Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/152

Click to flip

152 Cards in this Set

  • Front
  • Back
Definition: taking food and water into the mouth
ingestion
Definition: chewing, mixing, and churning food
mechanical digestion
Definition: digestive enzymes breakdown food
chemical digestion
Definition: a muscular tube that winds through the body and is responsible for the digestion and absorption of food (oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, anus)
digestive/GI tract
Definition: organs that aid in the breakdown of foodstuffs (teeth tongue, gallbladder, salivary glands, liver, and pancreas)
accessory digestive organs
What are the three major functions of the tunics of the GI tract?
-secretion of mucus

-absorption of end products of digestion


-protection against infectious disease

What do the mucus secretions of tunics do?
-protect digestive organs from digesting themselves

-ease food along the tract

The stomach and small intestine mucosa contain what two things?
-enzyme secreting cells

-hormone-secreting cells

What are the 4 tunics of the digestive tract?
mucosa

submucosa


muscularis


serosa/adventitia

Definition: innermost layer that lines the lumen of the alimentary canal
mucosa
The mucosa layer consists of what three things?
mucous epithelium

lamina propria


muscularis mucosae

Definition: connective layer tissue containing the submucosal plexus, blood vessels, and small glands
submucosa
Definition: consists of an inner layer of circular smooth muscle and an outer layer of longitudinal smooth muscle
muscularis
The ______ is between the two muscle layers.
myenteric plexus
Definition: forms the outermost layer of the digestive tract
serosa/adventitia
Definition: consists of the nervous plexuses within the wall of the digestive tract
enteric nervous system
What are the two major plexuses of the enteric NS?
submucosal nerve plexus

myenteric nerve plexus

Definition: regulates glands and smooth muscle in the mucosa
submucosal nerve plexus
Definition: major nerve supple that control GI tract mobility
myenteric nerve plexus
Definition: an enteric neuron that detects changes in the chemical composition of the digestive tract
sensory neuron
Definition: an enteric neuron that stimulates or inhibits smooth muscle contraction and glandular secretion
motor neurons
Definition: an enteric neuron that connects sensory to motor neurons
interneurons
Nervous regulation involves local reflexes in the ____ and ____ reflexes.
ENS

CNS

Definition: a serous membrane that lines the abdominopelvic cavity and organs
peritoneum
Definition: peritoneum that extends from the body wall to many of the abdominopelvic organs
mesenteries
Definition: the space between the lips or cheeks and the alveolar processes, which contain the teeth
vestibule
Definition: lies medial to the alveolar processes
oral cavity proper
The withstand abrasions, the mouth is lined with _______.
stratified squamous epithelium
Definition: part of the roof of the mouth that assists the tongue in chewing
hard palate
Definition: part of the roof of the mouth that is a mobile fold mostly of skeletal muscle; contains the uvula and closes off the nasopharynx during swallowing
soft palate
What are the 3 functions of the tongue?
- gripping and repositioning food during chewing

-mixing food with saliva and forming the bolus


-initiation of swallowing and speech

Definition: secures the tongue to the floor of the mouth
frenulum
Definition: 20 teeth that erupt between 6-24 mos of age; replaced by 32 permanent teeth between 5-11 years of age
deciduous teeth
What are the 4 types of teeth?
incisors

canines


premolars


molars

Definition: exposed part of the tooth above the gingiva; dentin covered by enamel
crown
Definition: acellular material composed of calcium salts and hydroxyapatite crystals
enamel
Definition: portion of the tooth embedded in the jawbone; composed of dentin
root
Within the dentin of the root is the ______, which is filled with ____, _____, and ______.
pulp cavity

pulp


blood vessels


nerves

Definition: hold the teeth in the alveoli
periodontal ligaments
Definition: produce and secrete saliva
salivary glands
What are the functions of saliva?
-cleanses the mouth

-moistens and dissolves food chemicals


-aids in bolus formation


-contains enzymes that break down starch

What are the three pairs of salivary glands?
parotid

submandibular


sublingual

What are the two cells of the salivary glands and what do they produce?
serous: enzymes, ions, and mucin

mucous: produce mucous

Definition: 97-99.5% water and slightly acidic solution
saliva
What does saliva contain?
-electrolytes

-digestive enzyme: salivary amylase


-proteins: mucin, lysozyme, defensins, and IgA


-metabolic wastes: urea and uric acid

Salivation is controlled primarily by what?
parasympathetic system of the ANS
Salivation is triggered by what two things?
-ingested food which stimulates chemoreceptors and pressoreceptors

-the thought of food

Salivation is inhibited by what?
strong sympathetic stimulation
Definition: sphincters in the esophagus that regulate movement
upper and lower esophageal sphincters
Definition: a bolus of food is moved be the tongue from the oral cavity to the pharynx
voluntary phase of swallowing
Definition: a reflex caused by the stimulation of stretch receptors in the pharynx; the soft palate closes the nasopharynx; the epiglottis, vestibular folds, and vocal folds close the opening into the larynx; the pharyngeal muscles move the bolus into the esophagus
pharyngeal phase
Definition: a reflex initiated by the stimulation of stretch receptors in the esophagus; a wave of contraction moves the food into the stomach
esophageal phase
Definition: contraction to move food through the GI tract
peristalsis
Definition: temporary "storage tank" where chemical breakdown of proteins begins and food is converted from a bolus to chyme
stomach
Definition: opening from the stomach to the esophagus
gastroesophageal opening
Definition: opening from stomach to duodenum
pyloric orifice
What are the major regions of the stomach?
cardiac part

fundus


body


pyloric part (contains pyloric sphincter)

The lateral sides of the stomach consists of what?
the greater and lesser curvatures
The wall of the stomach consists of what 4 things?
external serosa

muscle layer (longitudinal, circular, and oblique)


submucosa


simple columnar epithelium

Definition: produce an alkaline mucous with bicarbonate, which coats and protect the stomach lining
surface mucous cells
Definition: folds of the mucosa and submucosa of the stomach
rugae
The ____ and ____ produce juice in the stomach.
gastric pits

gastric glands

Definition: gastic secretory cells that secretes acid mucus
mucous neck
Definition: gastic secretory cells that secretes HCl and intrinsic factor
parietal cells
Definition: gastric secretory cells that produce pepsinogen
chief cells
Pesinogen is activated to _____ by ________ and _______.
pepsin

HCl in the stomach


pepsin (positive feedback)

Definition: gastric secretory cells that produce regulatory hormones (gastrin, histamine, endorphins, serotonin, CCK, and somatostatin into the lamina propria)
endocrine cells
Definition: ingested food mixed with gastric juice
chyme
____ protects the lining of the stomach. _____ digests proteins. ___ promotes pepsin activity and kills microorganisms. ______ is necessary for vitamin B12 absorption. _____ and ____ regulate stomach secretions.
mucus

pepsin


HCl


intrinsic factor


gastrin


histamine

A _____ moves H+ out of parietal cells in exchange for K+.
proton pump
Definition: initiated by sight, smell, taste, or thought of food; nerve impulses from the medulla stimulate HCl, pepsinogen, gastrin, and histamine secretion
cephalic phase of stomach secretion
Definition: initiated by distention of the stomach, which stimulates gastrin secretion ad activates CNS and local reflexes that promote secretion
gastric phase of stomach secretion
Definition: acidic chyme enters the duodenum and stimulates neuronal reflexes and the secretion of hormones (secretin and CCK) that inhibit gastric secretions
gastrointestinal phase of stomach secretion
_____ mix the stomach contents with stomach secretions to form ____. ________ move the chyme into the duodenum.
waves

chyme


peristaltic waves

Definition: vomiting
reverse peristalsis
Definition: the body's major digestive organ where digestion is completed and absorption occurs; runs from the pyloric sphincter to the ileocecal valve
small intestine
What are the three subdivisions of the small intestine?
duodenum

jejunum


ileum

Where do the bile and pancreatic ducts empty?
duodenum
Definition: deep folds of the mucosa and submucosa in the small intestine
circular folds
Definition: fingerlike extensions of the mucosa in the small intestine
villi
Definition: tiny projection of absorptive mucosal cells' plasma membranes in the small intestine; forms the brush border
microvilli
The epithelium of the mucosa in the small intestine is _______.
columnar epithelium
Definition: pits between the villi in the mucosa of the small intestine
intestinal glands
Definition: cells found in the mucosa of the small intestine that produce digestive enzymes
absorptive cells
Definition: cells found in the mucosa of the small intestine that produce a protective mucus
goblet cells
Definition: cells found in the mucosa of the small intestine that protect the intestinal epithelium from bacteria
granular cells (Paneth cells)
Definition: cells found in the mucosa of the small intestine that produce regulatory hormones
endocrine cells
Definition: aggregated lymphoid follicles found in the submucosa of the small intestine
Peyer's patches
The _____ protects the small intestine against digestive enzymes and gastric acids. Digestive enzymes (_______ and _______) are bound to the ______.
mucus

disaccharidases


peptidases


intestinal wall

What 3 things stimulate intestinal secretion?
chemical or tactile stimulation

vagal stimulation


secretin

_____ contraction mix intestinal contents. _______ contractions move materials distally.
segmental

peristaltic

What 3 things stimulate contractions in the small intestine?
distension of the intestinal wall

local reflexes


PNS

What stimulates the contraction of the ileocecal sphincter?
distension of the cecum
What are the 4 lobes of the liver?
right

left


caudate


quadate

_______ liver lobules are the structural and functional units of the liver.
hexagonal-shaped
Definition: composed of hepatocyte (liver cell)plates radiating outward from a central vein
lobules
_________ are found at each of thesix corners of each liver lobule
portal triads
Definition: conduct bile toward the duodenum
hepatic duct
Definition: supplies oxygen-rich blood to theliver
hepatic artery
Definition: carries venous blood with nutrientsfrom digestive viscera
hepatic portal vein
The portal triad consists of what 3 things?
hepatic duct

hepatic artery


hepatic portal vein

The_____ are composed of columns of hepatocytes separated by the _______. _______ are enlarged spaces filled with blood and lined with endothelium and hepaticphagocytic cells.
hepatic cords

bile canaliculi


sinusoids

Definition: hepatic macrophages found in liversinusoids
Kupffer cells
What are the 4 functions of the liver?
-produces bile

-stores and processes nutrients, produces new molecules, and detoxifies


-hepatic phagocytic cells phagocytize red blood cells, bacteria, and other debris


-produces blood components

What is the functions of bile?
contains bile salts that emulsify fat
Branchesof the hepatic artery and the hepatic portal vein in the portal triads emptyinto ____, which empty into _____, which join to form the ____, whichleave the liver.
hepatic sinusoids

central veins


hepatic veins

_____ collect bile from hepatocytes and jointhe _____ inthe portal triads. These converge to form the right and left hepatic ducts,which exit the liver. Theleft and right hepatic ducts join to form the _____. The ____ fromthe gallbladder joins the common hepatic duct to form the ____. This and pancreatic duct join at the ____, which opens into the duodenum at the_____.
bile canaliculi

small hepatic ducts


common hepatic duct


cystic duct


common bile duct


hepatopancreatic ampulla


major duodenal papilla



Definition: a small sac on the inferior surfaceof the liver; stores and concentrates bile
gallbladder
Definition: a yellow-green, alkaline solutioncontaining bile salts, bile pigments, cholesterol, neutral fats, phospholipids,and electrolytes
bile
Bile salts are ____ derivatives that: ______, facilitate fat and cholesterolabsorption, and helps make ______.
cholesterol

emulsify fat


cholesterol soluble

_____ recycles bile saltstherefore they are never voided in the feces.
enterohepatic circulation
The chief bile pigment is______, a waste product of _____. It is metabolized bybacteria in the small intestines and _____ is produced, which gives feces its darkcolor.
bilirubin

heme


urobilogen

Acidic,fatty chyme causes the duodenum to release _____ and _____ into the bloodstream.
Cholecystokinin (CCK)

secretin

Cholecystokinin causes: the gallbladder to contract and______, relaxation of the ______ of thebile duct and hepatopancreatic ampulla. Secretin _____ (water and bicarbonate ions). As a result, bile enters theduodenum.
release bile

sphincters


increases bile secretion

_____ causes weak contractions of the gallbladder.
vagal stimulation
Definition: secretes pancreatic juice whichbreaks down all categories of foodstuff
pancreas
Definition: clusters of secretory cells thatcontain zymogen granules with digestive enzymes; connect to a duct system thateventually forms the pancreatic duct
acini
The pancreatic duct joins the _____. The accessory pancreaticduct empties into the duodenum at the _____.
hepatopancreatic ampulla

minor duodenal papilla

Thepancreas also has an endocrinefunction. Theislets of Langerhans release of ____ and ____.
insulin

glucagon



Theaqueouscomponent ofpancreatic juice is produced by the ____ and contains_____. Its a water solution of enzymes andelectrolytes (primarily HCO3–). It ______ acidic chyme and provides ______ forpancreatic enzymes.
small pancreatic ducts

bicarbonate ions


neutralizes


optimal environment



Theenzymaticcomponent ofpancreatic juice is produced by the ____ and contains enzymes that digestcarbohydrates, lipids, and proteins. Enzymes are released in _____ andactivated in the ______.
acini

inactive form


duodenum



_______ stimulates the release of the aqueous component, which neutralizes acidic chyme. ______ stimulates the secretion of the enzymatic component and relaxation of thesphincters of the pancreatic duct and hepatopancreatic ampulla. ____ increases and ____ decreases secretion ofenzymes.
secretin

cholecystokinin


parasympathetic stimulation


sympathetic stimulation



The large intestine extendsfrom the _____ to the ____. It absorbs ____ and eliminate the waste via _____. It issubdivided into the ____, _____, ____, _____, and _____.
ileocecal valve

anus


water


feces


cecum


appendix


colon


rectum


anal canal



The _____ forms a blind sac at the junctionof the small and large intestines. The ____ is a blindtube off the cecum.
cecum

vermiform appendix

The colon has distinctregions: _____, _____, _____, and _______. The sigmoid colon joins the _____. The _____, the last segment ofthe large intestine, opens to the exterior at the anus. The anal canal contains two______ to allow the movement of feces.
ascending colon

transverse colon


descending colon


sigmoid colon


rectum


anal canal


sphincters

Definition: three bands of longitudinal smooth muscle in its muscularis
teniae coli
What are 3 unique features of the large intestine?
-teniae coli

-huastra


-epiploic appendages

Definition: pocketlike sacs caused by the tone of the teniae coli
haustra
Definition: fat-filled pouches of visceralperitoneum
epiploic appendages
Themucosal lining of the large intestine is ____ withmucus-producing _____.
simple columnar epithelium

crypts

The bacteria in the large intestine do what 5 things?
–Colonize the colon

–Ferment indigestible carbohydrates


–Release irritating acids and gases(flatus)


–Synthesize B complex vitamins andvitamin K


–Constitute about 30% of the dryweight of the feces

_____ mix the contents and moves them slowlytoward the anus. Massmovements are strong peristaltic contractions that occur three or four times aday.
Haustra
Definition: elimination of feces
defecation
Distension of rectal walls causedby feces: stimulates contraction of the_____ and relaxes the _____. ______ moves feces throughthe sphincter. Voluntary activity regulatesmovement through the ______.
rectal walls

internal anal sphincter


reflex activity


external anal sphincter




Definition: thebreakdown of organic molecules into their component parts
digestion
Definition: thebreaking of covalent chemical bonds in organic molecules by digestive enzymes
chemical digestion
Definition: uptakeof digestive tract contents
absorption
Definition: thedistribution of nutrients throughout the body
transport
Carbohydrate digestion begins in the ____ with _____ digesting starches. _____ finishes theprocess in the _____. Simplesugars are also broken down here.
mouth

salivary amylase


pancreatic amylase


small intestine


Protein digestion: protein is broken down into amino acids. It begins in the _____ with _____. _____ and ______ are alsoimportant protein digesting enzymes.
amino acids

stomach


pepsin


trypsin


chymotrypsin

In lipid digestion,the ______ is the sole source oflipid digestion by _____. Lipids enter ______ and are transported tosystemic circulation via _____.
small intestine

lipases


lacteals


lymph

Nucleic acids are broken down by _____ inthe _____.
pancreatic nucleases

small intestine

In carbohydrate digestion, ____ are broken down into ____ by a number of different enzyme. These are then taken up by ____ via ____ that is powered by a Na+ gradient or by facilitateddiffusion. They are carried to the ____, where thenon-glucose sugars are converted to glucose. Glucose is transported to the cellsthat require energy.
polysaccharides

monosaccharides


intestinal epithelial cells


symport


liver



Glucose enters the cells through ____. ____ influences the rate of glucose transport.

facilitated diffusion

insulin
Definition: the transformation of large lipid droplets into smaller droplets and isaccomplished by bile salts
emulsification
_____ digests lipid molecules to form ____ and a _____. ______ form around lipid digestion products and move to epithelial cells of the _____, where the products pass into the cells via _____. Withinthe epithelial cells, free fatty acids are combined with ____ to form ____.
lipase

fatty acids


monoglyceride


micelles


small intestine


simple diffusion


monoglycerides


triglycerides





______ coat triglycerides, phospholipids, and cholesterol to form ______. These enter _____ within intestinal villi and are carried through the lymphatic system to the bloodstream. Triglycerides are stored in _____, converted into other molecules, or used as energy.
proteins

chylomicrons


lacteals


adipose tissue

LDLare taken into cells by _____, which is controlled by anegative-feedback mechanism.
receptor-mediated endocytosis
____ transports cholesterol to cells, and ____ transports it from cells to the liver.
LDL

HDL




____ in the stomach breaks proteins into smaller polypeptide chains. ____ from the pancreas produce smallpeptide chains. _____,bound to the microvilli of the small intestine, break down peptides. Tripeptides, dipeptides, and amino acids areabsorbed by ____ that is powered by a Na gradient. Aminoacids are transported to the ___, where the amino acids can be modified orreleased into the bloodstream. Aminoacids are actively transported into cells under the stimulation of _____ and _____. Amino acids are used as building blocksor for ____.
pepsin

proteolytic enzymes


peptidases


symport


liver


growth hormone


insulin


energy







About __ liters of water enters thedigestive tract each day. It can move in either direction acrossthe wall of the small intestine, depending on the _______ across theepithelium. Epithelial cells actively transport__, ___, __, and ___ fromthe intestine. _____ move passivelythrough the wall of the duodenum and jejunum but are actively transported fromthe _____.
9

osmotic gradients


Na


K


Ca+2


Mg+2


chloride ions


ileum




Themucous layer, the connective tissue, the muscles, and the secretions all tendto _____ as a person ages. Thesechanges make an older person more open to _____ and _______.
decrease

infections


toxic agents