Chapter 1: Nutrient Intake, Digestion, Absorption, Excretion Flashcards
(92 cards)
1
Q
CCK is stimulated by what
A
Protein, fat, acid
2
Q
Actions of CCK
A
stimulate pancreatic enzyme secretion, gallbladder contraction, growth of exocrine pancreas, INHIBITS gastric emptying **Decreases meal size by increasing satiety
3
Q
Serotonin (5-HT) - secretion is stimulated by?
A
Luminal contents including glucose and SCFAs, GI distention
4
Q
Serotonin increases or decreases intestinal motility
A
INCREASES
5
Q
Gastrin action on gut
A
promotes gastric emptying, stimulates gastric acid secretion and mucosal growth. Increased food volume leads to release of gastrin.
6
Q
Secretin
A
STIMULATED BY ACID. Stimulates pepsin, pancreatic, and biliary bicarbonate secretion, SLOWS gastric emptying and REDUCES gastric acid secretion.
7
Q
Fundus
A
uppermost portion of stomach
8
Q
Cardia of stomach
A
portion just distal to esophagus
9
Q
A
10
Q
antrum
A
lower 1/3 of stomach
11
Q
body of stomach begins at
A
horizontal plane of GE junction
12
Q
A relaxed stomach can accommodate a volume of
A
.8 to 1.5 liters
13
Q
average half-emptying time of water or isotonic saline (NS)
A
12 mins (range 10 to 65 mins)
14
Q
Which two duodenal osmoreceptors regulate liquid emptying
A
secretin and VIP
15
Q
average half emptying time of solids
A
2 hours (range 45-110 mins)
16
Q
When the swallowing mechanism is bypassed, the rate of gastric emptying is….
A
FASTER. Ie. NG tube feedings result in faster gastric emptying
17
Q
Average time for chyme to travel from the pylorus to the ileocecal valve
A
3-5 hours
18
Q
What hormones inhibit peristalsis
A
Secretin and glucagon
19
Q
Volume of chyme that empties into the cecum per day
A
1.5 to 2 L
20
Q
Luminal contents become more solid as they move through what part of the colon
A
the transverse to the descending
21
Q
Stool from ascending colostomy like to be more liquid or solid
A
More liquid
22
Q
transit time of chyme from the ileocecal valve through the colon
A
8 to 15 hours
23
Q
Motility of what part of the GI tract is the last to recover following GI surgery
A
Colon motility
24
Q
how long do the stomach and colon require after surgery for return of peristalsis and bowel function
A
48 hrs
25
how long for peristalsis to return after surgery in the small bowel
24 hours
26
anticholinergics
reduce gut motility and can worsen constipation and increase risk of ileus. They include: diphenhydramine (Benadryl), scopolamine, glycopyrrolate, oxybutynin, ipratropium, and tiotropiu
27
chronic intestinal pseudoobstruction (CIP)
motility disorder of peristalsis, most commonly affecting small bowel. Treatment involves intermittent NG suction, rectal tubes, or endoscopy.
28
colonic pseudo obstructions can occur as a complication of
narcotics, bed rest, disease
29
nutritional management of CIP
palliation of sx including N/V, provision of IV hydration or PN, nocturnal cyclic EN when possible
Recommend small freq meals low in fat and fiber
Emphasize liquid forms of energy and protein
Recommend daily MVI
Elemental diet with MCTs may be considered if pt does not tolerate polymeric nutrients
30
What vitamins should be recommended with SIBO
fat soluble and B12 vitamins
31
diarrhea definition
2-3 liquid stools or more than 250 mL liquid stool per day
32
PMC
pseudomembranous colitis. refers to intestinal inflammation accompanied by presence of pseudomembranes on intestinal mucosa. Most cases involve the colon, ALL cases are related to c.diff infection. Sx include: diarrhea, abdominal pain, fever, elevated WBC, hx of recent use of abx. PMC can lead to colitis, toxic megacolon, subsequent perforation.
33
ORS recipe
2.6 g Nacl, 13.5 g anhydrous glucose, 1.5 g Kcl, 2.9g trisodium citrate, 1 Liter water
34
How do SCFAs help to control diarrhea
by stimulating uptake of water and electrolytes by colonocytes, binding bile acids, and slowing gastric emptying
35
Gastroparesis dietary recs
small/freq meals
drinking fluids with meals
low fat/low fiber
obtain good glycemic control
post-pyloric feeds when necessary
36
constipation is defined as
fewer than 3 bowel movements per week, hard stools, excessive straining, prolonged time spent on toilet, sense of incomplete evacuation, abdominal discomfort, bloating
37
what conditions are associated with constipation
diabetes, hypothyroidism, hypercalcemia, dehydration, neurologic disorders, anorectal disease, collagen vascular/muscular diseases
38
constipation treatment
dietary: 25-30g fiber per day (gradual increase), 1.5-2 L per day of fluid
first line medication treatment: (psyllium, bran methylcellulose, polycarbophil), stool softeners, and osmotic laxatives, lactulose, sorbitol, and magnesium salts)
second line meds: stimulants (senna/docusate, basacodyl/docusate (dulcolax), or casanthranol/docusate) and lubricants
** if severe: osmotic laxatives can be combined with suppositories or enemas to loosen stools from a proximal and distal approach
39
vagotomy and bypass or destruction of pylorus leads to
dumping syndrome
40
early vs late dumping syndrome
early: 30-60 mins of eating
late: 2-3 hours of eating
41
average daily saliva secretion
1 to 1.5 L
42
Does obesity increase or decrease salivation
Decrease via increased leptin and decreased ghrelin
43
average gastric secretions per day
2.5 L
44
parietal cells in stomach location and role
secrete Hcl and intrinsic factor, Located in body and fundus of stomach
45
pH of gastric acid
0.8
46
Biochemical stimulants for acid secretion
gastrin, histamine via H2 receptors, acetylcholine released by parasympathetic stimulation
47
What two substances stimulate gastrin and acid production
caffeine and alcohol
48
cephalic phase of digestion
causes vagus nerve to release acetylcholine which stimulates the ECL cells and parietal cells. Accounts for 30% of the volume of acid secretion.
49
gastric phase of digestion
begins when food arrives in the stomach. amino acids and peptides stimulate the G cells in the antrum to produce gastrin, which enters the general circulation and stimulates parietal cells. Gastric distension also leads to acid secretion. Accounts for 60% of the volume of acid secreted.
50
intestinal phase of digestion
10% of gastric acid secretion. food in the duodenum continues to stimulate small amounts of gastric secretions
51
Presence of CHO, fat, PROT in duodenum ____ gastric acid, pepsin secretion, and gastric motility
inhibits
52
GIP, VIP, Somatostatin and Secretin all have what affect on gastric acid secretion
INHIBITS *****
The Secret Service STOPS all Acid Doers at the GIP VIP Bar
53
bilirubin
waste product of the breakdown of hemoglobin
54
what would cause white stools?
biliary obstruction preventing bile acids from entering the colon
55
how much bile is secreted per day
500 mL
56
bile salt reabsorption occurs where
terminal ileum
57
enterohepatic circulation
process where reabsorbed bile salts and bile pigments are transported to the liver via the portal vein and then are reexcreted in the bile
58
Bile production is stimulated by
vagus nerve nad secretin
59
Bile salts
METABOLITES OF CHOLESTEROL
sodium and potassium salts of bile acids
60
volume of pancreatic juice secreted daily into duodenum
1.5 L
61
sphincter of oddi
The sphincter of Oddi is a muscular valve that controls the flow of bile and pancreatic juices from the liver and pancreas into the duodenum
62
In the fasting state without any EN -- gastric secretions can amount to
500 to 1000 mL/d
63
In the fasting state without any EN -- biliary and pancreatic secretions can amount to
1-2 L/d
64
ligament of treitz
where the duodenum becomes the jejunum
65
length of small bowel
350-600 cm
66
when ileal pressure increases.. the ileocecal valve
opens
67
when colonic pressure increases... the ileocecal valve
shuts
68
How many liters of fluid enter the small intestine each day
9 liters (2 liters from dietary sources and 7 liters from GI secretions)
1-2 liters enter the colon
200 mL stool is lost daily
69
70
Thiamine is absorbed where
Jejunum and ileum
71
Why can low thiamine lead to lactic acidosis
Thiamjne is crucial for breaking down glucose and turning it into energy (glycolysis).. it's a cofactor needed in aerobic metabolism (glycolysis) to convert pyruvate to acetyl-CoA. When pyruvste cannot enter the TCA cycle, it is then converted to lactate
72
Average time it takes for chyme to travel from pylorus to ileocecal valve
3-5 hours
73
Average half emptying time of water or isotonic saline
12 mins
74
Average half emptying time of solids
45-110 mins
75
When swallowing mechanism is bypassed, gastric emptying is
Fasyer
76
Relaxed stomach can accommodate a volume of
0.8 - 1.5 liters
77
Volume of chyme that empties into cecum
1.5-2 liters per day
78
How many hours for chime to move from the ileocecal valve through the colon
8-15 hours
79
High osmolality ______ gastric emptying
Slows
80
Low pH ______ gastric emptying
Slows
81
CCK ____ gastric motility and ______ small intestinal motility
Decreases and stimulates
CCK = calms the stomach kickstarts the small intestine
82
IVF for SBO
Isotonic ( NS OR LR)
83
Inflammation has what effect on the gut
Reduce smooth muscle activity causing a shut down of peristalsis = increased ileus risk
84
Which electrolyte imbalances contribute to DKA
Hypomagnesemia and hypokalemia via decreased smooth muscle contractions
85
What type of EN to prevent or manage ileus post op.
Post pyloric can be initiated as soon as as 6 hours after surgery
86
Olgivie syndrome
colonic CIP
87
Treatment of colonic CIP
Palliation of sx such as antiemetics and pro kinetics
Nocturnal cyclic EN
If oral diet: small drew meals los in fat and fiber, emphasize liquid forms of energy and protein
88
What vitamins should you assess in SIBO
Fat soluble and b12
89
What is lost in diarrhea
Sodium potassium and water
90
PMC
Psuedomembranous colitis
Treatment: caffeine free CLD, advance to low fat low fiber low lactose to address transient nutrient intolerances from loss of brush border enzymes related to diarrhea
91
Diagnostic criteria for gastriparesis
>75 percent retained after 2 hours and >25 percent retained after 4 hours
92
What medication can be used in severe gastoparesis refractory to dietary treatment
Octreotide (somatostatin analog)
