digestive system one Flashcards
tube that extends from mouth (oral cavity) to anal canal
gastrointestinal (GI) tract
what makes up the GI tract?
oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, and anal canal
muscular waves of contraction, keeps food moving along the tract
peristalsis
what is the result of reverse peristalsis (retroperistalsis)?
vomiting
what are the functions of the digestive system?
digestion, absorption, and elimination of wastes
what are the two types of digestion?
mechanical and chemical
chewing and churning of food
mechanical digestion
using enzymes to break down food/bonds that bind food
chemical digestion
process of breaking down food into small fragments
digestion
water and food molecules pass through intestines to GI lymphatics (lacteals) and blood vessels
absorption
absorb dietary lipids and lipid-soluble vitamins
GI lymphatics (lacteals)
absorb other digested nutrients
blood vessels
not part of GI tract, but assist with digestion
accessory digestive organs
what are the accessory digestive organs?
tongue, teeth, salivary glands, liver, gallbladder, pancreas
true or false, the abdominopelvic cavity is lined by peritoneum
true
lines abdominal wall
parietal peritoneum
covers abdominal organs
visceral peritoneum
where the GI tract and most abdominopelvic organs are located
- sits between the two layers of peritoneum
peritoneal cavity
what controls the digestive system?
autonomic nervous system
in general, it stimulates/increases activity of GI tract (rest and digest)
parasympathetic
in general it inhibits/decreases activity of GI tract
sympathetic
what is the oral cavity continuous with?
oropharynx
what type of tissue makes up the oral cavity?
nonkeratinized stratified squamous epithelium
why is the oral cavity lined with nonkeratinized stratified squamous epithelium?
for rougher food that might be consumed
what are the four types of teeth?
incisors, canines, premolars, molars
in front of oral cavity
incisors (2)
sharp tooth; pierce food
canines (1)
grind food
premolars
how many molars do you have in each quadrant?
three
which molar is your wisdom tooth?
3rd molar
what do kids lack in their teeth?
premolars (only have 2 molars)
skeletal muscle covered with stratified squamous epithelium
- will be exposed to abrasive materials
tongue
what cranial nerve does the motor innervation for the tongue?
hypoglossal
what cranial nerve(s) do taste for the tongue?
glossopharyngeal and facial
what cranial nerve owes the sensation for the tongue?
trigeminal
anterior 2/3 of palate, bony
hard palate
what bones make up the hard palate?
palatine bone and palatine portion of maxilla
posterior 1/3, formed from skeletal muscle
- uvula
soft palate
what is the function of the uvula?
rise to close off nasopharynx when we swallow so we don’t shoot things through our nose
what are the three pairs of salivary glands?
parotid, submandibular, and sublingual glands
what cranial nerve is associated with the parotid gland?
glossopharyngeal
what cranial nerve is associated with the submandibular and sublingual glands?
facial
what is the function of salivary glands?
secrete saliva
what are the functions of saliva?
- dissolves food molecules so they can be tasted
- moistens food, aids in compacting into bolus (ball)
- cleanses mouth
- chemical digestion of carbohydrates (with salivary amylase)
what inhibits bacterial growth in mouth?
lysozyme and antibodies in saliva
muscular tube that connects nasal cavity and mouth to larynx and esophagus
- “throat”
pharynx
what is the function of the pharynx?
skeletal muscle helps “voluntarily” propel stuff from the mouth into the esophagus (voluntary swallowing)
what part of the pharynx conducts both air and food?
oropharynx and laryngopharynx
what type of epithelium lines the nasopharynx?
pseudostratified ciliated columnar epithelium
what epithelium lines the oropharynx and laryngopharynx?
nonkeratinized stratified squamous epithelium
what are the four tunics of the GI tract?
mucosa, submucosa, muscularis, and adventitia (serosa)
innermost tunic
mucosa
what are the three layers of the mucosa?
epithelium, lamina propia (areolar connective tissue), muscularis mucosae (thin layer of smooth muscle)
what makes up the submucosa?
connective tissue and contains major blood vessels
what two smooth muscle layers make up the muscularis?
inner circular layer and outer longitudinal layer
which layer is responsible for peristalsis?
muscularis
outermost layer
serosa or adventitia
visceral peritoneum and areolar connective tissue
serosa
areolar connective tissue only
adventitia
