The mechanical and chemical receptors that control digestive activity are located
in the walls of the tract organs
The function of the hepatic portal circulation is to
collect absorbed nutrients for metabolic processing or storage
The chemical and mechanical processes of food breakdown are called
digestion
When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. The series of reactions is called
chemical digestion
The sheets of peritoneal membrane that hold the digestive tract in place are called
mesenteries
From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. arrange them in order from the lumen
Mucosa, submucosa, muscularis externa, and serosa
Which of the following is not a factor that helps create the stomach mucosal barrier?
rennin
What part of the tooth bears the force of chewing?
enamel
The capillaries that nourish the epithelium and absorbs digested nutrients lie in the
lamina propria
Which hormone causes an increased output of enzyme-rich pancreatic juice and stimulates gallbladder contraction to release bile?
cholecystokinin
choose the incorrect statement regarding bile
Bile contains enzymes for digestion
The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task?
plicae circulares and intestinal villi
Select the statement that is true concerning primary teeth
there are 20 primary teeth, and by 24 months of age most children have all 20
Which of the following is true concerning the number and type of permanent teeth?
There are 32 permanent teeth, and the wisdom teeth are the last to emerge
Which of the following is not true of saliva?
contains enzymes that begin the breakdown of proteins
The salivary glands are composed of which two types of secretory cells
serous cells and mucous cells
the solutes contained in saliva include
electrolytes, digestive enzyme, mucin, lysozyme, wastes, and IgA
In addition to storage and mechanical breakdown of food, the stomach
initiates protein digestion and denatures proteins
chyme is created in the
stomach
hydrochloric acid is secreted by which of the secretory cells of the stomach
parietal cells
Gastrin, histamine, endorphins, serotonin, cholecystokinin, and somatostatin are hormones or paracrines that are released directly into the lamina propria. Which of the following cell types synthesize and secrete these products
enteroendocrine cells
these are three phases of gastric secretion. The cephalic phase occurs
before food enters the stomach and is triggered by aroma, sight, or thought
peristaltic waves are
waves of muscular contractions that propel contents from one point to another
Gastrin is digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulate by the presence of
protein and peptide fragments
pepsinogen, a digestive enzyme, is secreted by the
chief cells of the stomach
You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal
amylase
the ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the
hepatopancreatic ampulla
the enzymatic breakdown of any type of food molecule is called
hydrolysis
Short-chain triglycerides found infoods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible?
lipase
parietal cells of the stomach produce
hydrochloric acid
hepatocytes do not
produce digestive enzymes
which of the following is not a phase of gastric secretion
enterogastric
which vitamin requires intrinsic factor in order to be absorbed
B12
chief cells
are found in the basal regions of the gastric glands
Chemical digestion reduces large complex molecules to simpler compounds by the process of
catabolism
The___ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure
liver
If an incision has to be made in the small intestine to remove an obstruction, the first layer of tissue to be cut is the
serosa
The terminal portion of the small intestine is known as the
ileum
The dental formula for an adult is 2-1-2-3- what does the 1 stand for?
canine tooth
Digestion of which of the following would be affected the most if the liver were severely damaged
lipids
___ is locally regulated in the blood by the active from the vitamin D, which acts as a cofactor
calcium
Important peritoneal folds do not include the
round ligament
The lamina propria is composed of
loose connective tissue
_____ is not important as a stimulus in the gastric phase of gastric secretion
carbohydrates
Pancreatic amylase does not get to the small intestine via the
cystic duct
The function of the goblet cells is to
produce mucus that protects part of the digestive organs from the effects of powerful enzymes needed for food digestion
Which of the following is an essential role played by large intestine bacteria?
synthesize vitamin K and B-complex vitamins
Nervous control of gastric secretion is provided by
the vagus nerve and enteric plexus
Which of the following are types of papillae on the tongues that contain taste buds?
fungiform and circumvallate
Which of the following produce intrinsic factor?
parietal cells
Which of the following enzymes is specific for proteins
trypsin
surgical cutting of the lingual frenulum would occur in which part of the body
tongue
A fluid secreted into the small intestine during digestion that contains cholesterol, emulsification agents, and phospholipids is
bile
The layer of the digestive tube that contains blood vessels, lymphatic nodes, and a rich supply of elastic fibers is the
submucosa
which of the following is not characteristic of the large intestine
is longer than the small intestine
what stomach secretion is necessary for normal hemoglobin production in RBCs?
intrinsic factor
How are most nutrients absorbed through the mucosa of the intestinal villa
active transport driven directly or indirectly by metabolic energy
Select the correct statement about the regulation of gastric secretion
gastric secretion can be stimulated before food has entered the mouth
paneth cells
secrete enzymes that kill bacteria
select the correct statement about digestive processes
chyme entering the duodenum can decrease gastric motility via the enterogastric reflex
Chemical digestion in the small intestine involves
cholecystokinin (CCK), an intestinal hormones responsible for gallbladder contraction
select the correct statement about absorption
if intact proteins are transported across the villus epithelium, an immune response may be the generated
select the correct statement about electrolyte absorption
iron and calcium are absorbed mostly by the duodenum
You have just eaten french fries, buttered toast, ice cream, and whole milk. Which of the following glands would be active in helping you to digest this food?
the pancreas
The ingestion of the meal high in fat content would cause which of the following to occur?
Bile would be released from the gallbladder to emulsify the fat in the duodenum
The mucosa of the developing alimentary tube comes from
endoderm
A baby is admitted to the hospital with a history of projectile vomiting after each feeding. On examination, it is found that the sphincter controlling food passage from the stomach to the duodenum is thickened and does not open readily. Because of the baby's loss of gastric juice, his blood probably indicates
alkalosis
Hormones or paracrines that inhibit gastric secretion include
secretin
which of these not part of the splanchnic circulation
inferior vena cava
What is the process of digestion
Ingestion
propulsion
mechanical breakdown
digestion
absorption
defecation
select the correct statement about absorption
if intact proteins are transported across the villus epithelium, an immune response may be generated
alimentary canal
digests and absorbs food.
mouth, pharynx, esophagus, stomach, small/large intestine
accessory organs
teeth, tongue, gall bladder, salivary glands, liver, and pancreas.
produce secretin that helps break down food
layers of the alimentary canal
mucosa, submucosa, muscularis externa, serosa
anatomy of the oral cavity
The tongue
The salivary glands
A. ducts of sublingual gland
B. sublingual gland
C. Parotid gland
F. submandibular gland
splanchnic circulation
includes arteries that branch off the abdominal aorta to serve the digestive organs and hepatic portal circulation
intrinsic muscles
confined in tongue and not attached to bone
allows tongue to change its shape
extrinsic muscles
alters the tongue's position
they protrude it, retract it, and move it from side to side
lingual frenulum
secures the tongue to the floor of the mouth and limits its posterior movement.
filiform papillae
roughen the tongue surface. provides friction for manipulating foods.
enteric nervous system
the in-house nerve supply of alimentary canal.
enteric neurons
communicate widely with one another to regulate digestive system activity
peritoneum
most extensive serous membrane
visceral peritoneum
covers external surfaces of most digestive organs
parietal peritoneum
lines body walls
peritoneal cavity
slit like space containing a slippery fluid secreted by serous membrane
mesentery
double layer of peritoneum.
Provides routes for blood vessels, lymphs, and nerves to reach digestive viscera
holds organs in place
stores fat
function of The salivary gland
Cleanses the mouth
dissolves food chemicals
moistens food and helps compact it
contains amylase that begins the digestion of starchy foods
two types of secretory cells
serous and mucous cells
cardiac sphincter
a physiological sphincter
primary dentitions
upper jaw: 2 incisors, 1 canine, 2 molars/2 incisors, 1 canine, 2 molars X 2
20 teeths
permanent dentition
2 incisors, 1 canine, 2 premolars, 3 molars/ 2 incisors 1 canine, 2 premolars, 3 molars X 2
32 teeths
digestive processes of the mouth
the mouth ingests
Begins mechanical breakdown by chewing
intitiates propulsion by swallowing
starts the digestion of polysaccharides
The pharynx
food passes to the oropharynx, then to the laryngopharynx
The mucosa contains stratified squamous epithelium
the esophagus
esophageal hiatus: where it pierces the diaphragm
cardiac orifice: where it joins the stomach
anatomy of the stomach
buccal phase of swallowing
occurs in the mouth; voluntary
it ends when bolus leaves mouth and stimulates tactile receptors in the pharynx
Pharyngeal-esophageal phase
involuntary. controlled by medulla and lower pons. vagus nerves transmit motor impulses from the swallowing center to the muscles of the pharynx and esophagus
enterogastrones
secretes cholecytokinin (CCK) and secretin
alkaline tide
as acid is pumped into the stomach, HCO3- is exported into the blood
gastric glands
produce stomach secretion
parietal cells
found in apical region of glands. secretes HCL and intrinsic factor
pepsin
protein-digesting enzyme. activating of pepsin helps digest proteins, breakdown plant food and kills bacteria
chief cells
occurs in basal regions of the gastric glands. produces pepsinogen
cephalic phase of gastric secretion
occurs before food enters the stomach
gastric phase
releases gastric juice. 3-4hrs longs
occurs once food enters the mouth
intestinal phase
occurs with a brief stimulatory component followed by inhibition
enterogastric reflex
duodenum inhibits acid secretion through the enteric nervous system (short reflexes) and sympathetic and vagus nerves (long reflexes)
Gross anatomy of the liver
The Liver
produces bile for export to the duodenum
bile breaks fat into tiny particles to make it digestible.
bile leaves the liver through right and left hepatic ducts
Bile
yellow-green, alkaline solution containing bile salts, bile pigments, cholesterol, triglycerides, phospholipids, and variety or electrolytes.
Bile salts
primarily salts of cholic and chenodeoxycholic acids
bilirubin
chief bile pigment.
yellow waste product of the heme of hemoglobin formed during the breakdown of word out RBCs
gall bladder
stores bile that is not needed for digestion
covered by visceral peritoneum
pancreas
produces enzymes that breakdown all foodstuffs
pancreatic juices
proteases (protein)
amylases (starch)
lipase (fats)
nucleases (nucleic acids)
small intestine
3 sections
duodenum (10 inches)
jejunum (8ft)
ileum (12ft)
site for digestion and absorption
enteropeptidase
within the duodenum
activates trypsinogen to trypsin
retroperitoneal organs
organs that loses their mesentery and lies posterior to the peritoneum
intraperitoneal organs
organs that keeps their mesentery and remains in the peritoneal cavity
gross anatomy of large intestine
