Digestive System I Flashcards
Another name for the Gastrointestinal (GI) tract
Alimentary Canal
Urgans of the GI track include the mouth, most of the pharynx, esophagus, stomach, small intestine, and large intestine.
Alimentary Canal
tongue (PB), teeth (PB), salivary glands (S), pancreas (S), liver (S), and gallbladder (S)
Accessory Digestive organs
these organs come in direct contact with food and help to physically break it down.
Tongue & teeth
these organs produce or store secretions that will reach the digestive tract via ducts; never in contact with food directly; secretions for chemical breakdown of food.
Salivary glands, pancreas, live and gallbladder
1) Ingestion
2) Secretion
3) Mixing and Propulsion (i.e., Motility Capability)
4) Digestion
a. Mechanical Digestion
b. Chemical Digestion
5) Absorption
6) Defecation (of Feces)
7) Barrier
8) Immunologic Protection
Major processes of Digestive System
What is the mouth referred to as
Oral or Buccal cavity
Bound by the cheeks, hard and soft palates, tongue, and floor of the mouth
Oral cavity
Fleshy folds that surround the opening of the mouth and contain the orbicularis oris muscle
Lips or labia
Location of a mucocutaneous junction.
lips
The oral cavity opens into the oropharynx through an opening called the
fauces
Between the lips and teeth and between the cheeks and teeth.
Vestibule
Superior border is the hard and soft palates; inferior border is the tongue and floor of the mouth; the posterior border in the entrance into the oropharynx; all other borders are the teeth.
Oral Cavity Proper
- 99.5% water and 0.5% solutes
- average secretion of 1000ml/day to 1500ml/day
Saliva
- Moisten oral mucosa
- Moisten dry foods
- Provide medium for food materials to dissolve so they can chemically stimulate taste buds
- Buffer contents of oral cavity (bicarbonate and phosphate ions)
- Contains amylase that partially breaks down starch (i.e. polysaccharide)
Salivas protective and digestive roles
Buffer contents of the oral cavity
Bicarbonate and phosphate ion
Breaks down starch
amylase
connects nasal and oral cavities to larynx and esophagus
Pharynx
passageway for food and air
Pharynx
Divisions of the pharynx
Nasopharynx, Oropharynx & laryngopharynx
Epithelium in the pharynx
Respiratory epithelium & some stratified squamous
Found posterior to the nasal cavity
Nasopharynx
Posterior to oral cavity
Oropharynx
Begins at the level of the superior border of the upright epiglottis and opens into the esophagus and larynx
Laryngopharynx
Epithelium in nasopharynx
Ciliated pseudostratified columnar epithelium
Epithelium in Oropharynx
nonkeratinized stratified squamous epithelium
Epithelium in Laryngopharynx
nonkeratinized stratified squamous epithelium
Air and food passageways
Oropharynx and Laryngopharynx
Air passageway only
Nasopharynx
Superior to soft palate; when swallowing the soft palate and the uvula move superiorly to close off the what
Nasopharynx
Posterior to oral cavity; between level of soft palate to the epiglotti
Oropharynx
What is continuous with both the esophagus and the larynx; extends from an upright epiglottis to the larynx
Laryngopharynx
Parts of the mucosa
- Lining epithelium
- Lamina propria
- Muscularis mucosae
From the lumen outward
- Mucosa
- submucosa
- Muscularis externa
- Serosa or Adventitia
Epithelium of lining epithelium of mucosa
Nonkeratinized stratified squamous & Simple columnar