BIOS 256 Exam 1 Study Guide
1. Gastrointestinal tract: A continuous tube from the opening of the mouth all the way to the anus
2. Organs of the GI tract: Mouth, most of the pharynx, esophagus, stomach, small intestine and large
intestine
3. Accessory digestive organs: Teeth, tongue, salivary glands, liver, gallbladder, and pancreas
4. Functions of the digestive system: Ingestion, secretion, motility, digestion, absorption, and defe-
cation
5. Layers of the GI tract (Deep to superficial): Mucosa, submucosa, muscularis externa, and serosa
6. Mucosa: Mucous membrane composed of a layer of epithelium, a layer of areolar connective tissue called the
lamina propria, and a thin layer of smooth muscle called the muscularis mucosae
7. Specialized cells of the mucosa: Enteroendocrine cells that secrete hormones, MALT cells for immune
defense.
,8. Submucosa: Esophageal Gland - Areolar connective tissue that binds the mucosa to the muscularis and
contains glands, blood, lymphatic vessels and tissue, and the submucosal plexus (ENS)
9. Muscularis Externa: Skeletal muscle layer in the mouth, pharynx, superior and middle parts of the
esophagus and the external anal sphincter, contains the myenteric plexus (ENS), contains 2 layers: Inner Circular Layer
and Outer Longitudal Layer
10. Serosa: A serous membrane composed of areolar connective tissue and simple squamous epithelium, forms a
portion of the peritoneum (visceral peritoneum)
11. Adventitia: The single outer layer of areolar connective tissue that surrounds the esophagus (lacks a serosa)
12. Myenteric plexus (ENS): Motor neurons control the longitudinal and circular smooth muscle layers of
the muscularis externa, controls GI tract motility or the frequency and strength of contractions
13. Submucosal plexus (ENS): Found in the submucosa, control the secretions of the organs in the GI tract
14. Stimulation of the sympathetic nerves in the GI tract cause...: A decrease in GI tract
secretion and motility by inhibiting the ENS neurons (fight or flight)
15. Stimulation of the parasympathetic nerves in the GI tract cause...: An increase in
, GI secretion and motility by increasing activity of the ENS neurons (rest and digest)
16. The Gastrointestinal Reflex pathways regulate: GI secretion and motility in response to
stimuli present in the GI tract lumen
1. Gastrointestinal tract: A continuous tube from the opening of the mouth all the way to the anus
2. Organs of the GI tract: Mouth, most of the pharynx, esophagus, stomach, small intestine and large
intestine
3. Accessory digestive organs: Teeth, tongue, salivary glands, liver, gallbladder, and pancreas
4. Functions of the digestive system: Ingestion, secretion, motility, digestion, absorption, and defe-
cation
5. Layers of the GI tract (Deep to superficial): Mucosa, submucosa, muscularis externa, and serosa
6. Mucosa: Mucous membrane composed of a layer of epithelium, a layer of areolar connective tissue called the
lamina propria, and a thin layer of smooth muscle called the muscularis mucosae
7. Specialized cells of the mucosa: Enteroendocrine cells that secrete hormones, MALT cells for immune
defense.
,8. Submucosa: Esophageal Gland - Areolar connective tissue that binds the mucosa to the muscularis and
contains glands, blood, lymphatic vessels and tissue, and the submucosal plexus (ENS)
9. Muscularis Externa: Skeletal muscle layer in the mouth, pharynx, superior and middle parts of the
esophagus and the external anal sphincter, contains the myenteric plexus (ENS), contains 2 layers: Inner Circular Layer
and Outer Longitudal Layer
10. Serosa: A serous membrane composed of areolar connective tissue and simple squamous epithelium, forms a
portion of the peritoneum (visceral peritoneum)
11. Adventitia: The single outer layer of areolar connective tissue that surrounds the esophagus (lacks a serosa)
12. Myenteric plexus (ENS): Motor neurons control the longitudinal and circular smooth muscle layers of
the muscularis externa, controls GI tract motility or the frequency and strength of contractions
13. Submucosal plexus (ENS): Found in the submucosa, control the secretions of the organs in the GI tract
14. Stimulation of the sympathetic nerves in the GI tract cause...: A decrease in GI tract
secretion and motility by inhibiting the ENS neurons (fight or flight)
15. Stimulation of the parasympathetic nerves in the GI tract cause...: An increase in
, GI secretion and motility by increasing activity of the ENS neurons (rest and digest)
16. The Gastrointestinal Reflex pathways regulate: GI secretion and motility in response to
stimuli present in the GI tract lumen
