Digestive System Flashcards
includes the digestive tract and its accessory organs, which process food into molecules that can be absorbed and utilized by the cells of the body.
digestive system
includes the digestive tract and its accessory organs, which process food into molecules that can be absorbed and utilized by the cells of the body.
digestive system
is broken down, bit by bit, until the molecules are small enough to be absorbed and the waste products are eliminated
foodd
digestive tract is also called the
alimentary canal or GI tract
consists of a long continuous tube that extends from the mouth to the anus.
digestive tract
are accessory structures located in the mouth.
tongue teeth
major accessory organs that have a role in digestion.
liver
gallbladder
pancreas
Food undergoes three types of processes in the body:
digestion
absorption
elimination
processes that occur in the digestive tract
digestion
absorption
After the nutrients are absorbed, they are available to all cells in the body and are utilized by the body cells in
metabolism
prepares nutrients for utilization by body cells through six activities, or functions.
digestive system
The first activity of the digestive system is to take in food through the mouth. This process, called
ingestion
begins in the mouth with chewing or mastication and continues with churning and mixing actions in the stomach.
mechanical digestion
The complex molecules of carbohydrates, proteins, and fats are transformed by chemical digestion into smaller molecules that can be absorbed and utilized by the cells.
chemical digestion
uses water and digestive enzymes to break down the complex molecules.
hydrolysis
speed up the hydrolysis process, which is otherwise very slow.
digestive enzymes
Mixing movements occur in the stomach as a result of
smooth muscle contraction
The movements that propel the food particles through the digestive tract are called
peristalsis
rhythmic waves of contractions that move the food particles through the various regions in which mechanical and chemical digestion takes place.
peristalsis
The simple molecules that result from chemical digestion pass through cell membranes of the lining in the small intestine into the blood or lymph capillaries. This process is called
absorption
The removal of indigestible wastes through the anus, in the form of feces is
defecation
digestive tract is how long
9 meters in length
The wall of the digestive tract has four layers or tunics:
mucosa
submucosa
muscular layer
serous layer or serosa
the innermost tunic of the wall. It lines the lumen of the digestive tract.
mucosa or mucous membrane layer
The mucosa consists of epithelium, an underlying loose connective tissue layer called
lamina propria
thin layer of smooth muscle in the mucosa called the
muscularis mucosa
In certain regions, the mucosa develops folds that increase the
surface area
. Ducts from other glands pass through the mucosa to the
lumen
In the mouth and anus, where thickness for protection against abrasion is needed, the epithelium is ___
stratified squamous epithelium
The stomach and intestines have a thin ____ for secretion and absorption
what kind of tissue
simple columnar epithelial layer
is a thick layer of loose connective tissue that surrounds the mucosa
submucosa
This layer also contains blood vessels, lymphatic vessels, and nerves. Glands may be embedded in this layer.
submucosa
The smooth muscle responsible for movements of the digestive tract is arranged in two layers
inner circular layer
outer longitudinal layer
is between the two muscle layers in the digestive tract
myenteric plexus
principally responsible for the peristaltic movement of the bowels.
myenteric plexus
Above the diaphragm, the outermost layer of the digestive tract is a connective tissue called
adventitia
Below the diaphragm, the connective tissue is called
serosa
is a tube running from mouth to anus.
digestive system
chief goal is to break down huge macromolecules (proteins, fats and starch), which cannot be absorbed intact,
digestive system
that can be absorbed across the wall of the tube, and into the ___ for dissemination throughout the body
circulatory system
Regions of the digestive system can be divided into two main parts:
alimentary tract
accessory organ
The alimentary tract of the digestive system is composed of the
mouth
pharynx
esophagus
stomach
small and large intestine
rectum
anus
Associated with the alimentary tract are the following accessory organs
salivary glands
liver
gallbladder
pancreas
is the first part of the digestive tract. It is adapted to receive food by ingestion, break it into small particles by mastication, and mix it with saliva.
mouth or oral cavity
The lips, cheeks, and palate form the boundaries.
mouth
contains the teeth and tongue and receives the secretions from the salivary glands.
oral cavity
help hold food in the mouth and keep it in place for chewing.
lips and cheeks
used in the formation of words for speech.
lips and cheek
numerous sensory receptors that are useful for judging the temperature and texture of foods.
lips
is the roof of the oral cavity.
palate
separates the oral cavity from the nasal cavity.
palate
The anterior portion supported by bone
hard palate
posterior portion of palate, a skeletal muscle and connective tissue
soft palate
Posteriorly, the soft palate ends in a projection called the
uvula
During swallowing, the soft palate and uvula move upward to direct food away from the nasal cavity and into the
oropharynx
manipulates food in the mouth and is used in speech.
tongue
covered with papillae that provide friction and contain the taste buds.
tongue
A complete set of deciduous (primary) teeth contains ___ teeth
20 teeth
There are __ teeth in a complete permanent (secondary) set.
32 teeth
he shape of each tooth type corresponds to the way it handles ___
food
Food is forced into the pharynx by the
tongue
When food reaches the opening, sensory receptors around the fauces respond and initiate an
involuntary swallowing reflex
involuntary swallowing reflex has several parts
(1) The uvula is elevated to prevent food from entering the nasopharynx.
(2) he epiglottis drops downward to prevent food from entering the larynx and trachea in order to direct the food into the esophagus.
(3) Peristaltic movements propel the food from the pharynx into the esophagus.
is a collapsible muscular tube that serves as a passageway between the pharynx and stomach
esophagus
it is posterior to the trachea and anterior to the vertebral column
esophagus
it passes through an opening in the diaphragm, called the
esophageal hiatus
has glands that secrete mucus to keep the lining moist and well lubricated to ease the passage of food
mucosa
control the movement of food into and out of the esophagus
upper and lower esophageal sphincter
The lower esophageal sphincter is sometimes called the
cardiac sphincter
resides at the esophagogastric junction
what sphincter
lower esophageal sphincter
which receives food from the esophagus, is located in the upper left quadrant of the abdomen.
stomach
The stomach is divided into the
fundic
cardiac
body
pyloric end
lesser curvature is located on the ___
right side
greater curvature on the __ side
left
The mucosal lining of the stomach is what kind of tissue
simple columnar epithelium with numerous tubular gastric glands
The gastric glands open to the surface of the mucosa through tiny holes called
gastric pits
Four different types of cells make up the gastric glands:
mucous cells
parietal cells
chief cells
endocrine cells
The secretions of the exocrine gastric glands - composed of the mucous, parietal, and chief cells - make up the
gastric juice
The products of the _____ cells are secreted directly into the bloodstream and are not a part of the gastric juice
endocrine
The endocrine cells secrete the hormone ___ which functions in the regulation of gastric activity.
gastrin
The regulation of gastric secretion is accomplished through what kind of mechanism
neural and hormonal mechanism
is produced all the time but the amount varies subject to the regulatory factors.
gastric juice
Regulation of gastric secretions may be divided into what phases
cephalic
gastric
intestine
houghts and smells of food start what phase
cephalic
the presence of food in the stomach initiates the ___ phase
gastric phase
and the presence of acid chyme in the small intestine begins the
intestinal phase
Relaxation of the pyloric sphincter allows chyme to pass from the stomach into the
small intestine
The rate of which this occurs depends on the nature of the chyme and the receptivity of the small intestine.
stomach emptying
extends from the pyloric sphincter to the ileocecal valve, where it empties into the large intestine.
small intestine
he small intestine finishes the process of absorbs the nutrients, and passes the residue on to the large intestine.
digestion
are accessory organs of the digestive system that are closely associated with the small intestine.
liver
gallbladder
pancreas
The small intestine is divided into the
duodenum
jejunum
ileum
The absorptive surface area of the small intestine is increased by
plicae cirulares
villi
microvilli
cells in the mucosa of the small intestine secrete mucus, peptidase, sucrase, maltase, lactase, lipase, and enterokinase.
exocrine cell
cells secrete cholecystokinin and secretin.
endocrine cells
The most important factor for regulating secretions in the small intestine is the presence of
chyme
largely a local reflex action in response to chemical and mechanical irritation from the chyme and in response to distention of the intestinal wall.
regulating secretion
This is a direct reflex action, thus the greater the amount of chyme, the greater the ___
secretion
is larger in diameter than the small intestine.
large intestine
It begins at the ileocecal junction, where the ileum enters the large intestine, and ends at the anus.
large intestine
consists of the colon, rectum, and anal canal.
large intestine
has a large number of goblet cells but does not have any villi in the large intestine
mucosa
The longitudinal muscle layer, although present, is ___ in the large intestine
incomplete
The longitudinal muscle is limited to three distinct bands, called that run the entire length of the colon
teniae coli
Contraction of the teniae coli exerts pressure on the wall and creates a series of pouches,
haustra
, pieces of fat-filled connective tissue that are attached to the outer surface of the colon.
epiploic appendages
Unlike the small intestine, the ___ intestine produces no digestive enzymes
large
completed in the small intestine before the chyme reaches the large intestine.
chemical digestion
Functions of the large intestine include the
absorption of water and electrolytes
elimination of feces
continues from the sigmoid colon to the anal canal and has a thick muscular layer.
rectum
rectum follows the curvature of
sacrum
It follows the curvature of the sacrum and is firmly attached to it by ___ tissue
connective
ends about 5 cm below the tip of the coccyx, at the beginning of the anal canal.
rectum
The last 2 to 3 cm of the digestive tract is the
anal canal
continues from the rectum and opens to the outside at the anus.
anal canal
The mucosa of the rectum is folded to form longitudinal
anal columns
the smooth muscle layer in anal canal is thick and forms the
internal anal sphincter
sphincter is under involuntary control
internal anal sphincter
located at the inferior end of the anal canal.
external anal sphincter
This sphincter is composed of skeletal muscle and is under voluntary control.
external anal sphincter
The salivary glands, liver, gallbladder, and pancreas are not part of the digestive tract, but they have a role in digestive activities and are considered
accessory organs
Three pairs of major salivary glands
parotid
submandibular
sublingual
numerous smaller ones secrete saliva into the oral cavity, where it is mixed with food during mastication.
salivary glands
contains water, mucus, and enzyme amylase.
saliva
functions of saliva
=It has a cleansing action on the teeth.
=It moistens and lubricates food during mastication and swallowing.
-It dissolves certain molecules so that food can be tasted.
=It begins the chemical digestion of starches through the action of amylase, which breaks down polysaccharides into disaccharides.
s located primarily in the right hypochondriac and epigastric regions of the abdomen, just beneath the diaphragm.
liver
largest gland in the body
liver
On the surface, the liver is divided into
2 major lobes
2 smaller lobes
he functional units of the liver are
lobules with sinusoids
that carry blood from the periphery to the central vein of the lobule.
lobules with sinusoids
Freshly oxygenated blood is brought to the liver by the
common hepatic artery
branch of the celiac trunk from the abdominal aorta.
common hepatic artery
Blood that is rich in nutrients from the digestive tract is carried to the liver by the
hepatic portal vein
perform most of the functions attributed to the liver
hepatocytes
line the sinusoids are responsible for cleansing the blood in the liver
kupffer cells
Liver functions include the following:
-secretion
-synthesis of bile salts
-synthesis of plasma protein
-storage
-detoxification
-excretion
-carbohyrate metabolism
-lipid metabolism
-protein metabolism
-filtering
is a pear-shaped sac that is attached to the visceral surface of the liver by the cystic duct.
gallbladder
erve as a storage reservoir for bile.
gallbladder
is a yellowish-green fluid produced by liver cells.
bile
main components are are water, bile salts, bile pigments, and cholesterol.
bile
act as emulsifying agents in the digestion and absorption of fats.
bile salts
Cholesterol and bile pigments from the breakdown of ____ are exerted from the body in the bile
hemoglobin
has both endocrine and exocrine functions.
pancreas
portion of pancreas that consist of the scattered islets of Langerhans,
endocrine
which secrete the hormones insulin and glucagon into the blood.
islets of langerhans
portion is the major part of the gland
exocrine
consists of pancreatic acinar cells that secrete digestive enzymes into tiny ducts interwoven between the cells
what portion of pancreas
exocrine portion
secrete digestive enzymes into tiny ducts interwoven between the cells.
acinar cells
include anylase, trypsin, peptidase, and lipase.
pancreatic enzymes
Pancreatic secretions are controlled by the hormones
secretin
cholecystokinin
term for eating
ingestion
release of water, enzymes, buffers
secretion
breakdown of foods
digestion
breakdown of foods by movements of digestive organs
mechanical digestion
breakdown of foods by enzymes
chemical digestion
moving products of digestion into the body
absorption
dumping waste products
defecation
A tube through which foods pass and where digestion and absorption occur
gastrointestinal tract
Includes: mouth, pharynx, esophagus, stomach, small intestine, large intestine
GI tract
Organs that help in digestion but through which food never passes.
accessory organs
Includes: teeth, tongue, salivary glands, liver, gallbladder, and pancreas
accessory organs
four layers of GI tract
mucosa
submucosa
muscularis
serosa
epithelium in direct content with food; made of connective tissue, glands, and thin muscularis mucosae
what layer
mucosa
connective tissue, blood vessels, lymphatic vessels, and enteric nervous system (ENS)
what layer
submucosa
inner circular layer, outer longitudinal layer
what layer
muscularis
what muscle in most of GI tract
smooth muscle
muscle in mouth, pharynx, upper esophagus, and external anal sphincter
skeletal muscle
visceral layer of peritoneum
what layer
serosa
Also forms extensions: greater omentum and mesentery
serosa
a 4-layered fold of peritoneum that extends down from the stomach, covering much of the colon and small bowel.
greater omentum
a fold of membrane that attaches the intestine to the wall around the stomach area and holds it in place
mesentery
Formed by Cheeks and tongue
Hard palate anteriorly, soft palate posteriorly
mouth
what palate is located anteriorly
hard palate
what palate is located posteriorly
soft palate
U-shaped extension of soft palate posteriorly
uvula
During swallowing, this blocks entry of food or drink into nasal cavity
uvula
muscular accessory organ
tongue
❑Maneuvers food for chewing
❑Adjusts shape for speech and swallowing
tongue
located at base of tongue
lingual tonsils
Exocrine glands with ducts that empty into oral cavity
salivary glands
three pairs of salivary glands
parotid
submandibular
sublingual
Largest; inferior and anterior to ears
what salivary gland
parotid
In floor of mouth; medial and inferior to mandible
what salivary glands
submandibular
Inferior to tongue and superior to submandibular
what salivary gland
sublingual
99.5% water, salivary amylase, mucus and other solutes
saliva
Dissolves food and starts digestion of starches
saliva
Accessory organs in bony sockets of mandible and maxilla
teeth
three external regions of the teeth
crown
root
neck
region of teeth above gums
crown
region of teeth embedded in socket
root
region of teeth between crown and root near gum line
neck
Three layers of material in teeth
enamel
dentin
pulp
hardest substance in body; over crown
enamel
majority of interior of tooth
dentin
nerve, blood vessel, and lymphatics in teeth
pulp cavity
Humans have __ sets of teeth
two
teeth that are replaced by the permanent teeth between ages 6 and 12 years.
deciduous teeth
how many deciduous teeth are there
20
teeth appear between 6 years and adulthood
permanent
how many permanent teeth are there
32
Four types of teeth
incisors
cuspids
premolars
molars
how many incisors
8
used to cut food
incisors
used to tear food
cuspds/canines
how many cuspids are there
4
for crushing and grinding food
what kind of teeth
premolars
how many premolars
8
used for crushing and grinding food
molars
how many molars
12
❑Chewing mixes food with saliva
❑Rounds up food into a soft bolus for swallowing
what kind of digestion
mechanical digestion
enzyme that aids in chemical digestion
salivary amylase
breaks down polysaccharides (starch)
salivary amylase
starch broken down by salivary amylase into
maltose and larger fragments
Continues in the stomach for about an hour until acid inactivates amylase
chemical digestion
3 stages of swallowing
voluntary
pharyngeal
esophageal
stage of swallowing wherein bolus of food > oropharynx
voluntary
stage of swallowing in oropharynx > esophagus
pharyngeal stage
Soft palate moves up and epiglottis moves down; prevent food from entering nasopharynx and larynx
what stage
pharyngeal stage
stage of swallowing where food → stomach by peristalsis
esophageal
esophageal sphincters are divided into two
upper
lower
esophageal sphincter that controls entry → esophagus
upper
esophageal sphincter that controls → stomach; GERD affects
lower
occurs when stomach acid repeatedly flows back into the tube connecting your mouth and stomach (esophagus).
GERD (gastroesophageal reflux disease)
J- shaped enlargement of GI tract
stomach
◼Mixing chamber and holding reservoir
◼Very elastic/expandable and muscular
stomach
Four regions of stomach
cardia
fundus
body
pylorus
surrounds upper opening
what stomach region
cardia
superior and to left of cardia
what region of stomach
fundus
large central portion
what kind of stomach region
body
lower part leading to pyloric sphincter and duodenum
what region of stomach
pylorus
stomach layers (4)
mucosa
secretary cells
muscularis
serous membrane
Empty stomach lies in folds called
rugae
what kind of tissue in the stomach
simple columnar epithelium
glands in the stomach secrete
mucus
line gastric pits in the stomach
gastric glands
secretory cells in the stomach that secrete mucous
mucous cells
secretory cells in the stomach that secrete HCl and intrinsic factor
parietal cells
HCl and intrinsic factor, these secretions collectively called
gastric juice
helps with vitamin B12 absorption needed for RBC formation.
intrinsic factor
if intrinsic factor is missing results in
anemia
secrete inactive enzyme pepsinogen
chief cells
secrete gastrin (hormone) into blood
g cells
a peptide hormone primarily responsible for enhancing gastric mucosal growth, gastric motility, and secretion of hydrochloric acid (HCl) into the stomach
gastrin
Three layers of muscularis in stomach
outer
middle
inner
layer of stomach muscularis that is longitudinal
outer
layer of stomach that is circular
middle
layer of stomach muscularis that is oblique (extra layer not in other organs) provides for efficient gastric contractions
inner
covers organising stomach
visceral perotineum
Extensions of serosa (2)
greater omentum
mesentery
hangs from curve of stomach (serosa)
greater omentum
attaches small intestine to posterior wall of abdomen and provides route for vessels
what kind of serosa
mesentery
◼Stretching of stomach wall → nerve impulses →
◼Secretion + mixing waves →
◼Food mixed with juice → now called chyme
mechanical digestion
food mixed with gastric juice is called
chyme
digests protein
pepsin
pepsin is made out of
pepsinogen + HCl
small chains of amino acids
peptides
through pyloric sphincter
gastric emptying
what is emptied fastest to slowst
carbs
fats
proteins
carbs
proteins
fats
once in ____ > feedback inhibition of stomach
duodenum
water, ions, some drugs is what in the stomach
little absorption
Location: behind stomach
pancreas
❑Produces pancreatic juice in acinar cells
❑Passes into duodenum via pancreatic duct
pancreas
Secretions that help digestion (sodium bicarbonate)
pancreas
pH of sodium bicarbonate
pH 7.1-8.2
digestive enzymes in pancreas (3)
pancreatic lipase
pancreatic amylase
proteases
fat-digesting enzyme in pancreas
pancreatic lipase
starch-digesting pancreatic enzyme
pancreatic amylase
pancreatic enzyme made in inactivated form
proteases
proteases is activated by what from small intestine
enterokinase
Chymotrypsinogen, trypsinogen, carboxypeptidase
RNAase and DNAase
what enzyme
proteases
Weighs 1.4 kg (3 lb): 2nd largest organ in the body; large right lobe + 3 smaller parts
liver and gallbladder
located in what quadrant is the liver and gallbladder
right upper quadrant below diaphragm
cells making bile
hepatocytes
bile production and pathway include
Hepatocytes (liver cells) make bile →Bile canaliculi → bile ducts → hepatic duct → Gallbladder (green, pear-shaped organ that stores bile) →Cystic duct → common bile duct → duodenum
Functional unit is lobule
liver
Consists of hepatocytes in rows that radiate around central vein
lobule
permeable capillaries with phagocytic [Kuppfer] cells)
sinusoids
sinusoids are located in what in liver
cells
Blood reaches liver lobules from what vessels
hepatic artery
hepatic portal vein
branch of celiac artery that has a blood high in O2
hepatic artery
(formed by veins from digestive organs and spleen) where blood low in O2 but rich in nutrients from digestive organs
hepatic portal vein
function in emulsification and absorption of fats
bile
breaking apart clusters of fats so they are more digestible
emulsification
formation and recylling of bile is made possible due to what from heme when RBCs are broken down
bilirubin
gives feces brown color
stercobillin
reabsorbed into blood in small intestine (ileum) → portal vein → liver
bile salts
may form from bile
gallstones
Obstruct bile ducts from gallbladder → pain
gallstones
liver functions in (3)
carbohydrate metabolism
lipid metabolism
protein metabolism
❑Polysaccharide stored in liver as glycogen
❑Converts glycogen, fructose, galactose, lactic acid, amino acids → glucose to blood glucose
what function of liver
carbohydrate metabolism
❑Produces cholesterol, triglycerides; makes bile
❑makes lipoproteins for lipid transport
what function of liver
lipid metabolism
responsible for lipid transport
lipoproteins
Remove NH2 from amino acids → ammonia (NH3) → urea → to kidneys (urine)
Synthesize most plasma proteins: albumin
what function of liver
protein metabolism
❑Detoxifies alcohol
❑Inactivates steroid and thyroid hormones
❑Eliminates some drugs (like penicillin) into bile
what liver function
Removes many harmful substances from blood
what function of liver
❑From heme (in RBCs) to bile → feces
excretion of bilirubin
Stores fat-soluble vitamins (ADEK) and minerals (Fe, Cu)
liver
Activates vitamin D
liver
Length
❑10 feet long in living person
❑Extends from pylorus of stomach to cecum of large intestine
small intesitne
Three major regions or small intestine
duodenum, jejunum, ileum
❑Site of most of digestion
❑Essentially all nutrient absorption occurs here
small intestine
Ends in ileocecal sphincter
small intestine
what quadrant does small intestine end
right lower quadrant
Same 4 layers but with modifications epithelium in mucosa is simple columnar
small intestine
has Absorptive cells with microvilli and goblet cells
small intestines
cells that secrete mucus in small intestine
goblet cells
secrete
❑Enzymes that complete digestion
❑Secretin, cholecystokinin (CCK), glucose-dependent insulinotropic peptide (GIP)
intestinal glands
tissue within the wall of small intestine that act in defense
lymphatic tissue
has duodenal glands →Alkaline mucus → helps neutralize stomach acid
what layer of small intestine
submucosa
present In mucosa and submucosa of small intestine; increase surface area
circular folds
fingerlike projections of mucosa
villi
Increase absorptive surface area
villi
Contain vessels that absorb nutrients
villi
the lymphatic vessels of the small intestine which absorb digested fats
lacteal
Segmentation activity: for mixing
Peristalsis for movement of intestinal contents after most absorption completed: slow waves
what kind of digestion in small intestine
mechanical digestion
2 L/d of secretions
what kind of digestion
chemical digestion
what pH of chyme due to bicarbonate
alkaline
became alkaline From pancreas and alkaline mucus from small intestine
alkaline chyme
breaks small peptides
peptidase
sucrase, lactase, and galactase
disaccharidases
enters small intestine carrying partially digested carbohydrates and proteins
chyme
(composed of bile, pancreatic juice, intestinal juice) completes digestion
intestinal juice
90% of absorption of products of digestion occurs in the
small intestine
❑Monosaccharides; amino acids
❑Fatty acids and monoglycerides
❑Phosphate sugar, and bases of DNA, RNA
are absorbed in what organ
small intesinte
(salivary and pancreatic): that convert
Starch and dextrin → maltose
amylase
convert maltose → glucose + glucose
maltase
covert lactose → glucose + galactose
lactase
convert sucrose → glucose + fructose
sucrase
Pepsin, trypsin, chymotrypsin, and carboxypeptidase converts ___ to small peptides
proteins
pancreatic enzyme that convert triglycerides > fatty acids + monoglycerides
lipase
absorption of products of digestion in what processes (4)
diffusion
facilitated diffusion
osmosis
active transport
carbohydrates are converted to what Via portal system (blood) to liver
monosaccharides
proteins are converted to what via portal system (blood) to liver
amino acids
short-chained fatty acids or monoglycerides go to what
blood
lipids that are coated by proteins in chlyomicrons → lacteals → lymphatics (lymph) → then blood
larger
Primarily osmotic movement that accompanies other nutrients
what kind of particles
water and salt
vitamins absorbed with fat
fat-soluble vitamins
fat soluble vitamins include
A, D, E, K
vitamins that are digested with simple diffusion
water soluble
Combines with intrinsic factor for transport through duodenum and jejunum
Finally can be absorbed by active transport in ileum
B12
4 regions of large intestine
cecum
colon
rectum
anal canal
Ileocecal sphincter
Appendix attached
what region of large intestine
cecum
ascending, transverse, descending and sigmoid
what part of large intestine
colon
has goblet cells secrete mucus
what layer of large intestine
mucosa
has incomplete ____ muscularis layer in large intestine
longitudinal
limits rate of emptying of ileum
ileocecal sphincter
❑Triggered by presence of food in stomach
❑Wastes move from mid-colon → rectum
what kind of peristalsis
mass persitalsis
❑Produce some B-vitamins + vitamin K
❑Produce gases: flatus
❑Colon absorbs salt + water
what kind of digestion
bacterial digestion
Stretch of rectum wall → neural reflex → contraction of longitudinal muscle
defecation reflex
Combined pressure + parasympathetic activity→ contracts/relaxes internal anal sphincter
relaxes
External anal sphincter is voluntary/involuntary
voluntary
Contraction of diaphragm and abdominal muscles aid what process
defecation
rule: activate forward and inhibit behind
digestion
three phases of digestion
cephalic
gastric
intestinal
phases of digestion smell, sight, thought of food
cephalic
what cranial nerves stimulate salivary glands
VII
IX
what cranial nerve stimualte gastric glands
cranial nerve X
stretching, pH of stomach
what phase of digestion
gastric
activates stomach and relaxes pyloric sphincter
gastrin
intestinal hormones play key roles
what phase of digestion
intestinal
❑Released when acidic chyme enters intestine
❑Stimulates release of pancreatic juice high in bicarbonate to buffer acidic chyme from stomach
secretin
◼Released when chyme rich in amino acids and fatty acids enters intestine
◼Stimulates release of pancreatic juice high in digestive enzymes
◼Decreases gastric motility and secretion
◼Causes gallbladder to contract and eject bile
cholecystokinin (CCK)
Decreased GI secretion, motility, strength of responses
Loss of taste, increased risk for periodontal disease, difficulty swallowing, hiatal hernia, gastritis, peptic ulcer disease
Increased risk for gallbladder problems, cirrhosis of liver, pancreatitis, constipation, hemorrhoids, diverticulitis
aging
