Card Set Information
hollow tube that wind through the body
alimentary canal or gi tract
The GI tract includes (7):
mouth, pharynx, esophagus, stomach, SI, LI and anus
The accessory digestive organs include:
teeth, tongue, gallbladder, salivary glands, liver and pancreas
__________ organs assist in the digestion of food material, but are not necessarily required.
The purpose of the digestive system is to acquire _______ and __________.
nutrients and water
T/F Food never enters the body.
True! it remains outside the body but passes through it
Alcohol is absorbed through the __________
nutrients are absorbed through the ____________-
water, electrolytes and vitamins are absorbed by the ______________
Absorbed nutrients are passed into _______ of the digestive system and then go into the _________.
Fats are absorbed through the small intestine and passed into the lymphatic system through a
fats will eventuall enter into the ______________ system
The ___________ colon is a storage site for feces.
There are 6 essential food-processing activities of the Digestive system:
ingestion, propulsion, mechanical disgestion, chemical digestions, absoption, defecation
Propultion = __________(party voluntary) and ______________ (involuntary movement of food)
swallowing and peristalsis
mechanical digestion = cheming, churning food in stomach and ___________. It occurs in the mouth, __________ and ___________.
segmentation, stomach, SI
CHemical disgestion = breakdown of food into molecules occurs in the _______, ____________, and _____________.
mouth, stomach, SI
Absorption= transporting nutrients/electrolyts/ water into __________; and fats into the ____________
elimination of indigestible substances
Peristalsis vs. Segmentation
Peristalsis utilizes coordination of these muscles to propel food through lumen.
Segmentation utilizes these muscles to mix rather than propel.
The organization for the entire length of the GI tract it: (4)
mucosa, submucosa, muscularis externa, serosa or adventitia
true epithelium+lamina propria+muscularis mucosae
*epithelium is either stratified squamous or simple columnar
contains arteries, veins, nerves, lymphatics and sometimes mucus glands
a layer of smooth muscle (muscularis)
a layer of mesothelium
serosa or adventitia
Enteric Nervous plexes
independent control of digestion
made up of submucosal and myenteric layers
Signals submucosal glands to secrete and muscularis mucosae to contract
located between the ciruclar and longitudinal layers of muscularis externa; controls peristalsis and segmentation
Ther are 4 mucosal types in the GI tract:
protective, secretory, absorptive and absorptive/protective
stratifies squamous epithelium found in the oral cavity, pharynx, esophagus and anal canal
simple columnar eithelium; specialized for secreting mucous; contains mucus-secreting cells and mucus-neck cells (stomach)
simple columnar cells; modified for absorbing nutrients (SI)
simple columnar cells; for absorbing water/electrolytes switching to stratified squamous; absorptive cells in LI, stratifies squamous in anal canal
the line between the tooth and gum
the space between the lip and the alveolar ridge
labial frenulum =lip to the gum
lingual frenulum = tongue to floor of oral cavity
Salivary glands open into the oral cavity ___________ and ____________.
under the tongue and through the cheek
the ________ dangles down from the soft palate
the lips are formed from _______ _____, and the cheeks are formed by the _____________ muscle
orbicularis oris, buccinator
Lateral arches of the soft palate:
palatoglossal arch (palate to tongue)
palatopharyngeal arch (palate to pharynx)
*palatine tonsils are between the two arches
The congue is covered with ___________.
papillae ARE NOT TASTE BUDS
A type of papillae that resembles pointed cones; most numerous; no tastebuds
A type of papillae that resemble mushrooms; possesses taste-buds
a papilla resembling a circular wall; possesses taste-buds
separates the circumvallate papilla and lingual tonsil
the opening between the oral cavity and the oropharynx
palatoglossal arch - uvula - sulcus terminalis
ring of protective tonsils in the oropharnyx = palatine + lingual tonsils
produce and deposit saliva into oral cavity
salivary gland made of serous cells; secrete amylase and lysozymes; parotid duct passes through buccinator muscle
enzyme to digest carbohydrates
enzyme to lyse bacteria
glands composed of mucous cells; secrete mucus for lubrication; utilizes many ducts
gland made of serous and mucous cells; usues the submandibular duct
Types/numbers of teeth per side
carries food material (bolus) from oral cavity to stomach
the upper 1/3 is _________ muscle
the middle 1/3 is ___________
the inferior 1/3 is __________ muscle
esophagus: The the lumen is collapsed except when
food passes through it
esophagus: the mucosa has a protective ____________ __________ epithelium
esophagus: there are __________ glands in the submucosa
*as the bolus passes the glands, they secrete mucus for lubrication
esophagus: the external layer is ________ not ___________.
adventitia not serosa
The esophagus passes through the diaphragm at the level of
The muscularis externa ______ function as the sphincter of the esophagus
muscle fibers of the diaphragm serve as a functional sphincter muscle in the esophagus
A site for chemical and mechanical digestion
Regions of the stomach (4)
cardiac, fundus, body, pyloris
a sphincter to prevent food from leaving the stomach
folds formed when stomach decreases in sizes
stomach: lined by modified simple columnar cells called "mucus-secreting cells"
T/F there are goblet cells in the stomach
FALSE, some texts are in error
secrete mucus and line the neck of the gastric pit
mucus neck cells
The mucus mucus protects the stomach from
The _______ and __________ of the stomach are called Gastric Pits
fundus and body
the gastric pits have ___________ glands
Types of cells in the gastric glands:
parietal cells, chief cells, enteroendocrine cells
What is the function of parietal cells?
secrete HCl and intrinsic factor (for absorption of Vitamin B12)
HCl makes pH=2 (hydrolyze food and kill microorganisms)
Function of cheif cells?
secrete Pepsin (protease) to breakdown proteins
Function of Enteroendocrine cells
When food enteres the stomach, _________ is produced
Gastrin stimulates Parietal cells to secrete
Has 3 layers of smooth muscle: innermost oblique, middle circular and outer longitudinal
The muscularis externa
The pyloric sphincter muscle is formed from a thinkened ______ ________ layer.
middle circular layer
A site for absorphtion of nutrients (carbs, proteins and fats)
Three parts of the SI
duodenum + jejunum + ileum
the duodenum begins after the _______ ___________.
the ileum ends at the ____________ _______.
Modified simple columnar cells for absorbing nutrients
specialized ducts of the lymphatic system to carry fats; absorptive cells transfer the emulsified fats into lacteal ducts
Lacteal vessels (or capillaries)
Mucus secreting cells in the SI
aggregated lymphoid nodules
(lymphoid tissue that appears as macroscopic white patches - only in the SI)
The muscularis externa has 2 layers of smooth muscle
The surface of the lumen has modifications to increase surface area for absorption such as:
plica circularis, villi, microvili,crypts, and paneth cells
Thinkened areas of submucosa
macroscopic finger-like projections of the mucosa
microscopic folds on apical surface of cells
located in SI between adjacent villi
crypts (of lieberkeuhn)
Located at he base of crypts; secrete lysozymes to lyse bacteria
Mucus secreting cells in the submucosa of the duodenum specifically
Food material entering duodenum stimulates the secretion of cholecystokinin and secretin
Signals the gallbladder to contract and release bile into the duodenum
Stimulates the pancrease to secrete digestive juices and bicarbonate into duodenum