Chapter 23 (Lecture) Flashcards
all GI tract movement stops and the gut appears to be paralyzed
ileus
extreme dryness of the mouth
xerostomia
grinding or clenching of the teeth
bruxism
what is the effect of whole proteins being absorbed and seen by the immune systme
allergies
produces lysozyme
paneth
change in the epithelium of the lower esophagus from stratified squamous to a columnar epithelia
Barrett’s esophagus
common causes of malabsorption
- impaired nutrient absorption
- anything that interferes with the delivery of bile
- anything that interferes with the delivery of pancreatic juice
- severe bacterial infections
major site for nutrient absorption
small intestine
which structure of the small intestine is known as the brush border
microvilli
contains a large number of bacteria
large intestine
bacterial flora in the large intestine produce
- vitamin K
- B vitamins
- CO2
major site for nutrient absorption
small intestine
swallowing is hindered or prevented
achalasia
excess iron is deposited in the tissues, increasing skin pigmentation and the risk of hepatic cancer and liver cirrhosis
hemochromatosis
may result form excessively high levels of fat in the blood or excessive alcohol ingestion, but most acute cases arise from gallstones that block the bile duct
pancreatitis
abnormal accumulation of fluid within the peritoneal cavity
ascites
a noncontagious, periodic inflammation of the intestinal wall now understood to be an abnormal immune and inflammatory response to bacterial antigens
IBD
overeating followed by purging
bulemia
difficulty swallowing
dysphagia
brush border enzymes that act on disaccharides
sucrase, lactase, maltase
collects nutrient rich blood from the GI tract and delivers it to the liver
hepatic portal circulation
what structure of the small intestine contains the sphincter/valve that connects to the large intestine
ileum
inflammation of the intestine
enteritis
final product of carbohydrate digestion
monosaccharides
what causes the defection reflex
stretching of the rectal wall
first segment of the small intestine
duodenum
most water is absorbed in
small intestine
what type of breakdown would chewing food be classified as
mechanical breakdown
(segmentation, churning, mastication)
When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called
digestion
true or false:
All the chemical and mechanical phases of digestion from the mouth through the small intestine are directed toward changing food into forms that can pass through the epithelial cells lining the mucosa into the underlying blood and lymphatic vessels.
true
Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium?
mucosa
Which layer of the alimentary canal is responsible for segmentation and peristalsis?
muscularis externa
serous membrane that covers most digestive organs
visceral peritoneum
outermost layer of the walls of the intraperitoneal organs
serosa
sheets of peritoneal membrane that hold the digestive tract in place
mesentery
true or false:
the peritoneum is the most extensive serous membreane in the body
true
components of splanchnic circulation
- celiac artery
- hepatic portal vein
- superior mesenteric artery
nervous control of gastric secretion is provided by
- vagus nerve
- enteric plexus
Your patient has had a total gastrectomy (removal of the stomach). What potential problem are you MOST concerned about
anemia
The parietal cells of the stomach produce intrinsic factor, which permits the absorption of vitamin B12, a nutrient required for the maturation of red blood cells. Unless your patient receives vitamin B12 replacement therapy, he or she will develop pernicious anemia.
what stimuli inhibits salivation
being stressed or frightened
how many total permanent teeth should an adult have, assuming none have been lost or removed
32
impacted wisdom teeth is a problem that is never observed in children because
they lack third molar teeth
which structures of the body play a part in swallowing
mouth, pharynx, and esophagus all take part in swallowing
where does the involuntary portion of swallowing takes place in
the pharynx
the voluntary phase of swallolwing takes place within
the mouth
what structure is found in the stomach but nowhere else in the alimentary canal
an oblique muscle layer
produced in the stomach and contributes directly to the absorption of vitamin B12
intrinsic factor
begins as chyme enters the duodenum
intestinal phase of gastric secretion
true or false:
Chief cells secrete inactive pepsinogen in order to prevent acid erosion inside of the chief cells.
false
roles of stomach acid
- Stomach acid denatures proteins making the polypeptide chain more accessible to pepsin digestive enzymes.
- Low pH converts pepsinogen to its active form of pepsin, preventing the protease enzyme from digesting the cells that produce it.
- Many potentially harmful bacteria will be prevented entry to the small intestine by stomach acid.
true or false:
The major stimulus for production of intestinal fluid is distention or irritation of the intestinal mucosa by hypertonic or acidic chyme.
true
true or false:
most gastric ulcers are due to excessive production of HCl
false
which vessel delivers nutrient-rich blood to the liver from the digestive tract
hepatic portal vein
All blood from the digestive organs as well as the spleen is delivered to the liver in the hepatic portal vein before being returned to the general circulation.
secretion of the pancreas
- bicarbonate
- insulin
- nutrient digesting enzymes
why are protease enzymes secreted in active forms
The cells producing inactive enzymes are themselves protected from the enzymes until they are safely within the lumen of the GI tract.
functions of hepatocytes
- detoxify toxic chemicals
- store fat-soluble vitamins
- process nutrients
digestion and absorption of which type of molecule would be most affected if the liver were severely damaged
lipids
true or false:
the pancreas has both an endocrine and an exocrine function
true
what cells in the small intestine’s mucosa secrete mucus
goblet cells
first segment of the small intestine
duodenum
The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the structures accomplish this task?
villi and microvilli
what propels food residue over large areas of the colon three to four times a day
mass movement
as wastes navigate the large intestine, which features do they pass through in order
right colic (hepatic), left colic (splenic), and sigmoid flexures
functions of the large intestine
- absorption of water
- absorption of electrolytes
- synthesis of vitamins
can result if food passes too slowly through the large intestine
constipation
characteristics of the large intestine
- exhibits external muscular bands called teniae coli
- does not contain villi
- it has pocket-like sacs called haustra
true or false:
most nutrients are absorbed through the mucosa of the intestinal villi by active transport
true
which enzymes is/are responsible for the chemical breakdown of carbohydrates
amylase
carbohydrates are digested into
monosaccharides
You have just eaten a meal high in complex carbohydrates. Which enzyme will help to digest the meal?
amylase