Chapter 14 Part A: Digestive System

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Terms in this set (...)

Alimentary canal
is a hollow tube that winds through the ventral body and is open on both ends
Alimentary canal's organs
mouth, pharynx, esophagus, stomach, small intestine, and large intestine
Mouth
food enters the digestive tract through a mucous membrane-lined cavity
Lips
protects the mouth's anterior opening
Cheeks
forms the mouth's lateral walls
Hard palate
forms the mouth's anterior roof
Soft palate
forms the mouth's posterior roof
Uvula
is a fleshy projection of the soft palate, which extends inferiorly from the posterior edge of the soft palate
Vestibule
is the space between the lips and cheeks externally and the teeth and gums internally
Oral cavity proper
the area contained by the teeth
Tongue
occupies the floor of the mouth
Lingual frenulum
a fold of mucous membrane, secures the tongue to the floor of the mouth and limits its posterior movements
Palatine tonsils
at the posterior end of the oral cavity are paired masses of lymphatic tissue
Lingual tonsil
covers the base of the tongue
Lingual & Palatine tonsils
The tonsils, along with the lymphatic tissue defend the body. When they become inflamed and enlarged, they partially block the entrance of the throat making it difficult to swallow
Mastication
the act of chewing
Oropharynx
posterior to the oral cavity
Laryngopharynx
is the continuous of the esophagus
Pharynx
the throat
Walls of the Pharynx
consists of two skeletal muscle layers
Esophagus
runs from the pharynx through the diaphragm to the stomach. It is a passageway that conducts food to the stomach
Mucosa
the innermost layer of the esophagus
Submucosa
is found just beneath the mucosa. It contains blood vessels, nerve endings, lymph nodules, and lymphatic vessels
Muscularis externa
muscle layer typically made up of an inner circular layer and an outer longitudinal layer of smooth muscle cells
Serosa
outermost layer of the esophagus wall
Visceral peritoneum
single layer of flat serous fluid-producing cells
Parietal peritonuneum
lines the abdominopelvic cavity by the way of a membrane expansion
Peritonitis
a condition of the peritoneum when the peritoneal membranes stick together around the infected site
Submucosal & Myenteric nerve plexus
these nerve fibers help regulate the mobility and secretory activity of GI tract organs
Cardioesophageal sphincter
is where food enters the stomach rom the esophagus
Pyloric sphincter
the pylorus is continuous with the small intestine
Rugae
when the stomach is empty, it collapses inward on itself, and its mucosa is thrown into large folds
Greater curvature
the convex lateral surface of the stomach
Lesser curvature
is the medial surface of the stomach
Lesser omentum
a double layer of peritoneum, extends from the liver to the lesser curvature
Greater omentum
another extension of the peritoneum, drapes downward and covers the abdominal organs
Intrinsic factor
a substance needed for the asorption of vitamin
B12 from the small intestine
Chief cells
produce protein-digesting enzymes, mostly pepsinogens and parietal cells produce corrosive hydrochloric acid, which make the stomach contents acidic and activates the enzymes
Enteroendocrine cells
produce local hormones, such as gastrin, that are important to the digestive activities of the stomach
Chyme
a heavy cream that is resembled after food has been processed in the stomach
Small Intestine
is the body's major digestive organ
Small intesine: three subdivsions
duodenum, jejunum, ileum
Ileocecal valve
The ileum meets, which joins the large and small intestines
Pancreatic ducts
are enzymes that are produced by the pancreas and then ducted into the duodenum where they complete the chemical breakdown of foods in the small intestine
Microvilli
tiny projections of the plasma membrane of the mucosa cells that give the cell surface a fuzzy appearance, sometimes referred to as the brush border
Villi
are fingerlike projections of the mucosa that give it a velvety appearence and feel, much like the soft nap of a towel
Lacteal
within each villus is arich capillary bed and a modified lymphatic capillary
Circular folds
also called plicae circulares are deep folds of both mucosa and submucosa layers. These folds do not disappear when food fills the small intestine
Large intestine
is much larger in diammeter than the small intestine but shorter in length
Large intestine: Subdivisions
cecum appendix, colon, rectum, anal canal