NU 578
Unit 6 Study Guide
Key Concepts & Exam Review
University of South Alabama.
This document provides a focused
study guide
It summarizes key concepts, lecture highlights, and
exam-relevant material to support efficient last-
minute review. The guide is structured to help students reinforce
understanding, identify weak areas, and prepare confidently for
the assessment.
,Exam 6 Study Guide
1. ANATOMY AND FUNCTION OF THE GI SYSTEM COMPONENTS;
NORMAL INTESTINAL FLORA. (pp.1393-97, 1400, 1409; key search
term: “except for chewing”)
The digestive system breaks down ingested food, prepares it for uptake by the
body’s cells, provides body water, and eliminates wastes.
The GI tract consists of
Enteric nervous system within GI tract controlled by local and autonomic
nervous system—3 nerve plexus:
o Submucosal plexus: located muscularis
o Myenteric plexus: between the inner circular and outer
longitudinal muscle layers in the muscularis
o Subserosal plexus: beneath the serosa
o The enteric plexus neurons regulate motility reflexes, blood flow,
absorption, secretions, and immune responses.
is reservoir for chewing and mixing food with saliva. 3 pairs salivary glands
(submandibular, sublingual, and parotid). Saliva consist mostly of water that
contains mucus, sodium, bicarb, chloride, potassium, and salivary a-amylase
(ptyalin), an enzyme that initiates carb digestion in the mouth and stomach.
is a hollow muscular tube that controls swallowing substances from oropharynx
to stomach. Each end of the esophagus has a sphincter: cricopharyngeal muscle
and cardiac sphincter.
is a hollow muscular organ that stores food during eating, secretes digestive
juices, mixes food with juices, and propels partially digested food (chyme) into
the duodenum of small intestine.
intestine is about 5 to 6 m long and is functionally divided into three
segments: the duodenum, jejunum, and ileum.
: essential role in mixing food with digestive juices from the liver and pancreas.
and ileum facilitate intestinal motility and support blood vessels, nerves, and
lymphatics.
is the serous membrane surrounding the organs of the abdomen and lining the
abdominopelvic cavity.
Large is approximately 1.5 m long and consists of the cecum, appendix, colon,
rectum, and anal canal.
is a pouch that receives chyme from the ileum. Attached to the cecum is
the vermiform appendix, has little or no physiologic function.
o From the cecum, chyme enters the colon, four-parts that descends to the
anal canal: ascending colon, transverse colon, descending colon, and
sigmoid colon. Most of the water is absorbed in the colon by diffusion and
active transport.
o By the time the fecal mass enters the sigmoid colon, the mass consists
entirely of wastes and is called the feces. The movement of feces into the
sigmoid colon and rectum stimulates the defecation reflex
(rectosphincteric reflex).
o Defecation is facilitated by squatting or sitting because these positions
straighten the angle between the rectum and anal canal and increase the
efficiency of straining.
Bacteria from stomach to distal colon Stomach is relatively sterile due to
acid production. Bile acid secretion, intestinal motility, and antibody production
, suppress bacterial growth in the duodenum, and in the duodenum and jejunum
there is a low concentration of aerobes: streptococci, lactobacilli, staphylococci,
enterobacteria, and Bacteroides. Anaerobes are found distal to ileocecal valve
and consists 95% of fecal flora and 1/3 of the solid bulk of feces: Bacteroides,
clostridia, anaerobic lactobacilli, and coliforms are the most common
microorganisms from the ileum to the cecum.
Liver, gallbladder, and exocrine pancreas all secrete substances necessary
for the digestion of chyme. These secretions are delivered to the duodenum
through ducts. The liver produces bile, which contains salts necessary for fat
digestion and absorption. Between meals bile is stored in the gallbladder.
The exocrine pancreas produces enzymes needed for the complete digestion of
carbohydrates, proteins, and fats. The exocrine pancreas also produces an
alkaline fluid that neutralizes chyme, creating a duodenal pH that supports
enzymatic action. The liver receives nutrients absorbed by the small intestine
and metabolizes or synthesizes these nutrients into forms that can be absorbed
by the body’s cells. It then releases the nutrients into the bloodstream or stores
them for later use.
1. Know disorders of GI tract and accessory organs of digestion: pathophysiology,
etiology, prevention, clinical manifestations, diagnostics, treatment and
complications
Disorders of :
o difficulty swallowing and can result from mechanical obstruction of
esophagus (within the walls of esophagus or outside esophageal lumen—
narrow esophagus) or functional disorder impairing esophageal motility
(neural or muscular disorders).
o Gastroesophageal Reflux Disease: the reflux of acid and pepsin from
the stomach to the esophagus that causes esophagitis.
o Hiatal Hernia: the protrusion (herniation) of the upper part of the
stomach through the diaphragm and into the thorax. There are four
types:
1. Sliding (Type I)- most common; portion of stomach moves into thoracic cavity
through esophageal hiatus
2. Paraoesophageal (Type II)- 30-60% of stomach moves into thorax
3. Mixed (Type III)- include elements of types I and II
4. Type IV- the entire stomach and other abdominal organs slide into the thorax.
o Pyloric Obstruction (gastric outlet obstruction): narrowing or blocking
of the opening between the stomach and the duodenum.
o Intestinal Obstruction and Ileus: intestinal obstruction can be caused
by any condition that prevents the normal flow of chyme through the
intestinal lumen or failure of normal intestinal motility in the absence of
an obstructing lesion (ileus). The small intestine is more commonly
obstructed because of its narrower lumen. Simple obstruction is
mechanical blockage of the lumen by a lesion and is the most common
type of intestinal obstruction. Paralytic ileus, or functional obstruction, is
a failure of motility after gastrointestinal or abdominal surgery.
Anesthetic agents, local inflammatory reactions, use of opioid analgesia,
and hyperactivity of the sympathetic nervous system contribute to
postoperative ileus
Unit 6 Study Guide
Key Concepts & Exam Review
University of South Alabama.
This document provides a focused
study guide
It summarizes key concepts, lecture highlights, and
exam-relevant material to support efficient last-
minute review. The guide is structured to help students reinforce
understanding, identify weak areas, and prepare confidently for
the assessment.
,Exam 6 Study Guide
1. ANATOMY AND FUNCTION OF THE GI SYSTEM COMPONENTS;
NORMAL INTESTINAL FLORA. (pp.1393-97, 1400, 1409; key search
term: “except for chewing”)
The digestive system breaks down ingested food, prepares it for uptake by the
body’s cells, provides body water, and eliminates wastes.
The GI tract consists of
Enteric nervous system within GI tract controlled by local and autonomic
nervous system—3 nerve plexus:
o Submucosal plexus: located muscularis
o Myenteric plexus: between the inner circular and outer
longitudinal muscle layers in the muscularis
o Subserosal plexus: beneath the serosa
o The enteric plexus neurons regulate motility reflexes, blood flow,
absorption, secretions, and immune responses.
is reservoir for chewing and mixing food with saliva. 3 pairs salivary glands
(submandibular, sublingual, and parotid). Saliva consist mostly of water that
contains mucus, sodium, bicarb, chloride, potassium, and salivary a-amylase
(ptyalin), an enzyme that initiates carb digestion in the mouth and stomach.
is a hollow muscular tube that controls swallowing substances from oropharynx
to stomach. Each end of the esophagus has a sphincter: cricopharyngeal muscle
and cardiac sphincter.
is a hollow muscular organ that stores food during eating, secretes digestive
juices, mixes food with juices, and propels partially digested food (chyme) into
the duodenum of small intestine.
intestine is about 5 to 6 m long and is functionally divided into three
segments: the duodenum, jejunum, and ileum.
: essential role in mixing food with digestive juices from the liver and pancreas.
and ileum facilitate intestinal motility and support blood vessels, nerves, and
lymphatics.
is the serous membrane surrounding the organs of the abdomen and lining the
abdominopelvic cavity.
Large is approximately 1.5 m long and consists of the cecum, appendix, colon,
rectum, and anal canal.
is a pouch that receives chyme from the ileum. Attached to the cecum is
the vermiform appendix, has little or no physiologic function.
o From the cecum, chyme enters the colon, four-parts that descends to the
anal canal: ascending colon, transverse colon, descending colon, and
sigmoid colon. Most of the water is absorbed in the colon by diffusion and
active transport.
o By the time the fecal mass enters the sigmoid colon, the mass consists
entirely of wastes and is called the feces. The movement of feces into the
sigmoid colon and rectum stimulates the defecation reflex
(rectosphincteric reflex).
o Defecation is facilitated by squatting or sitting because these positions
straighten the angle between the rectum and anal canal and increase the
efficiency of straining.
Bacteria from stomach to distal colon Stomach is relatively sterile due to
acid production. Bile acid secretion, intestinal motility, and antibody production
, suppress bacterial growth in the duodenum, and in the duodenum and jejunum
there is a low concentration of aerobes: streptococci, lactobacilli, staphylococci,
enterobacteria, and Bacteroides. Anaerobes are found distal to ileocecal valve
and consists 95% of fecal flora and 1/3 of the solid bulk of feces: Bacteroides,
clostridia, anaerobic lactobacilli, and coliforms are the most common
microorganisms from the ileum to the cecum.
Liver, gallbladder, and exocrine pancreas all secrete substances necessary
for the digestion of chyme. These secretions are delivered to the duodenum
through ducts. The liver produces bile, which contains salts necessary for fat
digestion and absorption. Between meals bile is stored in the gallbladder.
The exocrine pancreas produces enzymes needed for the complete digestion of
carbohydrates, proteins, and fats. The exocrine pancreas also produces an
alkaline fluid that neutralizes chyme, creating a duodenal pH that supports
enzymatic action. The liver receives nutrients absorbed by the small intestine
and metabolizes or synthesizes these nutrients into forms that can be absorbed
by the body’s cells. It then releases the nutrients into the bloodstream or stores
them for later use.
1. Know disorders of GI tract and accessory organs of digestion: pathophysiology,
etiology, prevention, clinical manifestations, diagnostics, treatment and
complications
Disorders of :
o difficulty swallowing and can result from mechanical obstruction of
esophagus (within the walls of esophagus or outside esophageal lumen—
narrow esophagus) or functional disorder impairing esophageal motility
(neural or muscular disorders).
o Gastroesophageal Reflux Disease: the reflux of acid and pepsin from
the stomach to the esophagus that causes esophagitis.
o Hiatal Hernia: the protrusion (herniation) of the upper part of the
stomach through the diaphragm and into the thorax. There are four
types:
1. Sliding (Type I)- most common; portion of stomach moves into thoracic cavity
through esophageal hiatus
2. Paraoesophageal (Type II)- 30-60% of stomach moves into thorax
3. Mixed (Type III)- include elements of types I and II
4. Type IV- the entire stomach and other abdominal organs slide into the thorax.
o Pyloric Obstruction (gastric outlet obstruction): narrowing or blocking
of the opening between the stomach and the duodenum.
o Intestinal Obstruction and Ileus: intestinal obstruction can be caused
by any condition that prevents the normal flow of chyme through the
intestinal lumen or failure of normal intestinal motility in the absence of
an obstructing lesion (ileus). The small intestine is more commonly
obstructed because of its narrower lumen. Simple obstruction is
mechanical blockage of the lumen by a lesion and is the most common
type of intestinal obstruction. Paralytic ileus, or functional obstruction, is
a failure of motility after gastrointestinal or abdominal surgery.
Anesthetic agents, local inflammatory reactions, use of opioid analgesia,
and hyperactivity of the sympathetic nervous system contribute to
postoperative ileus
