Ch 26A (Digestive System) Flashcards
what are two categories of organs in the digestive system?
gastrointestinal tract & accessory digestive organs
the GI tract is a continuous tube including:
(1) oral cavity
(2) pharynx
(3) esophagus
(4) stomach
(5) small & large intestine
(6) anal canal
what is connected to the GI tract but is not a part of it?
accessory digestive organs
what structures are accessory digestive organs?
(1) teeth & tongue
(2) salivary glands
(3) liver
(4) gallbladder
(5) pancreas
main functions of the digestive system include
(1) ingestion
(2) motility (peristalsis)
(3) secretion
(4) digestion (mech or chem)
(5) absorption
(6) elimination of wastes
what is the GI tract wall composed of?
4 tunics (layers)
name the 4 GI tract wall tunics from deep to superficial
(1) mucosa
(2) submucosa
(3) muscularis
(4) serosa
name the regions of the oral cavity
vestibule & oral cavity proper
anterior 2/3 of tongue, palatine processes of maxillae bones & palatine bones
hard palate
posterior 1/3 of the tongue, muscular
soft palate
this structure extends posteriorly from soft palate & elevates during swallowing to close off posterior entrance to nasopharyngeal
uvula
this structure is primarily skeletal muscle
tongue
function of the tongue
manipulates & mixes ingested materials & assists in swallowing
covers the surface of the tongue
papillae
thin midline tissue that attaches inferior part of tongue to oral cavity
lingual frenulum
this structure produces & secrets saliva into the oral cavity
salivary glands
what are main functions of the salivary glands?
(1) moistens ingested materials to become a slick bolus
(2) moistens, cleanses & lubricates oral cavity structures
(3) dissolves food so taste receptors on tongue can be stimulated
what structures makes up the majority of the saliva?
extrinsic salivary glands
this structure secretes 25-30% of total saliva and is the largest of the extrinsic glands
parotid salivary glands
where is the parotid salivary glands located?
anterior and inferior to the ear
this structure runs parallel to the zygomatic arch, pierces buccinator before opening into mouth near upper 2nd molar
parotid duct
this structure produces 60-70& of total saliva
submandibular salivary glands
where is the submandibular salivary glands located?
inferior to body of mandible
this structure opens in the floor of the mouth next to lingual frenulum
submandibular duct
this structure produces 3-5% of total saliva
sublingual salivary ducts
where is the sublingual salivary glands located?
inferior to the tongue
this structure opens into the inferior surface of oral cavity
sublingual ducts
name the types of extrinsic salivary glands
(1) parotid
(2) submandibular
(3) sublingual
this is the part of the tooth that is visible
the crown
hardest substance in the tooth
enamel
tooth narrows
neck
parts of tooth embedded in bone
roots
another way to say gums
gingiva
this forms most of the tooth
dentin
this part of the tooth contains arteries, veins & nerves
pulp cavity
space in the root of the tooth
root canal
list the different surfaces of the teeth
(1) mesial surface
(2) distal surface
(3) buccal surface
(4) labial surface
(5) lingual surface
(6) occlusal surface
surface facing away from back molar
mesial surface
surface facing toward back molar
distal surface
outer surface of lateral facing teeth
buccal surface
front surface of front teeth
labial surface
inner surface of all teeth
lingual surface
chewing surfaces
occlusal surface
this set of teeth erupt between 6-30 months
deciduous teeth/milk teeth
this set of teeth replaces the deciduous teeth
permanent teeth
how many deciduous teeth are there in comparison to permanent teeth?
20 deciduous teeth, 32 permanent teeth
list the permanent teeth types
(1) incisors
(2) canines
(3) premolars
(4) molars
this teeth type is the most anterior, shaped like chisels for slicing
incisors
this teeth type is posterolateral to incisors, pointed for puncturing & tearing
canines
this teeth type is posterolateral to canines, have flat crowns w/ ridges for crushing & grinding
premolars
this teeth type is the thickest and most posterior teeth, and adapted for crushing and grinding
molars
how is food routed into the esophagus?
by closure of the epiglottis during swallowing
conducts ingested materials from pharynx to stomach
esophagus
what does the esophagus pass through before connecting to the stomach?
an opening in the diaphragm called the esophageal hiatus
closes during inhalation preventing air entry
superior esophageal
prevents materials from regurgitating from stomach
inferior esophageal
rhythmic contraction of digestive tubes
peristalsis
what is the general path of peristalsis?
begins in the esophagus, continues through GI tract and pushing the bolus along
when is peristalsis controlled voluntarily, slightly voluntarily, and involuntarily?
(1) top 1/3 of esophagus
(2) middle 1/3 of esophagus
(3) involuntary after 2/3
where is the stomach located?
in the upper left quadrant of the abdominal cavity
what is the function of the stomach?
mechanical and chemical digestion of the bolus which processes into chyme
