Lab Quiz 8: Digestive System Anatomy Flashcards
composed of a hollow tube that runs from the mouth to the anus and is technically “outside” the body
digestive tract (ailmentary canal)
organs that are part of the digestive tract
- mouth
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
secrete digestive products into the canal
accessory organs
accessory organs of the digestive system
- pancreas
- liver
- gallbladder
- salivary glands
functions:
* secretion of mucous and enzymes
* absorption, protection (bacteria, enzymes)
mucosa
made up of connective tissue, contains the parasympathetic submucosal plexus
submucosa
smooth muscle, inner layer = circular, outer layer = longitudinal; contains myenteric plexus
muscularis
what types of fibers does the muscularis contain
parasympathetic fibers
functions to reduce friction and helps anchor organs in place
serosa (visceral peritoneum)
types of digestion
mechanical and chemical
functions of the digestive system
- ingestion (followed by propulsion)
- digestion (mechanical and chemical)
- absorption
- defecation
blood supply for the alimentary canal would come from
- celiac trunk (gastric, hepatic, splenic a.)
- superior and inferior mesenteric arteries
arise from abdominal aorta
the alimentary canal begins where
oral cavity
which bones form the hard palate
- palatine bone
- palatine process of maxilla
what is meant by the 2123 dental formula
- 2 incisors
- one canine
- 2 premolars
- three molars
in each quadrant
which cranial nerve controls the tongue
hypoglossal (CN XII)
the swallowing reflex is initiated in which region of the body
pharynx
common passageway for food and air
pharynx
entrance into stomach from esophagus
gastroesophageal junction
- about 10in long
- lies posterior to trachea against spine
esophagus
the superior esophagus is made up of what type of muscle
skeletal
the inferior esophagus is made up of what type of muscle
smooth
the esophagus is lined with what type of epithelia
stratified squamous
most of the organs of the abdominal cavity are covered with a serous membrane called
the peritoneum
blockage of any pancreatic structures and can lead to the digestion of pancreas by its own enzymes
pancreatitis
opening into the small intestine from the pancreas
major duodenal papilla
- lies posterior to stomach in the retroperitoneal space with its head projecting near the duodenum
- produces many important enzymes that are used in the small intestine
pancreas
pathway for pancreatic enzymes, joins the common bile duct as the hepatopancreatic ampulla (ampulla of Vater)
pancreatic duct
a sphincter that leads from the ampulla of Vater and allows digestive products into the small intestine
hepatopancreatic sphincter (sphincter of Oddi)
salivary glands
- parotid
- submandibular
- sublingual
what are the perfect conditions for gallstones
- fair
- fat
- forty
- female
- fertile
5 Fs
pathway of the release of bile
- cystic duct
- hepatic duct (liver)
- common bile duct
- hangs from the inferior surface of the liver
- stores and concentrates bile
gallbladder
emulsifies fat
bile
attaches liver to diaphragm
falciform ligament
anterior to ear, empties above second molar
parotid gland
inside arch of the mandible, empties under the tongue
submandibular gland
- under the tongue, empties under the tongue
- secretes mucin and salivary amylase which begins the digestion of starches
sublingual gland
lobes of the liver (4)
right, left, caudate, quadrate
true or false
you can live without a lobe of your liver
true
the liver receives blood from digestive organs via
the hepatic portal vein
blood to the liver is supplied from
the celiac trunk (hepatic a.)
muscularis layer reduced to 3 longitudeinal bands in the Large Intestine
teniae coli
small pocket-like sacs created when teniae coli contract (folds)
haustra
functions of the large intestine
- consolidate and move unusable fecal material out of the body
- site of vitamin B and K manufacture by bacteria
- reclaims most water and some electrolytes from undigested food
pathway of the external large intestine
- cecum
- ascending colon
- hepatic flexure
- transverse colon
- splenic fissure
- descending colon
- sigmoid colon
- rectum
- anus
fats are absorbed into specialized lymphatic structures here
lacteals
- lies in LUQ
- J-shaped with 4 major regions: cardia, fundus, body, pylorus
stomach
mucosa of the stomach is composed of what type of epithelia
simple columnar epithelia
2 valves of the stomach
cardiac sphincter (LES) and pyloric sphincter
attachment of omenta is where on the stomach
greater and lesser curvatures
inreases surface area, contains gastric pits
rugae of the stomach
which layer of the stomach has an added oblique layer to add to the churning action of teh stomach
muscularis
parts of the duodenum
- hepatopancreatic ampulla and sphincter
- major duodenal papilla
responsible for digestion and absorption; first 12” of the small intestine
duodenum
responsible for digestion and absorption; middle 6’ of the small intestine
jejunum
responsible for compaction and absorption; last part of the small intestine
ileum
located between the ileum (SI) and cecum (LI)
ileocecal valve
functions of the pilcae circularis, villi, microvilli in SI
increase surface area
hydrolytic enzymes bound to microvilli and used in digestion
brush border of the SI
carbohydrates, lipids, and proteins are broken down to their component molecules and absorbed through where
Villi of SI
- the upper esophageal sphincter is contracted (closed)
- the tongue presses hard against the hard palate, forcing the food bolus into the oropharynx
buccal phase of movement of food into the stomach
- the tongue blocks the mouth
- the soft palate and its uvula rise, closing off the nasopharynx
- the larynx rises so that the epiglottis blocks the trachea
- the upper esophageal sphincter relaxes; food enters the esophagus
- constrictor muscles of the pharynx contract, forcing food into esophagus inferiorly
- upper esophageal sphincter contracts after food enters
pharyngeal-esophageal phase of movement of food to the stomach
moves food through the esophagus to the stomach
peristalsis
final stage of food moving to the stomach
gastroesophageal sphincter surrounding the cardial orifice opens; after food enters the stomach, the sphincter closes, preventing regurgitation
secretions from the stomach
- mucus
- hydrochloric acid (HCl)
- pepsinogen
- gastrin
secrete gastrin
enteroendocrine cells
important for hunger response and stomach motility
gastrin
secrete pepsinogen
chief cells
important for protein digestion
chief cells
secrete HCl
parietal cells
important for protein digestion, and intrinsic factor-vitamin B12 absorption
parietal cells
secretes mucus
mucous cells
coats and protects the stomach lining
mucus
which cranial nerves carry taste information
CN VII, CN IX, CN X
facial, glossopharyngeal, and vagus respectively
are salivary glands sympathetic or parasympathetically controlled?
parasympathetically
sum of all biological reactions happening in the body
metabolism
types of metabolism
- catabolism
- anabolism
reactions that break larger molecules down into smaller parts; releases energy
catabolism
are molecules that:
* are not changed or destroyed in a chemical rxn
* lower energy needed to break bonds of reactants (activation energy)
* speed up the rate of a reaction
catalysts
reactions used to build larger molecules from smaller precursors; uses energy
anabolism
- accomplished by enzymes that act as catalysts
- breaking of chemical bonds using water, which hold the molecules of food together (chemical digestion)
hydrolysis
most common forms of lipid in the body
triglycerides
other forms include cholesterol, phospholipids, and steroids
which enzyme is present in the small intestine and what does it digest
pancreatic proteases: digest peptides into amino acids (located in duodenum)
brush border proteases: digests tri-, di- peptides into amino acids (located in brush border)
- nonpolar
- glycerol + fatty acids
- storage molecules that yield 2x as much energy as other macromolecules when catabolized
lipids
bile digests what molecule and where
lipids into glycerol and fatty acids and some monoglycerides; located in duodenum of small intestine
pancreatic lipases digest what where
emulsified lipids into glycerol and fatty acids and some monoglycerides in the duodenum of the small intestine
what is meant by specificity when referring to enzymes
enzymes have a specific 3D shape that is designed to fit molecules involved in only one type of reaction
what is meant by efficiency when referring to enzymes
most cellular reactions proceed at a rate 1.0 x 10^6 times faster with enzymes
factors that determine enzyme efficiency
- temperature
- pH
- concentration
- specificity
what is meant by concentration when referring to enzymes
higher [enzyme] = increased rxn rate
what happens if the environment an enzyme is in is too acidic or basic
enzyme denatures
what happens when an enzyme’s environment is too hot
enzyme denatures
what happens when an enzyme’s environment is too cold
enzyme is inhibited
plant-derived polysaccharides
starches, cellulose
animal derived polysaccharides
glycogen
polysaccharides are digested where using what enzyme
- where: oral cavity
- enzyme: salivary amylase
tri/disaccharides are digested where using what enzyme
where: duodenum of small intestine
enzyme: pancreatic amylase
sucrose, maltose, lactose are digested where and with what enzyme
- where: brush border of the small intestine
- enzyme: brush border amylase
