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