Upper Alimentary Canal Flashcards
the mouth is also known as the
oral or buccal cavity
the mouth is bounded by
the cheeks, lips, palate, and tongue
the mouth is the only location for
ingestion
digestion begins in the
mouth
tongue initiates
swallowing
the cheeks form
the lateral walls of the mouth
the cheeks consist of
skin, subcutaneous fate, muscles, and an inner lining of stratified squamous epithelium
the lips (labia) are
highly sensative, highly mobile fleshly folds that surround the opening to the oral cavity
inner surface of each lip is attached to gum by
labial frenulum
vestibule is present between
cheeks/lips and gums/teeth
the tongue consists of
skeletal muscle and stratified squamous epithelium, which contains mucous glands
the tongue is attached to the floor of mouth by
lingual frenulum
upper and lateral surfaces of the tongue are covered with
numerous papillae
gives it rough texture
many papillae contain
taste buds
flood or mouth and undersurface of tongue are
richly supplied with blood vessels
soluble drugs get absorbed
very quickly
the palate separates
the oral cavity from the nasal cavity
anterior portion of palate is
hard (bony) palate
posterior portion of palate is
soft palate primarily of skeletal muscle
behind soft palate is
uvula which closes nasopharynx during swallowing
on either side of the uvula is
a paire of palatine tonsils
teeth
are the primary structures of mechanical digestion
adults have _____ permanent teeth
32
____ chisel like incisors for _______
8 for biting
___ pointed canines for _____
4 for tearing
___ broad pre-molars (bicsupids)
8
___ broad molars for ______
12 for crushing/grinding
the first set of 20 deciduous teeth erupt through gums between
six months and 2 years of age and get replaced between 6 and 17
each tooth is embedded in
a bony alveolus in the mandible or one of the maxillae
each alveolus is lined with
a periodontal ligament that anchors tooth in place
alveolar processes are covered by
gingivae (gums)
each tooth consists of a
crown above gum level
one to three roots embedded in the alveolar bone
a narrow neck where the crown and the root meet the gum
teeth consists mainly of
calcified connective tissue called dentin
dentin in crown and neck is covered by
enamel
enamel is
hardest substance in body (non-cellular secretion) are protects against wear and tear of chewing
dentin in root is covered by
bone-like cementum
each tooth has a central pulp cavity inside its
crown
each tooth has a root canal within each
root
pulp contains
blood vessels, nerves, and lymphatic vessels
blood vessels, lymphatic vessles, and nerves enter root canal through
apical foramen
a salivary gland is
any cell or organ that releases saliva into the oral cavity
intrinsic salivary glands can be found in
tongue, on inside of lips, on inside of cheeks which secrete relatively small amounts of saliva at a constant rate
extrinsic salivary glands are located
beyond oral mucosa and empty saliva into ducts
the are _____ pairs of extrinsic salivary glands
3
parotid glands are located
near ears, open into oral cavity by way of ducts near upper molars
submandibular glands are located
along the mandible; open into oral cavity via ducts near incisors
sublingual glands are located
in floor of mouth; open into oral cavity by way of ducts below tongue
extrinsic salivary glands secrete between
1.0 and 1.5 liters of saliva each day
salivation is controlled by
autonomic nervous system
parasymphathetic signals respond to
sight or aroma or taste of food and stimulates salivary glands to produce thin saliva rich in digestive enzymes
sympathetic signals respond to
stress and stimulate salivary glands to produce thick saliva with more mucus which makes mouth feel dry and sticky
saliva is mostly and does….
water and solutes and it moistens the mouth, digests some starch and lipids, cleanses teeth, inhibits bacterial growth, dissolves chemicals so they can stimulate the taste buds, and binds food particles together
salivary amylase and lingual lipase are
digestive enzymes present in saliva
salivary amylase digests
starch at neutral pH
lingual lipase digests
fats after it gets activated by stomach acids
lysozyme kills
bacteria (enzyme)
immunoglobin A inhibits
bacterial growth
mucus binds
food particles together and aids in swallowing
elctrolytes buffer
acidic foods that we ingest
ingesting food into the mouth triggers
an involunatary chewing response
tongue and other muscles manipulate
food and push it between teeth
masseter and temporalis muscles activate
jaws to start mastication
mastication
grinds food into pieces and mixes it with saliva to form a soft, flexible bolus which inititiates swallowing
some chemical digestion is initiated in ______, but
mouth, but very little absorption occurs
salivary amylase breaks
starch into maltose (disaccharide)
lingual lipase will eventually break
triglycerides into fatty acids and monoglycerides, after it has been activated in stomach
the pharynx is
a funnel shaped tube extending from the internal nares to the esophagus
the pharynx is composed of
skeletal muscle and lined with mucous membranes
swallowing (deglutination) is
a mechanism that moves food from the mouth to the stomach
swallowing is coordinated by
a swallowing center in the medulla oblongata and pons, which requires 22 separate muscle groups to work together
during voluntary buccal phase, tongue
pushes bolus of food into oropharynx
bolus of food in oropharynx triggers
involuntary pharyngeal phase
during pharyngeal phase
soft palate and uvula close off nasopharynx and epiglottis closes off the glottis so bolus of food can only enter esophagus
the esophagus is
a muscular, collapsable tube that lies posterior to the trachea
mucosa in esophagus contains
non-keratinized stratified squamous epithelium to protect esophagus from abrasion caused by swallowing food particles
submucosa of esophagus contains
esophageal glands that secrete lubricating mucus
superior end of muscularis is
skeletal muscles
inferior end of muscularis is
smooth muscle
__________ attaches esophagus to surrounding structures of connective tissue
adventitia
a bolus of food enters the esophagus through the
upper esophageal sphincter
during esophageal phase of swallowing
peristalsis pushes bolus of food through esophagus toward stomach
belching is created by
relaxing upper esophageal sphincter
the bolus of food enters the stomach through the
lower esophageal sphincter
if the lower esophageal sphincter fails to close,
stomach contects can enter lower esophagus
acidity of gastric secretions in lower esophagus may
irritate the wall of esophagus and cause heartburn
