Chapter 16: Digestive System Flashcards
What are the parts of the small intestine in order?
Duodenum, Jejunum, ileum
What are the parts of the large intestine in order?
cecum, ascending colon, transverse colon, sigmoid colon, rectum, anal canal, anus
what are the functions of the digestive system
ingestion and mastication, digestion, absorption of nutrients, elimination
What is mechanical digestion
physical breakdown of food (chewing)
what is chemical digestion
chemical breakdown of food (amylase)
what are simple sugars absorbed from
carbohydrates
what are amino acids absorbed from
proteins
what are fatty acids and monoglycerides absorbed from
lipids
what are the macronutrients
carbohydrates, lipids, proteins
what is the nutrient pool’s purpose
it is needed for ATP production and building molecules
what are the four layers of the digestive tract (inner to outer)
mucosa, submucosa, muscularis, serosa
what is the mucosa
stratified squamous epithelium and simple columnar epithelium that lines the inside of the digestive tract
what is the submucosa
loose connective tissue, blood vessels, lacteals, nerve fibers
what is the muscularis
smooth muscle; composed of inner circular layer and an outer longitudinal layer
what is the serosa
the visceral peritoneum
what is the purpose of the lesser omentum and the greater omentum
adipose storage
what is the term for organs that are outside the peritoneum
retroperitoneal
what are the retroperitoneal organs
pancreas, kidney, duodenum
what is mastication
chewing
where is the parotid gland located
in front of the ear
where is the submandibular gland located
under the angle of the mandible
where is the sublingual gland located
under the tongue
what is the term for a ball of food mixed with saliva
bolus
what is the term for an enzyme that breaks starch into maltose
salivary amylase
what is deglutition
swallowing
maltose is the product of what, after amylase breaks it down
starch
Where does peristalsis occur
the esophagus, stomach, small and large intestine
What is peristalsis
wave-like contractions that move food forward along the digestive tract
What is the term for an opening in the diaphragm where the esophagus connects to the stomach
esophageal hiatus
what is the name of the sphincter where the esophagus and stomach meet
lower esophageal sphincter
What is the term for the stomach and/or intestines pushing up into the esophageal hiatus
hiatal hernia (diaphragmatic hernia)
What are some complications associate with hiatal hernias
barrett’s’ esophagus
what does barretts esophagus do to the body
causes cancer and a changes in the lining
What is a more common form of hiatal hernia
sliding hernia
what is the less common but more serious form of a hiatal hernia
paraesophageal hernia
What is the term for an overgrowth of the pyloric sphincter that results in projectile vomiting that can occur in the first 6 months of life and more commonly in males
hypertrophic pyloric stenosis
What is the term for narrow openings of gastric glands
gastric pits
What are 4 cell types of the gastric glands
mucous neck cells, parietal cells, chief cells, endocrine cells
what is the purpose of mucous neck cells
produce mucus
what is the purpose of parietal cells
produce HCl and IF
what is the purpose of chief cells
produce pepsinogen
what is the purpose of endocrine cells
produce gastrin
What does protein digestion in the stomach involve
pepsinogen and hydrochloric acid
What happens in the stomach lumen during protein digestion
pepsinogen becomes pepsin which is activated by HCl; pepsin is then able to break protein down into polypeptides
What is intrinsic factor
fluid produced by the stomach that is necessary for absorption of B12
what happens when there is a lack of B12 in the body
pernicious anemia
What is the term for localized contractions that keep chyme in a small region of the small intestine and enhances chemical digestion and absorption through this process
segmental contraction
what is the origin of gastrin
stomach, duodenum
what is the target of gastrin
stomach
what is the action of gastrin
promotes gastric secretions (HCl and pepsinogen) and increases gastric mobility
what is the origin of cholecystokinin
stomach, gallbladder, pancreas
what is the action of cholecystokinin
inhibits gastric secretions and mobility (slows empty); stimulates the release of bile into duodenum; stimulates release of pancreatic enzymes
what is the cause of hunger
ghrelin
What are structures that increase surface area in the digestive tract
plicae, villi, microvilli
what are plicae
wrinkles in the lining of the small intestine, macroscopic
what are villi
macroscopic type fingerlike projections on intestinal wall
what are microvilli
microscopic fingerlike projections on cell membrane
what do microvilli compose
the brush border
what are lacteals
lymphatic capillaries in villi - absorb dietary fat
what type of epithelium is along the small intestine
simple columnar epithelium
what is the term for “pulpy/pasty” food mixed with digestive juices
chyme
what are the functions of peptidases
turn peptides into amino acids
what is the function of sucrase
turn sucrose into glucose and fructose
what is the function of maltase
turn maltose into two glucose
what is the function of lactase
turn lactose into glucose and galactose
what is the function of lipase
turn triglycerides into fatty acids and monoglycerides
stretch reflexes stimulate the movement of food along the digestive tract by
activating the vagus nerve/parasympathetic division
what are carbohydrates broken down into
polysaccharides –> disaccharides –> monosaccharides
what are the functional units of the liver
liver lobules
what are hepatocytes and what do they do
liver cells, produce bile
what do bile canaliculi do
transport bile to hepatic ducts
what are Kuppfer cells
liver macrophages (acts as phagocytes)
what is the function of the gall bladder
store bile
what is the term for gall stones
cholelithiasis
what is the term for inflammation of the gallbladder
cholecystitis
what is the term for the removal of the gallbladder
cholecystectomy
what does chole mean
bile
what does lithos mean
stone
what does cystic mean
bladder
what is the composition of bile
bile salts, bile pigments, cholesterol, water
what is emulsification
the mixing of fats with water
what is a term for the yellow-orange appearance of skin caused by bile pigments accumulating under the skin
jaundice
what is the term for inflammation of the liver
hepatitis
what can hepatitis cause
jaundice
What are the functions of the liver
digestion, nutrient storage, nutrient conversion, detoxify, synthesize plasma proteins
what does the liver store
glucose as glycogen, fat-soluble vitamins, iron
what is a nutrient conversion that takes place in the liver
amino acids to fat or glucose
what does the liver do to detoxify the body
convert ammonia to urea, detox alchohol
what is another term for endocrine cells
pancreatic islets
what are the pancreatic islets
alpha cells and beta cells
what do alpha cells do
produce glucagon
what do beta cells do
produce insulin
what do acini cells do
produce enzymes and sodium bicarbonate and release them into ducts
What does pancreatic amylase do
turn starch into maltose
what does pancreatic lipase do
turn triglycerides into fatty acids and monoglycerides
what does trypsin (trypsinogen - inactive) do
turn polypeptides into peptides
what does chymotrypsin (chymotrypsinogen - inactive) do
turn polypeptides into peptides
what does carboxypeptidase (procarboxypeptidase - inactive) do
turn peptides into amino acids
What does secretin do
stimulate release of sodium bicarbonate, reduces acidity (increases pH) of chyme
what does cholecystokinin do
stimulates pancreatic enzyme release
what is the term for inflamed rectal veins
hemorrhoids
what type of muscle controls the internal anal sphincter
smooth muscle
what type of muscle controls the external anal sphincter
skeletal muscle
what anal sphincter do you have control over
the external anal sphincter
What are the functions of the large intestine
absorption (water, vitamins, bile pigments, bile salts, toxins); production of vitamins by microbiome
what vitamins are produced by the large intestine
b and k vitamins through use of gut microbes
what are mass movements
powerful contractions that moves feces to end of digestive tract
when do mass movements occur and where
after a meal; only in the large intestine
glucose and amino acids are absorbed by _______ with ____ and __________ and transported with blood
cotransport; sodium ions; facilitated diffusion
what are the steps during lipid absorption and transport
bile emulsifies fat –> triglycerides are affected by lipase —> fatty acids and monoglycerides formed –> interact with bile salts to form micelles
what are the three types of lipoproteins
chylomicron, LDL, HDL
Which lipoprotein makes up a very small amount of cholesterol
chylomicron
which lipoproteins makes up a majority of cholesterol
LDL, HDL
Which lipoprotein is considered healthy fat
HDL
which lipoprotein is formed inside the small intestine cells
chylomicron
which lipoprotein has the highest proportion of fat
chylomicron
which lipoprotein is absorbed by lacteals
chylomicron
why are proteases release in inactive form
because if released in active form, they will react with our body cells
