A&P2 Chapter 26 - Digestive System
Which are tunics (layers) that make up the gastrointestinal wall? Check all that apply.
(Adventia)serosa muscularis mucosa submucosa
Two sets of teeth develop and erupt; the first set are 20 teeth called deciduous (milk) teeth and the final set are ____ teeth called permanent teeth.
32
Which phase(s) of gastric secretion is (are) regulated by the medulla oblongata?
All three phases are regulated by the medulla oblongata
Which of the following is not secreted by the stomach to aid in digestion?
Bile
A portal triad consists of which three structures?
Branches of a hepatic artery, hepatic portal vein, and bile ductule
What is the function of bile?
Break down fats to assist in their chemical digestion
As material moves through the large intestine, in what order does it pass through these structures?
Cecum Ascending colon Transverse colon Left colic flexure Descending colon Sigmoid flexure Rectum Anal canal
What are the three phases of gastric secretion?
Cephalic, gastric, and intestinal
Intestinal glands
Contain enteroendocrine cells
Bile from the liver and digestive juices from the pancreas enter which section of the small intestine?
Duodenum
Bolus passes from esophagus to stomach.
Esophageal phase
Peristalsis moves food bolus onward The lower esophageal sphincter relaxes
Esophageal phase
Carbohydrate digestion begins in the stomach.
False
Gastric secretion is increased in all three phases (cephalic, gastric, intestinal).
False
Mastication is the process of chemically reducing food bulk into smaller particles to facilitate swallowing.
False
Protein digestion begins in the small intestine.
False
The epithelial lining of the oral cavity has a transitional epithelium.
False
The esophagus extends from the nasopharynx to the stomach. The esophagus is about 25 meters long. The esophagus lies anterior to the trachea.
False
The liver lobule is the same as a hepatocyte.
False
The liver stores, concentrates, and releases bile into the duodenum.
False
The muscularis of the GI tract contains two layers of smooth muscles: the outer circular layer and the inner longitudinal layer.
False
When chyme enters the duodenum, gastric secretion increases.
False
When substances are moved through the epithelial cells that line the GI tract wall and are carried into the blood or lymph, this process is called secretion.
False
G-cells of the gastric glands in the stomach produce a hormone called __________ that stimulates stomach secretions and motility.
Gastrin
What are the primary hormones that participate in the regulation of the processes of digestion? Check all that apply.
Gastrin Cholecystokinin (CCK) Secretin
Parietal cells of the gastric glands in the stomach produce
HCl (hydrochloric acid)
What are the names of anatomic structures in the oral cavity? Check all that apply.
Hard plate Uvula
Normal bacterial flora in the large intestine are responsible for the production of vitamins B and
K
Which of the following is the correct order for the major parts of the gastrointestinal tract?
Mouth, esophagus, stomach, small intestine, large intestine
Check all that are a function of the esophagus.
Movement of a bolus of food from the pharynx to the stomach Prevents materials from returning from the stomach
Which of the following enzymes is produced by the stomach?
Pepsin
Select all that are major functions of the muscularis layer of the GI tract.
Peristalsis Mixing
Bolus passes from pharynx to esophagus.
Pharyngeal phase
Initiated by stimulation of tactile receptors in the oropharynx Begins with elevation of the soft palate The upper esophageal sphincter relaxes
Pharyngeal phase
Which of the following does not stimulate the secretion of HCl in the stomach?
Secretin
From external to internal, what is the correct order of layers of the stomach?
Serosa, muscularis, submucosa, mucosa
Circular folds
Slow passage of material
Secretin and cholecystokinin (CCK) are hormones that are secreted from what GI organ?
Small intestine
Check all that are characteristics of the esophagus.
The mucosa is composed of thick, nonkeratinized stratified squamous epithelium. The two layers of muscle in the superior one-third of the muscularis are skeletal
Which two fetal remnants are found on the liver?
The round ligament and the ligamentum venosum
Defecation reflexes are stimulated by the presence of feces in the rectum.
True
Gastrin functions to increase the production of HCl in the stomach.
True
Mass movements of the colon propel its contents toward the rectum.
True
Stimulation of the salivary glands is primarily through parasympathetic neurons from the facial (VII) cranial nerve to the submandibular and sublingual glands and from the glossopharyngeal (IX) cranial nerve to the parotid gland.
True
The duodenum is considered part of the upper gastrointestinal (GI) tract.
True
The muscularis of the esophagus is different from other parts of the digestive tract because the superior part of the esophagus consists of skeletal muscle. The esophagus contains both an upper and a lower esophageal sphincter that regulates the movement of materials into and out of the esophagus. The esophagus contains numerous mucous glands that produce a thick, lubricating mucus that coats the inner surface of the esophagus.
True
Chewing forms a bolus.
Voluntary phase
Food bolus forced into the oropharynx Food bolus pushed by tongue against the hard palate
Voluntary phase
The process of moving substances through the epithelial cells that line the GI tract into the blood or lymph is called
absorption
Salivary __________ breaks the chemical bond between two glucose molecules; it breaks down the long polysaccharide starch molecule into smaller and smaller pieces until only glucose results
amylase
Which region of the stomach is continuous with the esophagus?
cardiac region
Motility and secretion in the stomach is generated by the __________ reflex initiated by thought, smell, sight, or taste of food.
cephalic
Functions of the stomach include
chemical and mechanical digestion
Which cell of the gastric glands produces pepsinogen?
chief cells
The intestinal phase of digestion involves both the intestinal reflex and the release of two primary hormones: _______ and secretin.
cholecystokinin (CCK)
Which of the following are considered small intestine brush border enzymes participating in carbohydrate digestion?
dextrinase lactase sucrase
Receives bile and pancreatic juice
duodenum
Mass movements of the colon are integrated by
enteric plexus
Mass movements in the colon are stimulated by
food in the stomach and chyme in the duodenum
Structurally, the human liver is divided into how many lobes?
four
The greater omentum extends inferiorly like an apron from the _________ of the stomach and covers most of the abdominal organs.
greater curvature
Secretin is released from the duodenum in response to
hydrochloric acid in chyme
Controls entry of material into large intestine
ileum
Performs most chemical digestion and absorption
jejunum
The muscularis mucosae is a thin layer of smooth muscle immediately deep (external) to the
lamina propria of the mucosa.
The stomach is located in which abdominal quadrant?
left upper
Gastric secretion during the intestinal phase is inhibited by the presence of
lipids or low pH
What organ produces bile?
liver
Chewing requires the coordinated activities of teeth, skeletal muscles in lips, tongue, cheeks, and jaws that are controlled by nuclei within the medulla oblongata and pons, collectively called the ____________ center.
mastication
What are the names of the individual mesenteries associated with specific GI organs? Check all that apply.
mesocolon greater omentum faliciform ligament
Digested triglycerides are contained within the _____________ prior to being transported across the simple columnar epithelial lining of the small intestine into the epithelial cells.
micelles
Digestion begins in the
mouth
The mucosa of the esophagus is lined with ___________ squamous epithelium.
nonkeratinized stratified
DNA and RNA (nucleic acids) are polymers of nucleotides that are broken down, first, by pancreatic enzymes and then completed by intestinal brush border enzymes which include phosphatase and _____________.
nucleosidase
The _________ is a mixed gland with endocrine and exocrine functions that produces the majority of the digestive enzymes.
pancreas
The accessory organs of the lower GI tract include the liver, gallbladder, and
pancreas
Which of these are accessory organs of the GI tract? Check all that apply.
pancreas, gallbladder
The majority of triglyceride digestion occurs in the small intestine facilitated by the enzyme
pancreatic lipase.
Defecation is stimulated by
parasympathetic and local reflexes
Smooth muscle activity in the small intestine wall facilitates chemical digestion and absorption employing the processes of segmentation and
peristalsis.
The process of moving a bolus through the GI tract as a result of involuntary muscle contractions is referred to as
peristalsis.
Between the partietal and visceral peritoneum is the thin
peritoneal cavity.
Which organs and accessory structures are considered part of the upper GI tract? Check all that apply.
pharynx duodenum stomach esophagus
Which of the following is not a function of the digestive system?
production of ATP
Which of the following regions of the large intestine is a muscular tube that expands to store accumulated material prior to defecation, and terminates at the anal canal?
rectum
Which of the following structures are anatomically part of each tooth? Check all that apply.
root pulp enamel
Submucosal glands
secrete alkaline mucous
Enteroendocrine cells
secrete digestive hormones
Basic functions of the liver include
secretion, storage, and detoxification
Digestive reflexes that do not involve the central nervous system but instead are local and occur only within the enteric nervous system are called ________ reflexes
short
Most GI tract organs are lined with a ________ epithelium.
simple columnar
The stomach is lined by a
simple columnar epithelium
Check all that line the mucosa of the large intestine.
simple columnar epithelium globlet cells intestinal glands
During digestion, the major site of nutrient absorption is the
small intestine
Most nutrient absorption occurs in the
small intestine
The muscularis usually contains two layers of _____ muscle.
smooth
Hydrochloric acid is secreted in the
stomach
Which of these is an organ of the gastrointestinal tract as opposed to an accessory organ?
stomach
Which of the following might stimulate the cephalic phase of gastric secretion?
the thought of food
What are the serous membranes of the GI tract called? Check all that apply.
visceral peritoneum parietal peritoneum