Unit 18 - Digestive System #2 Flashcards
1
Q
The ______ finishes the chemical digestion process and is responsible for absorbing most of the nutrients and fluids.
A
Small Intestine
2
Q
Ingested nutrients spend at least ______ in the small intestine as chemical digestion and absorption are completed.
A
12 hours
3
Q
The small intestine extends from the pylorus of the stomach to the cecum of the large intestine, and thus occupies a significant portion of the abdominal cavity.
A
True
4
Q
The “small intestine” (small bowel) is a coiled, thin-walled tube about 20 feet in length in a freshly dead person (it is much shorter in a living individual due to muscle tone).
A
True
5
Q
The small intestine receives its blood supply primarily from branches of the ______
A
superior mesenteric artery
6
Q
Venous drainage of the small intestine leads to the _____
A
hepatic portal vein
7
Q
The small intestine consists of three specific segments.
A
Duodenum, Jejunum, Ileum
8
Q
The duodenum, 10 inches long, is arched into a C-shape around the head of the pancreas and becomes continuous with the jejunum at the _____
A
“duodenojejunal flexure”
9
Q
Most of the duodenum is ____
A
retroperitoneal.
10
Q
Within the duodenum is the _____ through which bile from the liver and pancreatic juice from the pancreas enter the duodenum.
A
“major duodenal papilla”,
11
Q
The jejunum is the primary region within the small intestine for chemical digestion and nutrient absorption.
A
True
12
Q
It extends about 7.5 feet and makes up approximately two-fifths of the small intestine’s total length.
A
Jejunum
13
Q
It is intraperitoneal and suspended in the abdomen by the mesentery proper.
A
Jejunum and Ileum
14
Q
It is about 10.8 feet in length and forms approximately three-fifths of the small intestine.
A
Ileum
15
Q
Ileum’s distal end terminates at the _____, a sphincter that controls the entry of materials into the large intestine.
A
“ileocecal valve”
16
Q
The walls of the ileum have numerous aggregates of lymph nodes _____
A
(Peyer patches)
17
Q
Internally, the mucosal and submucosal tunics of the small intestine are thrown into _____
A
“circular folds”
18
Q
Circular folds, which can be seen with the naked eye, help increase the surface area through which nutrients can be absorbed.
b. In addition, the circular folds act like speed bumps to slow down the movement of chyme and ensure that it remains within the small intestine for maximal nutrient absorption.
A
True
19
Q
Circular folds are more numerous in the duodenum and jejunum, and least numerous in the ileum.
A
True
20
Q
When circular folds are viewed at the microscopic level, smaller, fingerlike projections of mucosa only, called _____, can be seen along their surface.
A
“villi”
These villi help increase further the surface area for absorption and secretion.
21
Q
Increasing the absorptive surface area even further are ______ along the free surface of the surface epithelial cells.
A
“microvilli”
22
Q
Each villus contains an arteriole and a venule, forming a rich capillary network, and a single lacteal.
A
True
23
Q
The capillaries absorb most nutrients.
The lacteal absorbs lipids and lipid-soluble vitamins, which are too large to be absorbed by the capillaries.
A
True
24
Q
Between some of the intestinal villi are invaginations of mucosa called ______ that produce mucus, digestive enzymes, and hormones that aid digestion.
A
“intestinal glands”
25
The proximal duodenum contains ______ which produce a viscous, alkaline mucus that protects the duodenum from the acidic chyme.
“submucosal glands”
26
a problem that often follows abdominal surgery.
Adhesions
27
forms a three-sided perimeter in the abdominal cavity around the centrally located small intestine.
Large Intestine
28
From its origin at the ileocecal junction to its termination at the anus, the large intestine has an approximate length of ____
5 feet.
29
It is called the “large” intestine because its diameter is greater than that of the small intestine.
True
30
On average, about _____ of digested material passes from the small intestine to the large intestine daily.
1 liter
31
The large intestine absorbs most of the water and electrolytes (salts) from the remaining digested material.
a. In so doing, the watery material that first enters the large intestine soon solidifies and becomes “feces”.
The large intestine also absorbs a very small percentage of the nutrients and fluids still remaining in the digested material.
True
32
The first region of the large intestine is a blind sac, called the ______, located in the right lower abdominal quadrant
“cecum”
33
This pouch extends inferiorly from the “ileocecal valve”, which represents the attachment of the distal end of the small intestine to the proximal end of the large
intestine.
Cecum
34
Projecting inferiorly from the posteromedial region of the cecum is the _____, a thin, hollow, fingerlike sac lined by lymphocyte-filled lymphatic nodules.
“vermiform appendix”
35
Inflammation of the appendix is called
appendicitis
36
Most cases of appendicitis occur because _____ obstructs the appendix. As the tissue in its wall becomes inflamed, the appendix swells, the blood supply is compromised, and bacteria may proliferate in the wall.
fecal matter
37
the appendix may burst and release its contents into the peritoneum, causing a massive and potentially deadly infection called _____
peritonitis
38
If the appendicitis fails to resolve, the inflamed appendix may be surgically removed in a procedure called an _____
appendectomy
39
Both the cecum and the appendix are ____ organs.
intraperitoneal
40
originates at the ileocecal valve and extends superiorly
| from the superior edge of the cecum along the right lateral border of the abdominal cavity.
“ascending colon”
41
The ascending colon is retroperitoneal, since its posterior wall directly adheres to the posterior abdominal wall, and only its anterior surface is covered with peritoneum.
True
42
As it approaches the inferior surface of the liver, the ascending colon makes a 90-
degree turn toward the left side of the abdominal cavity.
- This bend in the colon is called the _____
“right colonic flexure”
43
The ______ originates at the right colonic flexure and curves slightly anteriorly as it projects horizontally across the anterior region of the abdominal cavity.
“transverse colon”
It is intraperitoneal.
44
As the transverse colon approaches the spleen in the left upper quadrant of the abdomen, it makes a 90-degree turn inferiorly.
- The resulting bend in the colon is called the ______
“left colonic flexure” (“splenic flexure”).
45
The “descending colon” is ______ and found along the left side of the abdominal cavity.
It originates at the left colonic flexure and descends vertically until it terminates at the sigmoid colon.
retroperitoneal
46
The ______ originates at the “sigmoid flexure”, where the descending colon curves inferomedially into the pelvic cavity.
“sigmoid colon”
47
The sigmoid colon is intraperitoneal.
It terminates at the rectum.
True
48
A condition called _______ which may occur in the sigmoid colon because of the increased pressure (from constipation and/or gas) that exists in this region, can lead to small sacs or pouches developing in the intestinal wall.
“diverticulosis”
49
These diverticuli may become inflamed (“diverticulitis”)
True
50
The _____ is a retroperitoneal structure that connects to the sigmoid colon.
“rectum”
51
Three thick transverse folds of the rectum, called ______, ensure that fecal material is retained during the passing of gas
“rectal valves”
52
The _____ is a muscular tube that readily expands to store accumulated fecal material prior to defecation.
rectum
53
The terminal few centimeters of the large intestine are called the ______
“anal canal”.
54
The internal lining of the anal canal contains relatively thin longitudinal ridges, called ______, between which are small depressions termed _______.
“anal columns”, “anal sinuses”
55
As fecal material passes through the anal canal during defecation, pressure exerted on the anal sinuses causes their cells to release ______
mucin.
56
At the base of the anal canal are the ______, which close off the opening to the anal canal and relax (open) during defecation.
“internal anal sphincter” and the “external anal sphincter”
57
Unlike the small intestine, the large intestine lacks intestinal ______; however, it contains numerous intestinal glands that secrete mucus.
villi
58
The _____ act like elastic on a waistband to help bunch up the large intestine into many sacs, collectively called ______
teniae coli, “haustra”
59
Hanging off the external surface of the haustra are lobules of fat called _______
“epiploic appendages”.
60
second most common type of cancer in the United States
Colorectal cancer
61
_____ refers to a malignant growth anywhere along the intestine (colon and rectum)
colorectal cancer
62
Most colorectal cancers arise from _____, which are outgrowths from the colon mucosa.
polyps
63
_______, which checks for the presence of blood in the stools
fecal occult blood test
64
an endoscope is inserted into the rectum and sigmoid colon to check for polyps or cancer
sigmoidoscopy
65
The endoscope is inserted into the large intestine at least up to the right colic flexure of the colon, and sometimes as far proximally as the ileocecal valve
colonoscopy
66
an autoimmune disorder that affects up to 1% of the population in the United States. Gluten—a protein common in wheat, rye, and barley (but not rice or corn)—stimulates an immune response in affected individuals that damages the villi of the small intestine, which interferes with absorption.
Celiac disease
67
The term inflammatory bowel disease (IBD) applies to two autoimmune disorders,
Crohn disease and ulcerative colitis. In both of these disorders, selective regions of the intestine become inflamed
68
characterized by intermittent and relapsing episodes of intense abdominal cramping and diarrhea. Although any region of the GI tract may be involved, the distal ileum is the most frequently and severely affected site.
Crohn disease
69
ulcerative colitis involves only the large intestine
True
70
ulcerative colitis is associated with a profoundly increased risk of colon cancer.
True
71
characterized by abnormal function of the colon with symptoms of crampy abdominal pain, bloating, constipation, and/or diarrhea. It occurs in about one in every five people in the United States, and is more common in women than men.
irritable bowel syndrome (IBS)
72
lies in the right upper quadrant of the abdomen, immediately inferior to the diaphragm and it is the largest internal organ of the body.
Liver
73
The liver is covered by a connective tissue capsule.
True
74
The liver is separated into two major lobes by the _______ a peritoneal fold that secures the liver to the anterior abdominal wall.
falciform ligament
75
The liver’s connective tissue capsule branches through the liver and forms septa that partition the liver into thousands of small, polyhedral _______, which are the structural and functional units of the liver.
“hepatic lobules”
76
Within hepatic lobules are liver cells called _____
“hepatocytes”.
77
At the periphery of each lobule are several “portal triads”, composed of:
(a) Branches of the hepatic portal vein
(b) Branches of the hepatic artery
(c) Branches of the hepatic duct
78
At the center of each lobule is a ______ that drains the blood flow to the lobule.
(a) Central veins collect venous blood and merge throughout the liver to form numerous “hepatic veins” that eventually empty into the inferior vena cava.
“central vein”
79
The _____ carries blood from the capillaries of the GI tract, spleen,
and pancreas and provides about 75% of the blood volume to the liver.
- This blood is rich in nutrients and other absorbed substances but is relatively poor in oxygen.
“hepatic portal vein”
80
The ______, a branch of the celiac trunk, carries well-oxygenated blood and supplies the remaining blood to the liver.
“hepatic artery proper”
81
The numerous spokes of the wheel (hepatic lobule) are the _____, which are bordered by cords of hepatocytes.
“hepatic sinusoids”
82
_______ are thin-walled and leaky capillaries where venous and arterial blood are mixed and then flow slowly toward the central vein.
Hepatic sinusoids
83
The sinusoids are lined with stellate cells called _______ which phagocytize debris in blood as well as help break down and recycle components of aged erythrocytes and damaged or worn-out formed elements.
“reticuloendothelial cells”
84
Nutrients are absorbed from the sinusoids and enter the hepatocytes.
In the spaces between the spokes are cords of hepatocytes.
True
85
Sandwiched between each cord of hepatocytes is a small ______ which conduct bile from the hepatocytes to the hepatic duct in the portal triad.
“bile canaliculus”
86
Hepatocytes produce _____, a yellowish or greenish fluid that breaks down fats into small droplets to assist in their chemical digestion.
“bile”
Bile contains bile salts, bilirubin (breakdown product of blood), and cholesterol
87
(b) Hepatocytes detoxify drugs, metabolites, and poisons.
(c) Hepatocytes also store excess nutrients (typically as glycogen) and vitamins and
release them when they are needed.
(d) Hepatocytes synthesize blood plasma proteins.
- Albumin
- Globulins
- Clotting proteins
True
88
results when hepatocytes have been destroyed and are replaced by fibrous scar tissue. This scar tissue often surrounds isolated nodules of regenerating hepatocytes.
Cirrhosis of the Liver
89
The scar tissue also compresses both (1) the blood vessels, resulting in _____ (high blood pressure in the hepatic portal venous system
hepatic portal hypertension
90
a long-term inflammation of the liver that leads to necrosis of liver tissue
Chronic hepatitis
91
Most frequently, viral infections from either hepatitis B or hepatitis C produce chronic hepatitis
True
92
Advanced liver cirrhosis may have a variety of complications:
■Jaundice (yellowing of the skin and sclerae of the eyes) occurs when the liver’s ability to eliminate bilirubin is impaired.
■Edema (e-dē′mă), the accumulation of fluid in body tissues, is evident due to reduced formation and release of albumin.
■Ascites (ā-sī′tēz; fluid accumulation in the abdomen) develops because of decreased albumin production.
■Intense itching occurs when bile products are deposited in the skin.
■Toxins in the blood and brain accumulate because the liver cannot effectively process them.
■Hepatic portal hypertension (high blood pressure in the hepatic portal venous system) can lead to dilated veins of the inferior esophagus (esophageal varices).
93
End-stage liver cirrhosis can be treated only with a _____
liver transplant
94
Attached to the inferior surface of the liver, a saclike organ called the ______ concentrates bile produced by the liver and stores this concentrate until it is needed for digestion.
“gallbladder”
95
The ______ connects the gallbladder to the common bile duct.
“cystic duct”
96
High concentration of certain materials in the bile may lead to the eventual formation of ____
gallstones
97
The term _____ refers to the presence of gallstones in either the gallbladder or the biliary apparatus
cholelithiasis
98
Treatment consists of surgical removal of the gallbladder, called _____
cholecystectomy
99
Blood is brought to the gallbladder by a branch of the ______ and venous drainage eventually empties into the hepatic portal vein.
hepatic artery
100
The pancreas is referred to as a mixed gland because it exhibits both _____ functions.
endocrine and exocrine
101
The endocrine functions are performed by pancreatic islets ______ which produce insulin and glucagon.
(islets of Langerhans)
102
Exocrine activity of pancreas results in the secretion of digestive enzymes, collectively called _____ into the duodenum
“pancreatic juice”
103
The pancreas is a _______ organ that extends horizontally from the edge of the duodenum toward the left side of the abdominal cavity, touching the spleen.
retroperitoneal
104
The Pancreas:
1) It exhibits a wide “head” adjacent to the curvature of the duodenum
2) A central, elongated “body” projecting toward the left abdominal wall
3) A “tail” that tapers as it approaches the spleen
Yes
105
Pancreatic juice, in addition to digestive enzymes, contains _____ to help neutralize the acidic chime arriving in the duodenum from the stomach.
sodium bicarbonate
106
The majority of the pancreatic juice travels through the ________ towards the duodenum.
“main pancreatic duct”
107
The pancreas is supplied with arterial blood by a branch of the splenic artery and superior mesenteric artery while venous blood eventually drains into the hepatic portal vein.
Yes
108
The _____ is a network of thin ducts that carry bile from the liver and gallbladder to the duodenum.
“biliary apparatus”
109
The left and right lobes of the liver drain bile into the ______, respectively.
“left and right hepatic ducts”
110
The left and right hepatic ducts merge to form a single _____.
“common hepatic duct”
111
The ______ attaches to the common hepatic duct and carries bile to and from the gallbladder.
“cystic duct”
112
The union of the cystic duct and the common hepatic duct from the ______ that extends inferiorly to the duodenum.
“common bile duct”
113
The ______ is a posteriorly placed swelling on the duodenal wall where the common bile duct and main pancreatic duct merge and pierce the duodenal wall.
“hepatopancreatic ampulla”
114
Bile and pancreatic juice mix in the hepatopancreatic ampulla prior to emptying in
the duodenum via the ______
“major duodenal papilla”.
115
The exit of the hepatopancreatic ampulla into the duodenum is regulated by the
______ which controls the release of fluid from the hepatopancreatic ampulla and prevents the entrance of duodenal contents.
“sphincter of Oddi”
