery branch, hepatic portal, vein branch, and bile duct
What do acinar cells do?
They make 1200-1500 milliliters of pancreatic juice a day
What makes pancreatic juice?
Acinar cells
Which alimentary juice is slightly basic?
Pancreatic juice
What is in pancreatic juice?
Water, enzymes, and electrolytes
What part activates pancreatic juice?
The duodenum
What does the pancreas do?
It makes pancreatic juice
How big is the large intestine?
It’s 1.5 meters long and 7 centimeters in diameter
What does the large intestine do?
It absorbs remaining water
What are teniae coli?
3 bands of longitudinal muscle in the large intestine
What are the 3 bands of longitudinal muscle in the large intestine called?
Teniae coli
What are the haustra?
Pocket-like sacs in the large intestine
What are the pocket-like sacs in the large intestine called?
Haustra
What are epiploitic appendages?
Fatty visceral peritoneum hanging on the surface of the large intestine
What are the features of the large intestine?
Teniae coli, haustra, epipiolic appendages, bacterial flora
How many types of bacterial flora are there?
10 million
What do bacterial flora do?
They metabolize host molecules, ferment indigestible carbs, synthesize B complex and vitamin K, and help the immune system
What metabolizes host molecules and ferment indigestible carbs?
The bacterial flora
What are the byproducts of bacterial flora?
Acid and up to 500 ml of gas a day
What synthesizes B complex and vitamin K?
Bacterial flora
What do bacterial flora synthesize?
B complex and vitamin K
What part of the alimentary canal helps the immune system?
Bacterial flora in the large intestine
