Chapter 26 Flashcards
____ is the introduction of solid/liquid into the oral cavity.
ingestion
_____ is the voluntary/involuntary muscular contractions for mixing and moving materials through GI tract.
motility
____ is the production/release of digestive enzymes, acid, and bile into the GI tract to aid in digestion.
secretion
_____ is the breakdown of ingested food into smaller structures.
digestion
______ is when food is physically broken down and there are no chemical changes.
mechanical digestion
_______ involves specific enzymes to break chemical bonds, making smaller molecules for absorption
chemical digestion
_____ is the membrane transport of digested molecules, electrolytes, vitamins and water from GI into blood/lymph
absorption
______ is the expulsion of indigestible components
elimination
The mucosa is made of three layers: ______, ______, and _______.
epithelium, lamina propria, muscularis mucosae
The inner most layer of the mucosa is called the _____.
epithelium
Most of the GI tract (stomach, small and large intestines) are made of _______.
simple columnar epithelium
The cells of the oral cavity, or/laryngopharynx, esophagus, and anal canal are called ______.
nonkeratinized stratified squamous
The middle layer of the mucosa is called the ______.
lamina propria
The lamina propr. contains blood and lymphatic vessels, nerves and _______.
MALT
The outermost layer of the mucosa is the _____
muscularis mucosae
Which layer of the the mucosa facilitates the release of secretions from the mucosa into the lumen?
muscularis mucosae
Muscularis mucosae causes slight movement of mucosa to increase ______.
contact with materials within the lumen.
The submucosa is made up of _____ and ______.
areolar
dense irregular connective tissue
The submucosa contains large blood vessels, lymph vessels, _____ and ______.
nerves and glands
The submucosa contains ______, _____ in small intestines.
MALT, peyer’s patches
The submucosal nerve plexus innervates smooth muscle and glands of mucosa as well as glands of __________.
submucosa
The two lanes of the muscular?
inner circular layer
outer longitudinal layer
The inner circular layer surrounds the _____.
GI tract
The outer longitudinal layer runs the _____ of the GI tract.
length
The my centric nerve plexus is located between what two layers?
inner circular layer and the outer longitudinal layer
The mycentric nerve plexus contains both motor neurons of ANS and ________.
visceral sensory neurons
The functions of the muscularis?
peristalsis and mixing
______ is the alternating contraction sequence causing the pushing of ingested materials through the GI tract.
peristalsis
____ is the kneading motion within different regions of GI tract that lack directional movement.
Mixing
Serosa/Adventitia are both composed of _____.
areolar connective tissue
______ covers portions of the GI tract located outside of peritoneal cavity.
adventitia
The retroperitoneal organs
duodenum
pancrea
ascending/descending colon
rectum
The _____ is covered by visceral peritoneum.
serosa
The serosa covers portions of GI tract within the ______ cavity.
peritoneal
Intraperitoneal organs
stomach
jejunum/ileum
transverse/sigmoid colons
The digestive system is regulated by receptors, nervous control and _____.
hormonal control
_____ detect stretch or pressure.
baroreceptors
______ detect presence of specific substances.
chemoreceptors
Hormonal control is regulated by gastrin, secretin and ____.
cholecystokinin or CCK
Gastrin is released from the ____.
stomach
______ and ________ comes from the small intestines.
secretin
choleycystokinin
_______ control through facial, glossopharyngeal and vagus nerves.
Autonomic
________ nervous system contains both submucosal and myenteric nerve plexi.
enteric
____- nerve stimulates myenteric plexus which stimulates submucosal plexus.
Vagus
____ nervous can direct all essential activities of the GI tract in the absence of the ANS.
enteric
Daily secretions of ____ range between 1 and 1.5 liters, with most produced during mealtime.
saliva
Saliva is composed of ____% water and a mixture of solutes.
99.5%
_____ is made up of water and salivary amylase, mucin, and ______.
lysozyme
Saliva functions to ____ ingested food.
moisten
Saliva intiates ______.
chemical digestion
Saliva helps to form a _______ of the food that has been ingested.
food bolus
_____ initiates chemical digestion and ______ targets starch.
Saliva
salivary amylase
Saliva acts as a _____ so food molecules dissolve into saliva before they can stimulate taste receptors.
watery medium
Saliva cleans the _____.
oral cavity
Saliva helps inhibit _____ because it contains antibacterial substances: both lysozyme and IgA’s.
bacterial growth
The brains contains _______.
salivary nuclei
______ stimulation keeps oral cavity moist.
parasymphathetic
Parasympathetic stimulation keeps the oral cavity moist. The ____ nerve stimulates the submandibular and sublingual glands. The _____ nerve stimulates the parotid gland.
facial nerve
glossopharyngeal nerve
More saliva will be released in the upper GI in response to chemoreceptors and _____.
mechanoreceptors
Arrival of food into the stomach, especially ____ or ____ stimulates the release of more saliva.
spicy or acidic
Introduction of substances into oral cavity, especially ______ substances will release more saliva in response to super GI chemoreceptors and mechanoreceptors.
acidic
Saliva stimulation occurs when the higher brain centers thought, smell or _____ of food.
sight
______ stimulation results in more viscous saliva by decreasing water content.
sympathetic
_______ is the mechanical digestion in the oral cavity (chewing).
mastication
Mastication centers located within the _____ and _____ regulate coordinated activity of the teeth and the skeletal muscles of the lips, tongue, cheeks, and jaw.
pons and medulla
Mastication reduces the _____ into smaller particles to facilitate swallowing.
bulk
Mastication promotes salivation to help _____ and moisten food into bolus.
soften
Small, ____ molecules can be absorbed directly into the blood from the mouth without chewing or swallowing.
nonpolar
Between 6 and 30 months of age, ____ deciduous teeth will appear (including incisors, canines, and premolars)
20
All 20 deciduous teeth are lost and replaced with ____ permanent teeth (includes all deciduous teeth and molars).
32 permanent
Incisors most anterior, are shapes like chisels and have a ____ root.
single
_______ are designed for slicing or cutting.
incisors
Canines have ____ and a single root.
pointed tip
_______ are designed for puncturing and tearing.
canines
Premolars have a _____ with cusps and 1 or 2 roots.
flat crowns
Premolars are designed for ______ and ______.
crushing and grinding
Molars that are most posterior, have large crowd flat crowns with ____ or more roots.
3
______ are adapted for grinding and crushing.
Molars
The number of each type of tooth is written as a ________ for one quadrant of the mouth (upper and lower shown on separate rows)
dental formula
A dental formula for most adults
ICPM = 2123/2123
A dental formula for most children
ICP = 212/212
_______ or swallowing, is the process of moving ingested materials from the oral cavity to the stomach.
deglutition
The three phases of deglutition.
- voluntary phase
- pharyngeal phase (involuntary)
- Esophageal phase (involuntary)
_______ in the medulla coordinates with the respiratory center (also in the medulla) so there is a pause in breathing.
swallowing center
______ is difficulty swallowing.
dysphagia
If there is damage to the swelling center, the _____ can maintain function.
enteric nervous system
Voluntary Phase of Deglutition
Controlled by the cobra cortex
Chewed food forms bolus and then pushed superiorly against the hard palate
Transverse palatine folds direct bolus toward oropharynx initiating
Pharyngeal Involuntary Phase (1 second)
Swallowing center receives signals from tactile sensory receptors which causes:
Elevation of soft palate and uvula blocking off nasopharynx
Elevation of larynx resulting in epiglottis covering laryngeal opening
Bolus moves through pharynx to esophagus
Esophageal Involuntary Phase
5-8 seconds long as bolus moves through esophagus by peristaltic waves
______ is a normally collapsed, tubular passageway.
esophagus
The ________ contains superior and inferior sphincters which are normally closed, only opening to allow for the passage of a bolus.
esophagus
The _____ of the esophagus is unique and contains both skeletal and smooth muscle.
muscularis
The superior 1/3rd of the esophagus contains only _____. The muscle propels swallowed material out of pharynx quickly for the next ______ to occur.
skeletal muscle fibers
breath
The middle 1/3rd of the esophagus contains _________.
both skeletal and smooth muscle
The inferior 1/3rd of the esophagus contains ______ which is continuous with the muscular that extends throughout the stomach.
smooth muscle
The ____ is inferior to the diaphragm, anterior to the pancreas and the holding sac is in the left upper quadrant.
stomach
The stomach mixes ______ with secretions released from the stomach wall.
ingested food
The stomach mechanically digests the contents into a semifluid mass called _____.
chyme
The stomach completes _______ of both protein and fat.
chemical digestion
Absorption in the stomach is limited to small, non polar substances such as _____ and ______.
alcohol and aspirin
One essential function of the stomach is the release of the ______.
intrinsic factor
The intrinsic factor is needed for the absorption of vitamin _____ in the ileum of the small intestines.
B12
There are ___ types of secretory cells of the gastric epithelium.
five
In the stomach, four of the five secretory cells of the gastric epithelium produce _____ of gastric juices a day.
3 liters
The fifth secretory cells of the gastric epithelium secretes _____.
a hormone
_____ cells line the stomach lumen, extend into gastric pits.
surface mucous cells
Surface mucous cells secrete _____ product within mucin to surface where mucin hydrates and becomes a mucus layer. This prevents ulceration of the stomach lining.
alkaline
The ____ cells prevents ulceration of the stomach lining.
surface mucous
_____ cells line the base of gastric pits into the gastric glands, inter mixed with parietal cells.
mucous neck cells
Mucous neck cells produce an _____ which helps maintain the acidic conditions resulting from the secretion of the HCl.
acidic mucin
The mucous neck cells still act a a _____.
protective layer
_____ cells release intrinisic factor.
parietal cells
_____ is a glycoprotein required for the absorption of vitamin B12 needed for production of normal erythrocytes.
intrinsic factor
B12 deficiencies can result in ______.
pernicious anemia
______ cells release hydrochloric acid.
Parietal cells
Hydrochloric acid is not formed in parietal cell, forms in _______ after H+ and Cl- released from cell.
lumen
Normal stomach pH levels range from ______.
1.5 - 2.5
Hydrochloric acid converts inactive pepsinogen into active _____.
pepsin
______ kills most microorganisms that enter the stomach.
Hydrochloric acid
Hydrochloric acid contributes to the breakdown of plant cell walls and ______.
animal connective tissue
______ cells are the most numerous within gastric glands.
chief cells (peptic)
Chief cells (peptic) produce and secrete packets of _____ containing the inactive form of pepsin, pepsinogen.
zymogen granules
Chief cells are activated by both HCl and other _______.
active pepsin molecules
______ chemically digests denatured proteins into small peptide fragments.
Chief cells (peptic)
Chief cells produce ______, which is an enzyme with limited role in fat digestion (10% - 15%)
gastric lipase
______ are distributed throughout gastric glands.
G-cells
_____ secrete gastrin into the blood.
G-cells
G cells secreting gastrin stimulates _______ and secretions
stomach motility
Three stimulatory molecules responsible for HCl regulation; _______, ________, and _________.
acetylocholine
gastrin
histamine
______ is a neurotransmitter from enteric neurons.
acetylcholine
_____ is a paracrine hormone released from ECL cells.
histamine
_______is a hormone released from G cells.
gastrin
______ and _______ stimulates parietal cells directly.
histamine and acetylcholine
Gastrin stimulates release of histamine from ______ to indirectly stimulate parietal cells.
ECL cells
Somatostatin released from enteroendocrine cells when pH of stomach is ______.
too low
______ inhibits acid secretion by directly affecting parietal, ECL, and G cells.
Somatostatin
______ is the mixing of bolus with gastric juice to form chyme.
gastric mixing
_______ is the movement of acidic chyme from stomach through pyloric sphincter into duodenum.
gastric emptying
stomach motility steps
?
Peristaltic wave establishes a _________ on contents in pylorus than pressure exerted by pyloric sprinter to stay closed.
greater pressure on contents
Stomach motility causes ____ to empty into small intestines at a time.
3 mL
Peristaltic wave passes sphincter changing the _____.
pressure gradient back
greater pressure at sphincter than against contents thus sphincter closes causing a ________.
retropulsion
_______ is the movement of stomach contents out of sphincter back into stomach lumen.
retropulsion
The stomach contains pacemaker cells which spontaneously depolarize less than _____ times per minute and establish its basic rhythm.
4 times
Electrical signals spread via gap junctions, smooth muscle in ______ is a single unit.
muscularis
Nervous and hormonal regulation can alter the _______ but not rate, as well as secretory activity of the gastric glands.
force of contraction but not rate
The three phases of gastric secretion
Cephalic
Gastric
Intestinal
______ and ______ phases occur before and during a meal.
cephalic and gastric
_____ phase involves events that occur after the meal.
intestinal
The cephalic phase involves the ______.
cephalic reflex
The cephalic reflex is initiated by the _____, smell, sight, or taste of food.
thought
The cebral cortex sends signals to the _____, which passes the signal onto the medulla during the cephalic phase.
hypothalamus
During the cephalic phase the medulla increases ____ stimulation through the Vagus nerve to the stomach.
parasymphatetic
The stomach increases ______ from the gastric glands.
both the force of contraction and the secretion
Steps of cephalic phase
?
Steps of Gastric phase
?
______ is initiated when food enters the stomach.
gastric reflex
During the gastric phase ____ detect stretch.
baroreceptors
During the gastric phase _____ detect protein and increase in stomach pH.
chemoreceptors
During the gastric phase, signals trigger the medulla same as _______.
the cephalic reflex
During the gastric phase, the release of gastrin occurs due to the ______.
presence of food (protein)
Gastrin circulates back to the stomach to stimulate contractile activity of _____.
stomach wall
Gastrin circulates back to the stomach to release ______.
gastric secretions (HCl0
Gastrin circulates back to the stomach to stimulate contraction of pyloric sphincter to ______.
slow stomach emptying
Steps of the Intestinal phase
?
The purpose of the intestinal phase is to ____ stomach emptying to allow for adequate time for digestive processes.
slow
______ opposes cephalic and gastric reflexes.
intestinal reflex
The intestinal reflex is ignited upon entry of _____ into the duodenum.
acidic chyme
The intestinal reflex causes decreased force of ______ and release of secretions.
contractions
During the intestinal reflex there are decreased signals sent to _____ which decrease signals sent through the vagus nerve.
medulla
____ is released in response to fat.
CCK or cholecystokinin
_____ is released in response to a acidic chyme.
secretin
Both CCK and _____ inhibit parietal, ECL, and G cells as well as decreasing force of contractions.
secretin
Ingested nutrients spend at least 12 hours within the ____.
small intestines
The small intestines finishes _______.
chemical digestion
The small intestines function to abbrs. vitamins, all nutrients, and ______.
large portion of water/electrolytes
The small intestines consists of three segments: ________, _________, and ____________.
duodenum, jejunum, and ileum
Mucosa and submucosa create _______ that extend into the lumen.
circular folds
Circular folds are most numerous in the ______ and _____.
duodenum and jejunum
______ increase the surface area through which nutrients are absorbed.
circular folds
Circular folds act like _____ to slow movement of chyme.
speed bumps
____ are finger like projections of the mucosa that extend from circular folds of the SI due to the shorter length of the muscular mucosae.
Villi
Villi are most numerous in the _____ and increase surface area beyond circular folds.
jejunum
Each _____ contain ans arteriole, a capillary network, a venule, and a lacteal.
villi
_____ absorb lipid and lipid-soluble vitamins that can’t be absorbed into the blood stream.
Lacteals
______ also called a brush border.
microvilli
______ are extensions of plasma membrane of the simple columnar cells lining the small intestines.
microvilli
_____ further increase surface are beyond circular folds and villi.
microvilli
_______ are various enzymes embedded within the brush border that complete the chemical digestion of most nutrients immediately before absorption.
brush border enzymes
______ are located between the villi of the mucosa.
intestinal glands/crypts
Intestinal glands/ crypts contain 3 types of cells.
goblet cells
unicellular gland cells
enteroendocrine cells
____ produce mucin and increase in number from duodenum to ileum.
goblet cells
_______ cells synthesize enteropeptidase.
unicellular gland cells
______ release CCK and secretin.
enteroendocrine cells
Proximal duodenum also contains submucosal glands which secrete a viscous, alkaline mucus to protect the _______ for the acidic chyme.
duodenum
The motility of the small intestines is responsible for mixing chyme with ______ called segmentation.
accessory gland secretions
The motility of the small intestines is responsible for moving the chyme continually against new areas of the ______
brush border
The motility of the small intestines propels the contents through the small intestines toward the _____ which is called peristalsis.
large intestines
______ reflex is the movement of contents from ileum to cecum.
gastroileal reflex
In the gastroileal reflex the steps
ileum contracts ileocecal sphincter relaxes cecum relaxes contents moved from ileum to cecum ileocecal sphincter contracts
The gastroileal reflex is ignited by food _____.
entering the stomach.
The _____ is the largest internal organ and weighs 2-4 lbs.
liver
The liver is located in the _____.
right upper quadrant
_____ is the site where blood vessels, lymph vessels, bile ducts and nerves extend from the liver.
porta hepatis
The two blood sources for the liver are the ______ and ________.
hepatic artery and the hepatic portal vein
The ______ is the branch of celiac trunk, transports oxygenated blood.
hepatic artery
The ________ transports deoxygenated and nutrient rich blood from the GI tract, spleen, and pancreas.
hepatic portal vein
_____% of the blood volume to the liver comes from the hepatic portal vein.
75%
Blood mixes as it passes into the ______.
hepatic lobules
_____ are microscopic polyhedral sections of the liver, created by the liver’s CT capsule branching into the organ.
hepatic lobules
Hepatic lobules contain what 4 things?
hepatocytes
portal triads
central vein
hepatic sinusoids
Liver cells
hepatocytes
along the edges of hepatic lobules - have a bile ductule and branches of hepatic portal vein and hepatic artery.
portal triads
_____ drains blood flow from lobule
central vein
______ are thin walled capillaries within the hepatic lobules.
hepatic sinusoids
Venous blood from hepatic portal system and arterial blood are mixed within _______.
hepatic sinusoids
____ are absorbed from the sinusoids and enter the hepatocytes before blood leaves through the central vein.
nutrients
_____ are located within the sinusoids are macrophages and engulf harmful substances
kupffer cells
Bile produced by hepatocytes empty into ______.
bile canaliculi
______ is a sac like organ attached to inferior surface of liver that stores, concentrates and releases bile that the liver produces.
gallbladder
The gallbladder contains ___ tunics.
3
The three tunics of the gallbladder include: _______, _______, and ________.
mucosa, muscularis, and serosa
The gallbladder can hold ______ of bile.
40 - 60 mL
_____ contains water, HC03-, bile salts (formed from cholesterol) and mucin.
bile
Bile is produced at a rate of ______ L/day.
0.5 - 1 liter a day
The function of bile is _______.
emulsification
_______ is the mechanical digestion of lipids allowing more efficient chemical digestion of triglycerides.
emulsification
The ______ has both endocrine and exocrine functions.
pancreas
The length of the pancreas is ____ in length and retroperitoneal.
5-6 inches in length
The head of the pancreas near the duodenum curvature then extends to the left where the tail of the pancreas approaches the _____.
spleen.
Acing cells are located in the ____.
pancreas
Acinar cells are arranged in acini and produce/release _____.
digestive enzymes
Acinar cells release ____ to digest starch.
pancreatic amylase
Acinar cells release _______ to digest triglycerides.
pancreatic lipase
Acinar cells release ______ needed for protein digestion.
inactive proteases
Acinar cells release ___ for digestion of nucleotides.
nucleases
Simple cuboidal cells lining the pancreatic ducts secrete ________ fluid.
alkaline HC03- fluid
Fluid and enzymes mix to create _______ of pancreatic juices.
1-1.5 L/day
Cephalic and ____ phases stimulate release of pancreatic juice.
gastric
_____ is released due to fat content of chyme.
CCK
CCK stimulates smooth muscle in gallbladder wall to cause release of ___.
bile
_____ stimulates the pancreas to release enzyme rich pancreatic juice.
CCK
CCk relaxes _______ of hepatopancreatic ampulla.
smooth muscle
______ causes release of alkaline solution from the liver and ducts of the pancreas.
secretin
CCk and secretin also inhibit parietal, ____ and G cells, decreasing the release of ____ in the stomach.
ECL
The ______ absorbs water and electrolytes (NA+ and Cl-) primarily from remaining digestive material.
large intestines
The large intestines absorbs vitamin ___ and ____ which are synthesized by bacteria in the large intestines.
B and K
The three major regions of the large intestines
cecum
colon
rectum
The ____ is the first portion of the large intestines which extends inferior to ileocecal valve.
cecum
The vermiform appendix is located in the _____ and its suggested function is to contain bacteria helpful to colon.
cecum
The ____ has four segments: ______, ______, ______, and ______,
colon
ascending, transverse, descending, sigmoid colon
The _____ (part of mesentery) attaches each section to posterior abdominal wall.
mesocolon
The _____ is the muscular tube that readily expands to store accumulated feces.
rectum
The anal canal contains internal (_____) and external (______) anal sphincters.
smooth muscle
skeletal muscle
The mucosa of the large intestines is lined by ______ with goblet cells.
simple columnar
The mucosa of the _____ is smooth and lacks villi.
large intestines
The mucosa of the large intestines contains intestinal glands which _____.
secrete mucin
_______ are the numerous normal bacterial flora which inhabit the large intestines.
indigenous microbiota
_____ is responsible for chemical breakdown of complex carbs, proteins, and lipids that remain once chyme passed onto large intestines.
indigenous microbiota
Indigenous microbiota produces _____.
vitamin B and K
Indigenous microbiota produce H+, hydrogen sulfid, methane, and _______.
indoles and skatoles
Peristalsis in the large intestines is ______, but resembles peristalsis elsewhere.
weak and sluggish
____ is when the relaxed haustrum fill with digested material until distended, a reflex is triggered to contract the muscular.
haustral churning
_____ is powerful, peristaltic-like contraction involving the teenier coli.
mass movement
The function of mass movement is to propel fecal material toward the ____.
rectum
____ starts in the middle of the transverse colon.
mass movement
Mass movement occurs ____ times a day, often during or immediately after a meal.
2-3 times
Regulation of the large intestines is controlled by which two reflexex?
gastrocolic reflex
defecation reflex
_______ is ignited by stomach dissension to cause a mass movement.
gastrocolic reflex
_______ causes the elimination of feces from the GI tract.
defecation reflex
The _____ is ignited by baroreceptors in the rectal walls due to stretching.
defecation reflex
Conscious decision sends signals from the cerebral cortex to the external anal sphincter to relax and ______ is initiated.
Valsalva maneuver
Parasympathetic signals increase causing sigmoid colon and rectum to contract and internal anal sphincter to ____.
relax
Signal synapses in spinal cord with parasympathetic ________.
motor neuron?
________ are substances that must constitute part of the edit for survival
essential nutrients
The six essential nutrients
carbs proteins lipids mineral vitamins water
Carbs, lipids, proteins and ____ are all digested by enzymatic hydrolysis which is the decomposition run by inserting water.
nucleic acids
During carb digestion the breakdown of starch into individual ______ occurs.
glucose molecules
During carb digestion the breakdown of disaccharides into individual ______ occurs.
monosaccharides
Carbohydrate digestion begins in the oral cavity due to ______.
salivary amylase
In the oral cavity _____ between glucose molecules within starch occurs.
breaks in chemical bonds
Salivary amylase is inactivated by ______ of the stomach when bolus is swallowed (15-20 minutes after the bolus enters).
low pH of stomach
_______ continues digestion of starch into shorter strands of glucose (5-25 long), maltose and individual glucose molecules in the _______ during carbohydrate digestion.
pancreatic amylase
small intestines
Completion of digestion of carbs is accomplished by _______.
brush border enzymes in the small intestines
______ and ______ break bonds between glucose subunits.
dextrinase and glucoamylase
____ breaks bonds in maltose.
maltase
____ digests sucrose.
sucrase
____ digests lactose.
lactase
Monosaccharides are absorbed across _____ into blood..
epithelial lining
Blood transported through hepatic portal vein to liver where fructose and lactose are converted into _____.
glucose
Glucose can become part of _____.
blood glucose
Glucose can be taken up by ____ to oxidized through cellular respiration.
any cell
Glucose can be taken up by liver and muscle cells and synthesized into _____
glycogen and stored
Glucose can be converted into ____ and stored in adipose tissue.
fat (triglycerides)
During protein digestion there is a release of individual _____ to be absorbed into the blood and then transported to cells for synthesis of new proteins.
amino acids
Pepsinogen is released by chief cells and then activated by HCl released by the parietal cells to _____ in the stomach.
form pepsin
____ begins protein digestion while acidic environment denatures proteins.
pepsin
Pepsin doesn’t work in ____ due to high pH levels.
small intestines
The inactive forms of enzymes needed for protein digestion are released from the _____.
pancreas
_________ are enzymes produced by small intestines needed for activation of other enzymes.
Enteropeptidase
trypsinogen —– trypsin
chymotripsinogen —-chymostrypsin
procarboxypeptidase —-carboxypeptidase
Brush border enzymes
dipeptidase
aminopeptidase
_____ breaks down dipeptides during protein digestion.
dipeptidase
_____ breaks single amino acids from the amine end of the peptide.
aminopeptidase
Free ____ are absorbed across the epithelial lining into blood.
amino acids
Triglycerides are composed of glycerol molecule and ______.
three fatty acids
Enzymes needed for breaking bonds between ______ and _____.
fatty acids and glycerol
______ doesn’t need to be digested before absorption.
cholesterol
______ is a component of saliva, but not activated until reaches stomach for optimal pH level.
lingual lipase
______ is secreted by chief cells 30% of triglycerides are digested to diglycerides and a fatty acid.
gastric lipase
Pancreatic lipase digests majority of triglycerides, but needs ____ for this.
bile
Bile salts (part of bile) mechanically separate larger lipid droplets into smaller lipid droplets and its called ______.
emulsification
Bile salts contain polar and non polar sides which aid them in surrounding smaller fat droplets forming ______.
micelles
Smaller fat droplets allow greater access of pancreatic lipase to more effectively chemically digest the _____.
fat molecules
Cholesterols are also formed into _____m
micelles
No brush border enzymes are needed in ____ digestion
lipid
The _____ absorbs bile salts back into blood to be recycled.
ileum
Micelles transport lipids to ______ lining of the small intestines.
simple columnar
Lipids enter epithelial cells leaving bile salts within the ______ of the small intestines.
lumen
Fatty acids reattached to monoglycerides to _____.
reform triglycerides.
LIpids wrapped in protein to form a _____.
chylomicron
Golgi apparatus packages chylomicron in vesicle for _______ during lipid absorption.
exocytosis
_____ enter lacteals because they are to big to enter ______.
chylomicrons
blood capillaries
Nucleic acid digestion is not essential nutrient but still digested by specific enzymes in _____.
GI tract
Two types of nucleic acid: _____ and _____.
DNA and RNA
Nucleic acids are composed of sugar (ribose or deoxyribose), phosphate group, and ______,
nitrogenous base
Nucleases synthesized/released by pancreas break ____ between nucleotides.
phosphodiester bonds
Brush border enzymes involved in nuclei acid digestion include _____ and _____.
phophatase and nucleosidase
______ breaks bone holding phosphate
phosphatase
_______ breaks bonds between sugar and base (releasing sugar)
nucleosidase
During nuclei acid digestion all components absorbed across epithelium and ______.
into the blood.
What is the difference between mechanical and chemical digestion?
Mechanical digestion is physically breaking the food into small pieces
Chemical digestion is breaking the chemical bonds by enzyme
In which layers of the GI tract wall would you find MALT?
lamina propria and the submucosa
Between which two layers would you find the submucosal nerve plexus?
muscularis mucosa and submucosal
What is peristalsis? And how does it compare to mixing?
peristalsis is the movement of food through he GI tract while mixing doesn’t move the food but mechanically digests it
Retroperitoneal means _______ the peritoneum while intraperiotoneal means ______ the peritoneum.
behing
within
What are long/short reflexes?
long reflexes are signals received from the ANS within the medulla
Short reflexes are signals received from the enteric nervous system within the GI tract wall
During which phase of deglutition does the physical swallowing of a bolus from oral cavity to esophagus occur?
pharyngeal
Why is the most superior portion of the esophagus made with skeletal muscle while the most inferior portion is made with smooth muscle?
the superior portion is made with skeletal muscle to propel the food out of the pharynx faster, to allow for another inhalation/exhalation.
The inferior portion is made with smooth muscle because it is continuous with the smooth muscle of the stomach
How do surface mucus cells and neck mucus cells compare in function?
surface mcuus cells secrete mucin and an alkaline substance, needed to protect inner lining of stomach
Mucus neck cells secrete much and an acid substance to aid
What is pernicious anemia?
a decreased erythrocyte production due to a vitamin B12 deficiency
What type of cell produced HCl? How is this done without damaging the cell?
Parietal cells release both H+ and CL- into the gastric gland where they combine to form HCl
Nervous and hormonal control of the stomach causes what?
A change in the force of contraction, but not the rate as well as gastric secretion releases
What triggers the cephalic reflex and what does the reflex cause?
thoughts, smells, sight or taste of food will rigger it and it will cause an increase in both gastric secretions and force of contractions
What does gastrin do that the cephalic and gastric reflexes do not
stimulate the contraction of the pyloric sphincter
What three structures within the SI increase surface area?
circular folds, villi, microvilli
Where in the SI would you find lacteals and what is their function?
within the lamina propria of the villi, absorb fat from the GI tract
What is the gastoileal reflex and what trigger it?
movement of gastric contents from ileum to decorum, it is stimulated by food entering the stomach
What is a cupful cell? and where would you find it within the liver?
a macrophage within the hepatic sinusoid capillaries
Where is bile made? stored? and what is its function?
made in the liver, stored in the gallbladder, aids in the emulsification (mechanical digestion) of fats
What is released from the pancreas to help neutralize the acidic nature of the chyme that enters the duodenum?
HC03-
What does the large intestines absorb?
water, electrolytes, vitamins B and K
Why do we have bacteria within our LI?
to aid in the breakdown of nutrients that made it to the LI as well as produce vitamin B and K
KNOW AND BE ABLE TO EXPLAIN THE 3 PHASES OF DEGLUTITION
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BE ABLE TO LIST THE FOUR MAJOR TYPES OF ENZYMES NEEDED FOR CHEMICAL DIGESTION AND WHAT THEY DIGEST
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BE ABLE TO LIST THE FOUR MAJOR TYPES OF ENZYMES NEEDED FOR CHEMICAL DIGESTION AND WHAT THEY DIGEST
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KNOW WHAT HAPPENS TO GLUCOSE AFTER IT ENTERS TEH BODY?
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KNOW THE 3 YPES OF FATTY ACIDS AND THEIR STRUCTURES, BE ABLE TO BIVE AN EXAMPLE OF EACH
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KNOW THE 4 PHASES OF ATP PRODUCTION AND WHERE GLUCOSE, TRIGLYCERIDES, AND AMINO ACIDS COULD ENTER THIS CYCLE
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