Anatomy Ch.26 Digestion
What prevents stomach contents from spilling into the esophagus?
Lower esophageal sphincter
T or F: The stomach wall will relax when stretched.
True, the receptive-relaxation response describes how the stomach is stretched as food arrives, then it relaxes to accomodate the incoming meal.
List the pancreatic zymogens.
Trypsinogen, chymotrypsinogen, procarboxypeptidase
The source of the _________ ions in stomach acid is the dissociation of carbonic acid within parietal cells.
hydrogen
The valve at the junction of the small intestine to the large intestine is the _____ valve.
ileocecal
List two effects of the defecation reflex.
1. relaxation of the internal anal sphincter 2. Contraction of the rectum
Which of the following are hormone secretions of the gastric glands.
1. somatostatin 2. histamine 3. gastrin
Which vitamins are fat-soluble and are absorbed along with dietary fats, while the other vitamins are absorbed by simple diffusion?
A, D, E, K
The foramen through which nerves and blood vessels enter the tooth is called?
Apical foramen
Name the major bile component that is recycled via the enterohepatic circulation.
Bile acids
The hormone produced by enteroendrocrine G cells that stimulates stomach HCL and enzyme activity is?
Gastrin
Pouches that form the walls of the large intestine are called ?
Haustra
A form of segmentation that occurs in the large intestine is called?
Haustral contractions
Microscopic subunits of the liver, each consisting of a central vein passing down its core, are called?
Hepatic lobules
Define Kupffer cells.
Hepatic phagocytes
Name the duct segment that is formed when the bile duct and pancreatic duct merge?
Hepatopancreatic ampulla
Salivary glands dispersed among the oral tissues are classified as _________ glands.
Intrinsic
Define colon.
Large intestine from ileocecal junction to rectum.
What enzyme digests lipids?
Lipase. It has lingual, gastric and pancreatic forms.
Identify the structures that work together to retain food and push it between the teeth for chewing. They are also essential for speech, sucking, and blowing actions.
Lips Cheeks Tongue
Name the type of small intestine contractions that begin after digestion and absorption of nutrients is completed. They serve to move chyme toward the colon.
Migrating motor complex
List 2 enzymes that decompose nucleotides into phosphate ions, pentose sugars, and nitrogenous bases.
Nucleosidase Phosphatase
The duct that runs lengthwise through the pancreas, joining the bile duct at the hepatopancreatic ampulla is the _________ ________.
Pancreatic duct
Describe chemical digestion in the stomach.
Partial digestion of both protein and fat can occur in the stomach.
What phase of swallowing is involuntary?
Pharyngoesophageal
Describe the gastrocolic reflex.
Stretching of the stomach triggers colic motility
Describe mass movements.
Strong peristaltic contractions of large intestine occurring 1-3 times/day.
Define gastroenterology.
Study of the digestive tract
The paired nuclei in the medulla oblongata that control the act of swallowing are the ?
Swallowing centers
The left colic flexure is between?
The descending colon and transverse colon
The nuclei of the brainstem that receive signals from tactile, pressure, and taste receptors in the mouth that are stimulated by food are?
The salivatory nuclei
Describe function on intrinsic factor.
Transport and absorption of Vitamin B12.
Glucose and galactose are moved into absorptive cells via ______ while fructose is absorbed by _______.
Transporters; facilitated diffusion
T or F: After digestion and absorption into absorptive cells, fatty acids and monoglycerides are reassembled into triglycerides before being moved into the lymph.
True. While carbs and proteins remain in their digested state (monosaccharides and amino acids), triglycerides are reassembled before entering the lymph.
Name the muscular structure that remains closed when food is not being swallowed in order to exclude air from the esophagus.
Upper esophageal sphincter
Name the space between the lips and the teeth.
Vestibule
What refers to the small fingerlike projections of the lining of the small intestine?
Villi
Lacteal
a lymphatic capillary within the core of an intestinal villus, necessary for the absorption of lipids
Gatroileal reflex
a specific reflex triggered by food in the stomach. It enhances segmentation of the ileum and relaxes the ileocecal valve, allowing residue into the cecum
The process of uptake of nutrient molecule is known as?
absorption
Describe an autocatalytic effect of an enzyme:
an enzyme catalyzes production of more of itself
Trypsin
an enzyme that converts chymotrypsinogen to chymotrypsin and procarboxypeptidase to carboxypeptidase.
Enterokinase
an enzyme that converts trypsinogen to trypsin
The final three cm of the large intestine is called the?
anal canal
Bile canaliculi are located
between plates of hepatocytes in lobules
The pancreas secretes _________ into the duodenum in order to neutralize acid arriving from the stomach.
bicarbonate
Within the hepatic lobules, hepatocytes secrete bile into narrow channels called?
bile canaliculi
The primary bile pigment is called _______
bilirubin
The fringe of microvilli on the apical surface of an epithelial cell which serves to increase surface area for absorption is also known as?
brush border
The lingual papillae are best described as
bumps on the surface of the tongue
The large intestines begin with a pouch inferior to the ileocecal valve that is known as?
cecum
The branch of the aorta supplying blood to the stomach is the _________ trunk.
celiac
The living connective tissue covering the root of the tooth is the
cementum
Blood within the hepatic sinusoids drains into the
central vein
Gastric secretion in response to the sight, smell, taste, or thought of food occurs during the ________ phase of gastric function.
cephalic
The hormone _______ is secreted by the small intestine in response to the presence of fats in the small intestine.
cholecystokinin
The soupy mixture of semi-digested food formed in the stomach is known as?
chyme
Haustral contractions
contractions of the segments of the large intestine that promotes mixing of residue, water and salt absorption and the passing of residue distally
Bile drains from the gallbladder via a duct called the _________ duct.
cystic
What is the collective name for the many species of bacteria residing in the large intestine?
gut microbiome
The blood-filled channels between the layers of hepatocytes in the liver are called?
hepatic sinusoids
Gastric activity is moderated by the activity of the duodenum during the ________ phase of gastric function.
intestinal
The tubular glands within the mucosa and submucosa of the small intestine are called _________ __________.
intestinal crypts
Within the large intestine, mucus is secreted by goblet cells and
intestinal crypts
The lingual glands, labial glands, and buccal glands are examples of?
intrinsic salivary glands
Crohn disease
involves inflammation of the intestines, with granular lesions and fibrosis of the intestine.
The long reflexes that aid in regulation of the digestive tract can best be described as:
involving the vagus nerve and brainstem
In order to absorb the mineral ________, transferrin is required to transport it.
iron
what connects the lips to the gum?
labial frenulum
The ___________ ___________ does not secrete digestive enzymes, but does absorb water and electrolytes.
large intestine
The part of the mesentery that extends from the liver to the lesser curvature of the stomach is the ________ __________.
lesser omentum
The gastric rugae are best described as
longitudinal folds in stomach lining
Digestion of starch by amylase results in the production of:
maltose
The sheets of connective tissue that hold the abdominal viscera in place, provide passage for blood vessels and nerves, and contain lymph nodes and lymphatic vessels are?
mesenteries
The mesentery that runs from the transverse colon to the posterior abd wall is ?
mesocolon
In the small intestine, the products of fat digestion are collected into ______, which are droplets of fat products surrounded by bile acids.
micelles
Messages are carried to adjacent regions of the GI tract by short reflexes via the __________ nerve plexus of the enteric nervous system.
myenteric
Water is absorbed through the process of ______, following the absorption of salts and organic nutrients.
osmosis
the salivary gland located just beneath the skin anterior to the earlobe is the _________ salivary gland.
parotid
Chylomicrons
particles that transport fats into lymph and blood
The enzyme _________ begins digestion of protein in the stomach.
pepsin
List 4 components of gastric juice
pepsin water HCl lipase
The predominant type of involuntary muscle contraction occurring in the stomach is called?
peristalisis
define the term enteric:
pertaining to the intestines
the pulp of a tooth is found within the?
pulp cavity
The muscular band that regulates the passage of chyme from the stomach to the duodenum is the ________ _________.
pyloric sphincter
Describe the effect of Ach (parasympathetic stimulation) on the pancreas.
secretion of enzymes
The mucosa of the colon is primarily lined with ________ ________ epithelium.
simple columnar
Minerals in the diet are absorbed from the:
small intestine
Vitamin B12
so large it can only be absorbed if it binds to intrinsic factor
Dextrinase, glucoamylase, and maltase complete the digestion of:
starch
The salivary gland located halfway along the body of the mandible, medial to its margin is the _________ salivary gland.
submandibular
The blind tube at the end of the cecum filled with lymphocytes and immune cells is
the appendix
major duodenal papilla
the fold of tissue at the termination of the hepatopancreatic ampulla
Greater omentum
the part of the mesentery that extends from the greater curvature of the stomach and loosely hangs over the small intestine like an apron
Role of micelles
to transport fats in the intestine to the surface of the enterocytes
what nutrients are absorbed without being digested?
vitamins and minerals
Dentin
yellowish tissue forming the bulk of the tooth
List the mechanisms that protect the stomach lining from the acidic environment.
1. mucous coat 2. tight junctions between epithelial cells 3. epithelial cell replacement
Identify the functions of saliva:
1. Aids in swallowing 2. Inhibits bacterial growth 3. Dissolves molecules so they can be tasted
List the nervous components that mediate the defecation reflex.
1. Myenteric nerve plexus 2. Parasympathetic nervous system
List the components of the pulp found within teeth.
1. blood and lymphatic vessels 2. Nerves 3. Loose connective tissue
List the four lobes of the liver.
1. caudate 2. quadrate 3. right 4. left
Name the enzymes that are located within the plasma membranes of enterocytes of the small intestine.
Brush border enzymes
The region of the stomach just inside the stomach entrance is the?
Cardiac region
Name the hormone secreted by the mucosa of the small intestine that stimulates gallbladder contraction and pancreatic enzyme release.
Cholecystokinin
The ______ of the pancreas secrete sodium bicarbonate, while the ________ of the pancreas secrete digestive enzymes.
Duct cells, acinar cells
Glands that secrete bicarbonate-rich mucus into the duodenum are?
Duodenal glands/Brunner glands
The distention of the duodenal wall initiates motility of the colon via the _________ reflex.
Duodenocolic
The ________ center of the medulla oblongata is involved in the process of vomiting.
Emetic
In order to improve fat digestion, large fat globules must first be dispersed into smaller droplets in a process called?
Emulsion
Define nucleases.
Enzymes that digest RNA and DNA.
T or F: A typical meal is emptied from the stomach within 1-2 hours.
F, can take up to four hours for a meal to clear the stomach.
T or F: The role of the liver in digestion is to produce digestive enzymes.
F, live produces bile for fat emulsion. It is the pancreas that produces digestive enzymes.
T or F: The stomach is innervated by parasympathetic, but not sympathetic, fibers.
False, both branches of the ANS innervate the stomach, the PSNS stimulates the digestive system and the SNS inhibits it.
T or F: Enamel covers the surface of the crown and the root of each tooth.
False. While enamel covers the crown, a connective tissue layers called cementum covers the root.
another name for the act of swallowing is
deglutition
Describe gastric pits.
depressions in gastric mucosa
The portion of the large intestine found between the transverse and sigmoid colon on the left side of the abd cavity is the _________ _________.
descending colon
The acini of the pancreas secrete ______, while the duct cells of the pancreas secrete ________.
digestive enzymes, sodium bicarbonate
The two-layered membrane extending from the midline of the posterior abd wall to the digestive tract is the _________ mesentery.
dorsal
The network of nervous tissue within the wall of the alimentary canal is called the ________ nervous system.
enteric
What means pertaining to the intestines?
enteric
The ________ reflex involves the duodenum sending signals, typically inhibitory, to the stomach.
enterogastric relfex
The ligament that separates the right and left lobes of the liver is the ______ _______.
falciform ligament
Chylomicrons are formed by the absorptive cells and are made up of _________ coated with phospholipds and protein.
fats
The function of the pharyngeal constrictors is to
force food downward when swallowing
A typical meal is emptied from the stomach within _____ hours.
four
List examples of hormones produced by the digestive tract
gastrin and secretin
List some of the functions of stomach acid:
1. denature proteins in food 2. activate pepsin and lingual lipase 3. destroy pathogens
List some components of saliva:
Lysozyme amylase lipase mucus water
The physical breakdown of food into smaller particles (by processes such as chewing and segmentation) is known as _____ digestion.
Mechanical
The irregular opening in the liver that forms a point of entry for blood vessels and exit for bile vessels is the?
Porta hepatis
Name the narrowed distal region of the stomach.
Pyloric region
Describe the location of bile ductules.
Within hepatic triads between lobules
periodontal ligament
collagen fibers holding teeth in place
The term used to specify the part of the large intestine that excludes the cecum, rectum and anal canal is the ?
colon
What is the narrow passage from the stomach into the duodenum?
pylorus
The portions of the large intestine that are located in the pelvic cavity are the ?
rectum and anal canal
Flatus
refers to the gas produced by intestinal bacterial that is expelled each day.
A structure that is located against the posterior body wall and only covered with peritoneum on its anterior side is said to be:
retroperitoneal
within the narrow area in the lower root of a tooth is a space occupied by the pulp, called?
root canal
Lingual lipase is produced by the ________, but not activated until it reaches the acid stomach.
salivary glands
The hormone ________ is released in response to acidity in the small intestines and stimulates the pancreas to secrete sodium bicarbonate solution (to neutralize the acidity).
secretin