Functional Development of the GI Flashcards
(105 cards)
1
Q
when does the gag reflex develop?
A
by 18 weeks
1
Q
Intrinsic factor is important for the absorption of______
A
Vitamin B-12
2
Q
Gastric EGF is present at _____ weeks and is needed for continued growth and development as well
A
18
2
Q
once the baby is born, the GI systen assumes which roles?
A
supplies energy
supplies nutrition
supplied fluid needs of the baby
2
Q
lower esophagus/reflux occurs because of
A
- incomplete development
- delayed maturaion of hormone receptors which decreases the response to gastrin
- improves as babies get older
2
Q
Protein digestion in the NN
swallows amniotic fluid, which is more alkaline,so there will be decreased gastric emptying
in order to break down/digest protein, we need HCL acid ad gastrin to increase secretionand is delayed initailly
A
gastrin and hcl will increase by 24 hrs after birth
we also see a little dip from 10-30 dus where they aren’t producing as much HCL so we hay see a feeding intolerane due to the change is acidity and alkalinity of the contents inthe stomach
2
Q
CHO metabolism
3 types of CHO
A
monosaccharide
disaccharide
polysaccarides
3
Q
Gastric Epidermal Growth factor
EGE
is also part of the functional evelopment of the_______
A
GI system
4
Q
Colonic Salvage
(lactose that is NOT absorbed in the small intestine is conserved this way
A
-bacterial fermentation of CHO and H gas and short term fatty acids which are absorbed by the colon
THis decreases the amount of CHO lost in the stool and fatty acids are producd and stored as a souce of energy/calories
in preemies, 2/3 id ingested lactose reaches the colon
5
Q
Chymotripsin is also secreted by the pancreas into the duodenum. It breaks the proteins down into
A
tyrosine, thryptophan, methalonine and lucine
6
Q
gag reflex is mature by _____
A
34 weeks
6
Q
Pancreatic protelytic hormones are
Digestion of protein is dependent upon all of these inclusing pepsin
A
Trypsin
chymotrypsin
carboxypolypeptidase
bicarbonate
6
Q
CHO metabolsim
MONO’s and Di’s are metabolozed______
A
QUickly
Polys take longer
cellulose cant be digested at all
6
Q
colonic salvage
A
is a protective mechanism
- even though there is a decreased lactase activity, lactase is important to breakdown lactose into glucose and galactose; so that’s important as well, so there is colonic salvage
- the sugar that is there causing bacterial fermentation causing fatty acids and fatty acids are used as a source of energy
7
Q
The processes needed for enteral nurition are in place by______
A
33-34 weeks
7
Q
NN esophageal motility
A
there is poor coordination of esophageal motility and swallowing initially because of:
- reduced tone, pressure and length of the lower esophageal sphincter which causes reflux
- reflux usually resoved by 6-12 months
-
7
Q
Human mild empties _____ faster than formula
A
2x
8
Q
failure of the fetus to swallow amniotic fluid is associated with?
A
GI obstruction
polyhydramnios in mom
9
Q
NORMAL PROTEIN CONCENTRATION SHOULD BE_____
A
2-4mg/kg/day
important that TPN trophamine levels don’t exceed that range
10
Q
GI system in the fetus is involved in removal of amniotic fluid;
the digestive and absorbtive functions are performed by what organ in the fetus?
A
placenta
10
Q
Digestion of protein is dependent on all of thses hormones, including pepsin
A
Trypsin
chymotrypsin
carboxypolypeptidase
becarbonate
11
Q
When does transport of fatty acids occur?
A
24 weeks
11
Q
what peptide is important for the the growth of the intesinal mucosa?
A
enteroglucagon
11
Q
the intestinal mucosal barrier is immature until 4-6 months and as a resut, antigens can be transported across the intestinal mucosa____
A
into the systemic circulation which increases the ris for infection and allergies
11
gastric capacity of a baby is \_\_\_\_
6 ml/kg
11
pretein digestion issues usually dont effect babies older than\_\_\_\_
26-28 weeks
11
salivary amylase-starts in the ______ and hydrolyzes starch
mouth
salivary gland fx
12
When are bile acids present in the intestine?
by 22 weeks
14
CHO metabolsim
disaccharides include
sucrose
lactose
maltose
15
when does the nutritive suck reflex develop?
32-34 weeks
17
it is important to have isomaltase when the enzymes are not avaiable to break down sucrose and
CHO metabolsim
glusose amylase is necessary to break down starch into disaccharide maltose (mouth)
19
Trypsinogin is secreted from the pancrease into the duodenum where is is broken down into\_\_\_\_\_\_
Trypsin
Trypsin is responsible for braking down proteins into amino acids Lysine and argenine
19
in NN
pepsinogen production is low, so less pepsin is available to breakdown protein
gastrinis present, but recepters are immature
21
When are bile acids present?
14-16 weeks
21
in breast fed infants, the absrption of macromolecules enhances passive immunity
23
intestinal motility begins to mature at \_\_\_-
30-32 weeks
- peristalis is associated with gastric motility
- peristalsis occurs in 3 phases
1-quiet
2-irregular cont
3-regula contr
timing of the phases occur over a 60-90" period between 29-33 weeks, the infant develops periods o quieness intersispersed with short bursts of activity
- more mature peristalsis is not seen until 32-34 weeks
- motilin-aminoacid peptide that s secreted by the mucosa of the small intestine and causes an increase in GI motility
24
suck-swallow coordination develops between \_\_\_\_
36-38 weeks
25
Sucking and swallowing
\*sucks early in utero
nutritive vs nonutritive sucking
26
CHO Metabolism
Monosaccharides include
sucrose
fructose
galactose
28
priming the GI tract by giving the baby how much enteral feeds?
0.5-1ml/kg/hr
it is important for the development of brush borders
enhances pancreatic function
increases gastric motility
reduces malabsorption
29
EGF also protects stomach from?\_\_\_\_\_
HCL acid production
31
GI function begins in fetal life and is complete after\_\_\_\_\_\_\_\_\_
Bith
32
What trimester does intestinal motility and peristalsis begin to occur?
3rd
34
Pepsin is needed for the digestion of proteins
Hormones to remember:
gastrin
Pepsin
Pepsinogen
35
37
antinatal steroids increase lung maturation as well as matruation of gi motlity
we usually dont see mec passing in preemies because of decreae peristalsis
38
all of these work together to metabolize protein
chyme, acid activates the pancreas to sevrete thee hormones
39
secretin
decreases motility of the GI tract
- increases pancreatic secretion of water and HCO3
- has an increasing affect as wll as a decresing affect
41
enteral feedings in a major stimulus for the production of GI hormones
getting trophic feeds intoa baby, especially with breast milk, is very helpful; it primes the gut and helps with maturation of the GI tract
early enteral feedings build up the mucosa
\*stimulates the development of crush borders enzymes as well as pancreatic function
\*enhances maturation
\*reduces distention, comiting and malabsorption
\*increases gut motility
\*decreases feeding intolerance
\*improves weight gain
\* inhances transition to oral feeds
\* decreases physiologic jaundice
\*decreases glucose intolernce
\*decreases sepsis
42
When does intestinal villi develope?
between 7-19 weeks ga
42
at what week(s) will the inant develop periods of gut quietness interdispersed with short bursts of activites called "clusters"
29-33 weeks
43
what two peptides help develop gut motor acticity?
motilin and neurotensin
44
Gastrin Does What?
\_\_\_\_ the secretion of HCL, Pepsinogen and intrinsic factor
increases
It is imoortant for gastric motility
46
Babies need some LACTOSE intake since lactose enhances\_\_\_\_\_\_
Ca+ absoortion
47
gastric inhibitory peptide
also secreted by the mucosal of the upper lining and in response to fat and CHO
-also lows gastric emptying into duodenum when the small intestine is over supplied with food
48
protein metabolism
a
49
intestinal surface area
- decreased absorption
- decreased villi causes a decreased brush border (immature sirface of the intestine decreases the absorption of nutrients)
decreased villi and epithelial cells decease host-defense mechanisms
50
The fetal liver is a hematopoietic organ amd in the 3rd trimester:
bone marrow erythropoiesisand increases metabolic activity
50
Enteral feedings will increase the production of GI hormones and \_\_\_\_\_\_
enhance maturation
52
sodium bicarb is also released to decrease acidity of chyme because
the enzymes function in a more alkaline environemnt
53
pepsinogen
is secreted by the ______ cells and _____ cells of the stomach
it is activated by \_\_\_\_\_
mucous and chief cells
pepsin
54
fetal distress
does what?
increases motilin
allows for passage of meconium in utero
56
metabolism if cho is acheived thr secreton of the # of digestive enzymes into the GO tract (especially the duodenum)
they enzymes attackthe CHO and convert them to simple sugars like glucose so that they can be absorbed by the bloodstream
58
gastric emptying in NN
- gastric motility and tone are decreased
- gastric emptying takes 2-6 hours
- gastric emptying is delayed because of:
delayed maturation of feedback hormonal control mechanisms & increased gastrin levels
- mucous in the stomach, especially 24 hrs after birth
- gastric emptying time varies with diet:
we see an increase in emptying time with CHO
-there is a decrease emptying time with fats
MCT empties faster that LCT
60
The disaccharide enzymes are very active after 27-28 weeks with the exception of \_\_\_\_\_\_\_, which does not reach mature levels until 36-40 weeks
LACTASE
61
An increase in the the GI hormone\_\_\_\_\_\_ accounts for passage of meconium in utero
Motilin
62
swallowing and sicking is seen in utero at how many weeks gestation?
10-14 weeks ga
63
what peptide is important for the the growth of the gastric mucosa and the pancreas?
Gastrin
64
swallowing is present at 28-30 weeks and is mature by
34 weeks ga
66
the stomach is an acidic environment and in order for nutrients to be absorbed, you need to have a more alkaline environment so secretin slows the gastric motility with increasing the panreases secretion of h=water and bicarb
this helps neutralize acid in the somach and with that the baby is better able to absorb nutrients
67
also stimulates pepsin segregation and released when there is acid and fat in the duodenum
68
The fetus, at 16 weeks, will swallo how much amniotic fluid?
2-6 ml per day
70
as CHO reach the colon, changes in the flora after abx/surgery/illness may alter the infants ability to conserve energy via the colonic salvage
lactose deficiences will resolve by 36-40 weeks
71
When does transport of glucose occur?
18 weeks
72
glucoamylase is an intestinal brush border enzyme and are 50-100% of adult values and rise after birth
lactase is active after 36 weeks
73
what are "clusters"?
immature waves of peristalsis
- more mature waves of peristalsis are not seen until 32-34 weeks
- motilin is associated with more mature waves of peristalsis and until about 32 weeks, the receptors for motilin are diminished
- receptors are funcional at 32 weeks, but not mature and there are fewer
(so premies has decreased peristalisis which is associaed with the inability to tolerate feedings)
74
The main souce of energy for the fetus is ______ from the mother
glucose
75
gastric inhibitory peptide is imortand for what?
glusose
75
Motilin
increases gastric motility; migratory motor complexes tht are 1st seen at 34 weeks
- migratory complex iniate peristalsis
- peristalsis in iniated by increase in gut motility
- in preemies, there is a decrease in peristalsis; don't usually see mec passage in preeemies
76
Sucrase and Maltase reach maximum levels at 32-34 weeks
lactase activity at 28-36 weeks is 30%
AVID at 36 weeks
-despite low lactase activity, preterm infants digest lactose effeciently
77
A full-term fetus will swallow how much amniotic fluid?
200-600 ml/day
78
The gut-regulating peptides help with the growth and development o the GI system iteslf
True
80
protein breakdown
enterpeptidase is 100% adult values
despite limitations, infants 26-28 weeks can absorb 85% of ingested protein
BUT cannot handle a high protein load of
\>5g/kg/day
provide enough, but not extra load
81
there is an increase for allergies and NEC because the baby absorbs larger intact proteins called
MACROMOLECULES
82
polysaccharides
CHO metabolism
include starches and cellulose (complex carb that can't be digested)
83
Protein Metabolism
GASTRIN
HCL
Increases the secretion of HCL acid, pepsinogen and intrinsic factor
- gastrin is released by the g-cells in the stomach
- hcl is secreted by the parietal cells of the stomach into the lumen where it extablishes and acid environment
- HCL is impotant for the activation of pepsinogin and inactivating pepsinogen and protecting from ingested microbes
84
enteral feedings helps to stimulate hormonal regulation via which peptides?
enterglucagon
gastrin
motilin
neurotensis
gastric inhibitory peptide
85
The GI anatomy is complete by how many weeks?
20
86
Transport of amino acids begins by\_\_\_\_
14 weeks ga
87
Gut regulating peptides are present by \_\_\_\_\_\_
24 weeks
89
Important for CHO metabolism
Brush borders have enzymes that change di's into mono's
lactase to lactose=glucose and galacrose
sucrase to sucrose=glucose and fructose
maltase to maltoseglucose and glucose
90
NON-Nutritive sucking is present by\_\_\_\_\_
24 weeks
with a rythmic motion by 33 weeks
and is mature by 37 weeks
92
Mammary amylase in human milk compensates for the decrease in pancreatic amylase
mammary amylase is highest in colustrum and gradually decrease after 6 weeks
93
we worry about babies with MAS because we know that stress has and iffect on the baby
espelling mec in utero
94
Gut regulating peptides that are present by 24 weeks include:
Gastrin
Motilin
Somatostatin (presnt by the end of the 1st trimester)
95
POSTNATAL development of the GI tract is
-affected by GA, genetics and diet and the iniatiation of
feedings by mouth
97
Meconium is seen in the GI tract by 10-12 weeks, but by \_\_\_\_\_it has actually moved into the colon
16
98
Peristalsis occurs in 3 phases in term babies. what are these 3 phases?
phase 1-Quiet phase
phase 2- irregular contractins occur
phase 3-regular contractions occur
there is a cycle of these phases over 60-90 minutes
99
disaccharide enzymes are preent by 9-10 weeks, but become very active after\_\_\_\_
27-28 weeks
100
Glucose absorption
is slower in preterm infants
- further reduced in SGA
- glucose absorbtion will increase by 2-3 weeks of age
- EPISODES of HYPOXIA and ISCHEMIA alters the intestinal absorbtion of glucose
101
where is secretin secreted?
by the mucosal lining of the duodenum in response of gastric gas juice emptying from the stmach thru the pylorus
102
there is an oral stimulation response by \_\_\_\_\_
as demonstrated by tongue protrusion, rooting and some suckling
13-15 weeks
103
Protein metabolism
Pancreatic protelytic hormones associated with protein metabolism:
Trypsin
Chymotrypsin
carboxypolipeptidase
Bicarbonate
104
inestinal motility
disorganized due to poor coordination of peristaltic waves an immature musculature
as a result:
there is a decreased ability to clear the gi gut
- poor absorption
- dehydration and electrolyte imbalances
- delayed meconium passage in pretermbabies
105
carboxypeptidase is also secreted from the pancreas and it works to develop ndividual
amino acids
