A&P Ch.24 Digestive System
Mastication
Process by which teeth break food into smaller particles to increase the total surface area
Mucous
Protects lining of the stomach.
Mucus
Protects the lining of the esophagus
Name the outermost or most superficial layer of the organs in the digestive tract.
Serosa, Adventitia
Which of the following is not one of the major digestive secretions?
Serous fluid
Cephalic phase
Sight, smell, taste or thought of food stimulates gastric secretions
The superior portion of the esophagus consists of __________ muscle and the inferior portion consists of ___________ muscle.
Skeletal, smooth
Disaccharidases (enzyme)
Small intestine
Peptidases
Splits amino acids from polypeptides
Gastrin
Stimulates gastric secretions
the organ that secretes intrinsic factor is the ____________.
Stomach
Periodontal ligaments
Structures that secure the teeth in the alveoli
Fundus
The rounded superior portion of the stomach
The four parts of the colon from proximal to distal are the _________, __________, ___________, and the ___________ colon.
ascending, transverse, descending, and the sigmoid
From the duodenum through the ileum the diameter, number of villi, the thickness of the wall and the number of circular folds _______ and the number of lymphatic nodules ___________.
decreases; increase
The elimination of semi-solid waste products from the body is called
defecation
The process that moves a bolus from the oral cavity into the esophagus is called swallowing or ____________.
deglutition
The alimentary canal or tract is also know as the ______________ tract.
digestive
The regions of the digestive tract from beginning to end include the mouth, pharynx, ____________, stomach, ____________ _____________, large intestine and anus.
esophagus, small intestine
Food is ingested, digested and finally eliminated from the body as
feces
Pyloric part
funnel shaped part of the stomach
The organ that stores and concentrates bile is the _____________.
gallbladder
The openings in the mucous membrane of the stomach that contain gastric glands are called ___________ ___________.
gastric pits
The valve that allows intestinal contents to move from the ileum to the large intestine but not in the opposite direction is called the ______________ valve
ileocecal
Greater omentum
membrane extending from the stomach to the transverse colon.
The tunic of the digestive tract that forms its lining is the
mucosa
The inflammation of the peritoneal membranes is called ______________.
peritonitis
The internal anal sphincter consists of __________ muscle and the external anal sphincter consists of __________ muscle.
smooth, skeletal
Identify the organ of the digestive system that primarily functions as a storage and mixing chamber.
stomach
Which of the following are functions of the digestive tract? Select all that apply.
- Absorb electrolytes - Absorb water - Digest food
Identify the components of pancreatic juice.
- Enzymes to digest lipids - Enzymes to digest nucleic acids - Enzymes to digest carbohydrates - Bicarbonate ions - Enzymes to digest proteins
Identify the functions of mucus secretion in the large intestine.
- Lubricates colon wall - Helps fecal matter stick together - Protects intestinal lining
Identify the functions of saliva.
- Neutralizes bacterial acids - Digests starch - Moistens food and oral cavity
Identify the substances that aid in the chemical digestion of proteins.
- Pepsin - Peptidases - Trypsin - Carboxypeptidase
Identify the secretions of the small intestine.
- Peptidases - Disaccharidases - Mucus - Cholecystokinin - Secretin
Identify the types of movements that occur within the small intestine.
- Peristaltic contractions - Segmental contractions
Identify the functions of the various microorganisms that inhabit the colon.
- Production of flatus - Production of vitamin K - Breakdown cellulose
Identify the structures that secrete enzymes that aid in the chemical digestion of proteins.
- Stomach - Pancreas - Small intestine
Name factors that influence stomach emptying.
- The type of food - The volume of food; the more food in the stomach the longer it takes to empty
Identify the structures of the digestive tract that are lined with stratified squamous epithelium.
- esophagus - mouth - anal canal - Oropharynx
Describe the anatomy of the large intestine.
- lacks villi - lined with simple columnar tissue
Select the mechanisms that regulate the digestive system.
- nervous mechanisms - chemical signals
Identify the functions of the stomach
-Some chemical digestion of proteins -Storage and mixing chamber -Some chemical digestion of lipids
Describe the functions of hepatocytes. Select all the apply.
-phagocytosis -synthesis of blood components -detoxification -bile production
Places the events of the gastrointestinal phase of gastric regulation in order beginning with the initiation of the gastrointestinal phase.
1. Acidic chyme enters the duodenum. 2. Activation of nerve reflexes and the secretion of secretin 3. Inhibition of gastric activity
Place the events of the gastrointestinal phase of gastric regulation in order beginning with the initiation of the gastrointestinal phase.
1. Acidic chyme enters the duodenum. 2. Activation of nerve reflexes and the secretion of secretin. 3. Inhibition of gastric activity
Place the events of lipid transport across the intestinal epithelium in chronological order.
1. Bile salts surround fatty acids and monoglycerides to form micelles 2. Micelles attach to the plasma membrane of the intestinal epithelial cells. 3. Fatty acids and monoglycerides diffuse into the intestinal epithelial cells. 4. Fatty acids and monoglycerides are converted into triglycerides 5. Proteins coat triglycerides to form chylomicrons which move out of intestinal cells by exocytosis. 6. Chylomicrons enter lacteals of the intestinal villi.
Explain the process of bicarbonate ion production in the pancreas.
1. CO2 and H2O combine under the influence of carbonic anhydrase to form H2CO3- 2. Carbonic acid dissociates into H+ and HCO3- 3. H+ exchanged for Na+ in the blood. 4. HCO3- exchanged for Cl- in the intercalated ducts. Na+ and H2O follow the HCO3- 5. HCO3-, Na+ and H2O move into the interlobular ducts
Identify the ducts that bile passes through beginning with the gall bladder and ending with the small intestine.
1. Cystic duct 2. Common bile duct 3. Hepatopancreatic ampulla 4. Duodenum
Place the events of the gastric phase of gastric regulation in order, beginning with the activation of the gastric phase.
1. Distension of the stomach stimulates stretch receptors 2. Activation of central nervous system and enteric nervous system 3. Secretion of gastrin 4. Gastric secretions
Place the sections of the small intestine in order as food passes through the digestive tract.
1. Duodenum 2. Jejunum 3. Ileum
Identify the structures that blood will pass through as it passes through and out the liver.
1. Hepatic artery and hepatic portal vein 2. Hepatic sinusoid 3. Central vein 4. Hepatic vein 5. Inferior vena cava
Identify the structures that chyme will pass through, starting with the small intestine and ending with elimination
1. Ileocecal junction 2. Cecum 3. Colon 4. Rectum 5. Anal canal
Identify the ducts that pancreatic exocrine secretions will flow through beginning with the acini and ending with the small intestine.
1. Intercalated ducts 2. Intra-lobular ducts 3. Interlobular ducts 4. Pancreatic duct 5. Hepatopancreatic ampulla 6. Duodenum
Identify the tunics of the esophagus from inner- to outermost
1. Mucosa 2. Submucosa 3. Muscularis 4. Adventitia
List the tunics of the digestive tract from inside to outside.
1. Mucosa 2. Submucosa 3. Muscularis 4. Serosa
Place the events of the cephalic phase of gastric regulation in order beginning from initiation of the cephalic phase.
1. Taste, smell of thought of food 2. Stimulation of medulla oblongata 3. Parasympathetic impulses are carried by the vagus nerve to the neurons of the enteric plexus 4. Postganglionic neurons stimulate secretion of gastrin and histamine 5. Gastric secretions are released.
Place the following events of deglutition in order beginning with the voluntary phase of swallowing.
1. Tongue elevates bolus toward oropharynx 2. Soft palate closes off the nasopharynx 3. Successive contraction of superior and middle pharyngeal constrictors moves bolus through pharynx 4. Contraction o inferior pharyngeal constrictor relaxes upper esophageal sphincter and allows bolus to enter esophagus 5. Peristaltic contractions of esophagus move bolus through esophagus 6. Relaxation o flower esophageal sphincter
Place the following events of activation of proteolytic pancreatic enzymes in order.
1. Trypsinogen, chymotrypsinogen, and procarboxypeptidase are secred into the the duodenum. 2. Enterokinase activates trypsinogen 3. Trypsin activates trypsinogen, chymotrpsinogen, and procarboxypeptidase
Place the phases of deglutition in order from beginning to end.
1. Voluntary phase 2. Pharyngeal phase 3. Esophageal phase
Identify the layers of the mucosa from inside to outside.
1. mucous epithelium 2. lamina propria 3. muscularis mucosa
The majority of the muscularis consists of _____________ laters(s) of ____________ muscle.
2; smooth
Throughout the digestive tract, the muscularis consists of _________ layers of muscles except in the __________, which has 3 layers of muscles
2; stomach
The hepatic lobule is a ___________-sided structure with a(n) ___________ triad at each corner and a central vein located in the center of each lobule.
6; portal
Describe the cecum.
A rounded pouch located at the proximal end of the large intestine.
What is bile?
A substance produced by hepatocytes from metabolic by-products
The salivary glands, tonsils, liver, gall bladder, and pancreas are ___________ ____________ of the digestive system.
Accessory organs
Intestinal phase
Acidic chyme in the duodenum stimulates secretion of hormones that inhibit gastric secretions
Enterokinase
Activates trypsin
Central nervous system
Activation of reflexes due to sight, smell, or taste of food
Pepsinogen
Active form aids in breaking proteins into smaller peptide chains.
Intrinsic factor
Aids in the absorption of Vitamin B12 (in the small intestine)
Liver
Bile
Identify the components of bile.
Bile salts, lecithin, mucus, cholesterol, bilirubin
What are hepatic sinusoids?
Blood filled channels between hepatic cords
Digestion
Breakdown of large organic molecules into their component parts.
Dentin
Calcified living material surrounding the pulp cavity.
The names of the two minor lobes of the liver are the ___________ and ___________ lobes
Caudate, quadrate
The proximal end of the large intestine is characterized by a pouch-like structure called the ____________.
Cecum
Pulp cavity
Center of tooth filled with blood vessels, nerves and connective tissue
Lipids are absorbed from the intestinal tract into lymphatic capillaries as a droplet of triglycerides, phospholipids, cholesterol and protein known a(n)
Chylomicrons
submucosa
Consists of a thick layer of connective tissue containing nerves, blood vessels, lymphatics and glands
Serosa
Consists of a thin layer of connective tissue and simple squamous epithelium
Mucosa
Consists of an epithelial lining, a layer of connective tissue referred to as lamina propria and a thin layer of muscle
Cardiac sphincter
Constrictor between the esophagus and the stomach
Pyloric Sphincter
Constrictor between the stomach and the small intestine
Parasympathetic nervous system
Controls digestive activity and alters activity of the enteric nervous system through the vagus nerve
Enteric nervous system
Controls peristatic and mixing movements, glandular secretions, and blood flow in specific short regions of the digestive tract
Identify the three basic parts of a tooth
Crown, Neck, Root
Identify the process that moves a bolus from the oral cavity into the esophagus.
Deglutition
Hydrochloric acid
Destroys ingested bacteria and activates pepsin
Lipase
Digests lipids
Trypsin
Digests proteins
Pepsin
Digests proteins into smaller peptide chains
Identify the enzymes that aid in the chemical digestion of carbohydrates
Disaccharidases, amylase
Gastric phase
Distension of the stomach stimulates gastric secretions
Identify the two structures where the majority of nutrient absorption occurs.
Duodenum, jejunum
Why is emulsification of lipids important?
Emulsification increases surface area for digestive enzymes
Identify the functions of bile
Emulsification of lipids, Raises pH of small intestine
Bile salts
Emulsifies lipids
Chemical digestion
Enzymatic action that breaks larger organic molecules into smaller components
Mass movements
Forcible movements that move the contents of the large intestines.
Identify the organs of the digestive system that are considered accessory organs. (EVERYTHING EXCEPT FOR SMALL INTESTINE)
Gall bladder, pancreas, Salivary glands, liver, tonsils
Mixing waves
Gentle contractions that occur every 20 seconds that proceed from the body of the stomach toward the pyloric sphincter
Identify the secretions of the large intestine.
HCO3- , Mucous
Enamel
Hard non-living material covering the crown
Name the cells that produce bile, synthesize blood components, and perform interconversion of nutrients
Hepatocytes
Stomach
Hydrochloric acid, Pepsinogen
Mechanical digestion
Includes mastication and mixing of food
Sympathetic nervous system
Inhibits muscular contraction and secretions, and decreases blood flow of the digestive system
Identify the secretions of the stomach
Intrinsic factor, Gastrin, Pepsinogen, Hydrochloric acid, mucus
Identify the organs that are located behind the peritoneal membrane.
Kidneys, pancreas, duodenum
Body
Largest part of the stomach
Identify the parts of the pharynx that function in digestion.
Laryngopharynx, Oropharynx
Describe how lipids are transported through the blood.
Lipids are combined with protein to form lipoproteins
Bile salts (enzyme)
Liver
Identify the functions of the tongue.
Mastication, Swallowing, taste, speech
Lesser Omentum
Membrane that connects the stomach and the proximal end of the duodenum to the liver and the diaphragm.
Identify the features of the small intestine that function to increase surface area and thus enhance digestion and absorption.
Microvilli, Circular folds, Villi
Chemical digestion of carbohydrates results in the production of ________________.
Monosaccharides
Propulsion
Movement of food from one end of the digestive tract to the other
Absorption
Movement of molecules from the digestive tract into the circulation or lymphatic system.
Deglutition (swallowing)
Moves a mass of food or liquid from the oral cavity to the esophagus
Peristalsis
Muscular contractions consisting of a wave or relaxation of circular muscles followed by a wave of contraction of circular muscles.
Segmental contractions
Muscular contractions that move food back and forth within the digestive tract to mix it with digestive secretions (small intestine)
Glucose absorption across the intestinal epithelium occurs as a result of a symport with ___________
Na+
The muscles that forms the majority of the lips is the __________ and the muscle that forms the majority of the cheeks is the ___________.
Orbicularis oris, buccinator
Identify the process by which water is absorbed in the small intestine.
Osmosis
Serosa
Outer covering of the gall bladder.
Identify the organ of the digestive system composed of both endocrine and exocrine tissue located within the curvature of the duodenum.
Pancreas
Trypsin (enzyme)
Pancreas
Identify the structures that secrete amylase.
Pancreas, Salivary glands
Identify the types of reflexes that control the defecation reflex.
Parasympathetic reflexes, local reflexes
Identify the 3 large paired salivary glands.
Parotid, submandibular, sublingual
Clinical crown
Part of tooth exposed in the oral cavity
Small intestine
Peptidases
Identify the types of enzymes secred by the small intestine.
Peptidases, disaccharidases
What is the pyloric pump?
Peristaltic contractions that move chyme through the partially closed pyloric opening.
What are gallstones?
Precipitates of cholesterol that form in the gallbladder
Bicarbonate ions
Provides appropriate pH for pancreatic enzymes
Root canal
Pulp cavity within the root
Organs that are located behind the peritoneal membrane are referred to as _______________.
Retroperitoneal
Identify the folds of mucous membrane within the lining of the stomach that allow for stretching of the stomach.
Rugae
Identify the hormones that decrease gastric secretions and gastric motility.
Secretin, Cholecystokinin
identify the structures of the digestive tract that are lined with simple columnar epithelium.
Small intestine, large intestine, stomach
Identify the structures where lipid digestion occurs.
Small intestine, stomach
Stomach secretion and stomach motility are controlled by neural mechanisms that respond to ___________
Stomach wall distension
Peristaltic waves
Strong contractions that force chyme near the periphery of the stomach toward the pyloric sphincter
The submucosal plexus is located within the ___________ and the myenteric plexus is located within the ___________ of the digestive tract.
Submucosa; muscularis
Identify the 4 muscles of mastication.
Temporalis, lateral pterygoid, medial pterygold, masseter
Ingestion
The intake of solid or liquid food into the stomach
Describe emulsification.
The process by which bile salts transform large lipid droplets into much smaller droplets.
Describe the effects of food intake on the stomach.
The rugae flatten and the stomach volume increases.
How does the muscularis of the stomach differ from the muscularis of the majority of the alimentary canal?
The stomach has 3 layers of muscle in the muscularis and the majority of the digestive tract only has 2 layers of muscle.
Muscularis
Through most of the digestive tract, this tunic consists of two layers of smooth muscle; and inner circular layer, and an outer longitudinal layer
Muscularis
To allow for contraction of the gall bladder
Pancreas
Trypsinogen
The parasympathetic nervous system controls digestive functions and alters the activity of the enteric nervous system through the ____________ nerve.
Vagus
Identify the small blind-ended tube attached to the cecum.
Vermiform appendix
Identify the MACROscopic fingerlike projections of the small intestine that increase surface area for increased absorption.
Villi
The serous membrane that covers the organs of the abdominal cavity is the _____________ peritoneum.
Visceral
Identify the substances absorbed by the large intestine.
Vitamin K, Salt, Water
The structure of the digestive system that primarily consist of glands located outiside the digestive tract that secrete fluids into the digestive tract are known as
accessory organs
The two major divisions of the digestive system include the digestive tract and the ___________ ____________.
accessory organs
The majority of ion absorption occurs as a result of _____________.
active transport
The last section of the digestive tract that extends from the inferior end of the rectum and ends at the anus is the ________________ ____________________.
anal canal
permanent teeth replace milk or _____________ teeth.
baby
The region of the large intestine located at the proximal end, where the large intestine meets the small intestine is the _____________
cecum
The buccinator muscle, a buccal fat pad, an interior lining of moist stratified squamous epithelium, and an external covering of skin complete the _____________.
cheeks
The semi-fluid material within the stomach that is a mixture of ingested food and gastric secretions is called
chyme
Feces are eliminated from the body by the process of
defecation
The tongue, oropharynx and mouth are all involved with swallowing or _____________.
deglutition
Hepatocytes convert ammonia to urea which is more easily excreted from the body. This is an example of ______________.
detoxification
The two major divisions of the digestive system include ___________ _____________ and the accessory organs.
digestive tract
The majority of digestion occurs within the ____________.
duodenum
The pancreatic islets is the ____________ part of the pancreas and the acini is the ____________ part of the pancreas.
endocrine, exocrine
Most of the nervous control of the digestive system is through the __________.
enteric nervous system
The structure within the mediastinum, anterior to the vertebrae and posterior to the trachea is the
esophagus
Mucosa
folded into rugae to allow for expansion of the gall bladder
The saclike structure on the inferior surface of the liver is the _______________.
gallbladder
Mass movements in the colon are initiated by the ___________ reflex when there is food in the stomach and by the ____________ reflex when there is food in the small intestine.
gastrocolic; duodenocolic
The palate consists of two parts: the anterior portion called the __________ palate and the posterior portion called the ___________ palate.
hard, soft
The pouches of the colon that result from contraction of the teniae coli are called _______________
haustra
Norepinephrine
inhibits digestive tract motility and secretions
A chylomicron is a _____________ droplet surrounded by _____________.
lipid; proteins
Fatty acids and glycerol are products of the chemical digestion of ______________.
lipids
A micelle is ______________ droplet surrounded by ______________.
lipids; bile salts
The _______________ are formed mostly by the orbicularis oris and connective tissue covered by skin.
lips
The largest internal organ of the body is the
liver
Bile is continuously produced by the _______________; bile then flows to the _______________ bladder where it is stored and concentrated.
liver; gall
The strong and infrequent peristaltic contractions that move contents of the large intestine longer distances are called _____________ __________________.
mass movements
The process of chewing is called
mastication
"Connective tissue sheets composed of two layers of serous membranes with a thin layer of loose connective tissue between them" best describes
mesenteries
Chemical digestion of starch due to secretion of enzymes occurs in the ______________,
mouth, small intestine
When chyme is concentrated, water will ______________.
move into the lumen of the small intestine
Mucous neck cells of the stomach produce __________ and chief cells of the stomach produce _____________.
mucus, pepsinogen
In the liver excess amino acids can be re-metabolized to produce lipids, glucose or nucleic acids. This is known as _____________
nutrient interconversion
The ________________ is an organ that consists of a head located within the curvature of the duodenum and a tail that extends to the spleen.
pancreas
The structure indicated by the blue arrow is the ____________, a straight muscular tube that begins at the termination of the sigmoid colon and ends at the anal canal.
rectum
Internal and external anal sphincters promote defecation when the muscles ___________
relax
The abdominal cavity is lined by ______________ membranes which produce a thin, lubricating film.
serous
In the digestive system, the greatest amount of digestion and absorption occurs in the ________________ ___________________.
small intestine
The majority of lipid digestion occurs in the
small intestine
The majority of water absorption occurs in the
small intestine (duodenum)
Vestibule
space between the lips and teeth
Oral cavity proper
space medial to the teeth
Serotonin
stimulates digestive tract motility
Acetylcholine
stimulates motility and secretions
The layer of the digestive tract that consists of connective tissue containing nerves, blood vessels, lymphatic vessels, small glands and a network of nerve cells is the _____________.
submucosa
The bands of longitudinal muscle of the colon that form the haustra when they contract are called
teniae coli
The large muscular organ that occupies most of the oral cavity proper is the ______________.
tongue
The posterior projection of the soft palate is the ________________
uvula
Mesentery Proper
Associated w the small intestine
Transverse mesocolon
Attaches the transverse colon to the posterior abdominal wall
Identify the structures that aid in the chemical digestion of carbohydrates.
- Salivary glands - Small intestine - Pancreas
Identify the functions of the liver. (*except of pruduction of digestive enzymes)
- Synthesis of new molecules - Storage of glycogen, lipids, vitamins, and minerals - Phagocytosis _ Interconversion of nutrients (amino acids to carbohydrates) - Production of bile -Production of blood proteins including clotting factors -phagocytosis of worn out red and white blood cells -Detoxification of harmful substances
Identify the structures that form the hepatic portal triad.
- hepatic artery - hepatic portal vein - hepatic duct
Identify the steps in the production of hydrochloric acid by the stomach from beginning to secretion into the stomach.
1. CO2 diffuses into the parietal cell 2. CO2 combines with H2O to form H2CO3 3. H2CO3 dissociates into HCO3 and H 4. HCO3 is exchanged for Cl with the bloodstream 5. H pumped into the duct of the gastric gland 6. Diffusion of CL into duct of gastric gland
Place the events of the defecation reflex controlled by local reflexes in chronological order.
1. Gastrocolic and duodenocolic reflexes 2. Mass movements in colon propel contents towards the rectum 3. Distension of the rectum 4. Local reflexes stimulate contraction of colon and rectum and relaxation of internal anal sphincter
Rank the following molecules from the one with the greatest concentration of protein to the least amount of protein.
1. High- density lipoprotein 2. Low- density lipoprotein 3. Very low- density lipoprotein
LDL is considered __________ while HDL is considered ___________.
bad; good
The emulsification of lipids occurs primarily through the action of _____________ ________________.
bile salts
All of the microvilli on the epithelial surface of the small intestine are collectively called the ___________.
brush border
