Development of the GI function and nutritional needs in early life

Question 1

what is the blood supply of the

• foregut
• midgut
• handout

Answer 1

Foregut – supplied by the celiac artery
Midgut the superior mesenteric artery
Hindgut – interior mesenteric artery

Question 2

what are some foregut developmental abnormalities

Answer 2

• oesophageal atresia
• tracheo-oesophageal fistulae
• congenital hiatus hernia
• pyloric stenosis
• duodenal atreasia

Question 3

what is oesophageal atresia

Answer 3

• this is when there is a blockage in the oesophagus, this means that they will have difficulty swallowing

Question 4

how does oesophagus and respiratory tract form

Answer 4

the oesophagus and the respiratory tract start of combined and then they split of into a septum into two different tubes

Question 5

what can develop if the trachea does not separate from the oesophagus

Answer 5

• failure of separation so there is tubes
• atresia of the oesophagus
• atresia of the oesophagus with fistula - this means that the oesophagus just goes into the trachea

Question 6

why do babies get reflux

Answer 6

• can have reflux due to being overfeed

- mothers can over feed the baby because it cry so they get too much milk

Question 7

what causes GORD

Answer 7

• lower oesophageal sphincter is relaxed and it hasn’t tightened yet

Question 8

how does GORD increase or decrease through the infants life

Answer 8

• benign and very common
• 50% - 1-3months
• 5% - 12 months
• very few have 24 months
• they just grow out of it as the lOS develops over a few months

Question 9

what is duodenal atresia

Answer 9

• this is a blockage in the duodenum

- will present as bloating and vomitting but it will take longer to present than if the oesophagus is relaxed

Question 10

what is a diaphragmatic hernia

Answer 10

• this is when the diaphragm has a hole in it, the intestines therefore go into the chest
• this can lead to the lungs being underdeveloped

Question 11

describer how the midgut grows

Answer 11

• around 10-11 weeks the midgut grows very rapidly so there isn’t room for the foetus abdomen with it
• therefore it goes into the umblicious
• at 11-12 weeks it rotates and comes back into the abdomen
• then the cecum develops

Question 12

when is the position of the abdominal organs completed

Answer 12

• it is completed as the ascending colon attaches to the posterior abdominal wall

Question 13

what are some midgut developmental abnormaities

Answer 13

• Jejunal atresia – this will present as throwing up but with bile
• Malrotation - as it comes back into the abdomen the intestines are still rotating so the appendix is up against the liver, the duodenum does not go across the midline and it goes straight down instead of going across the midline
• Meckel’s diverticulum
• Omphalocoele
• Gastrochisis

Question 14

what happens in midgut volvulus with ischemai

Answer 14

• The bowel has twisted probably around the SMC so you end up with necrotic gangiorus gut
• The surgeons will undue it and wait to see if the blood supply is there and will get a better colour
• If not they will have to rescet it – lead to intestinal failure

Question 15

what is the duodenum-jejunum junction anchored by

Answer 15

• it is anchored by the ligament of tretiz

Question 16

when does intestinal malrotation occur

Answer 16

• it occurs when there is failure of the normal rotation and fixation

Question 17

how do you treat ompehalcel or gastroshesis

Answer 17

• You get a mesh which you stick to the skin around the bowel and you then pull it in
• Don’t rush it as if you have a whole load of bowl the first thing will happen is they will stop breathing as diaphragm cant cope with intestines
• Once it is back in then you stitch up the hole

Question 18

what does persistence of the vitelline duct give rise to

Answer 18

Meckels diverticulum

Question 19

what happens in meckels diverticulum

Answer 19

• the vitelline duct is normally is obliterated and looses its connection to the midgut loop before the loop returns to the abdominal cavity
• persistence of the proximal part of the duct forms mockers diverticulum
• the diverticulum is attached to the terminal ileum near the ileo-caecal junction and represents the apex of the midgut loop
• ectopic gastric mucosa or pancreatic tissue may be present in the diverticulum

Question 20

how do you identify ectopic gastric mucosa in meckel’s diverticulum

Answer 20

• uses nuclear medicine scan

- shows a spot where there should not be a spot

Question 21

what are some handgun abnormalities

Answer 21

anorectal abnormalities

Question 22

what is a imperforate anus

Answer 22

• Low imperforate anus
• high imperforate anus
• Not have a hole in the anus
  Picked up at birth

Question 23

what do neural crest cells give rise to

Answer 23

enteric ganglia

Question 24

describe how neurocrest cells develop

Answer 24

• a subpopulation of neural crest cells migrate through the embryo from the lateral edges of the neural plate and give rise to the enteric ganglia
• neural crest cells from the occiptocervical region populate the entire gut
• neural crest cells from the sacral region populate the distal gut

Question 25

what is hirschprungs disease

Answer 25

• this is failure of neural crest cells to migrate to the correct location and this leads to absence of ganglion cells
• absence of inhibitor innervation results in tonic contraction and colonic obstruction

Question 26

when do vili develop

Answer 26

quite late in foetal development - they take 20 seeks to develop
- they occur from 9-20 weeks of gestation

Question 27

what happens if microvilli don’t develop

Answer 27

• you can get malabsorption
• diarrhoea
• become anaemic

Question 28

describe how intestinal elongation happens

Answer 28

• it is rapid in utero

- continues more slowly through puberty

Question 29

when do microvillous enzymes begin to appear

Answer 29

• they begin to appear at 8 weeks

Question 30

when does lactase peaks for delivery

Answer 30

• peaks at time of delivery at 40 weeks

Question 31

when does IgA arise

Answer 31

arises around the time of delivery

Question 32

when is motility and feeding develop in pregnancy

Answer 32

• Sucking and swallowing present early
  (amniotic fluid)
• but unable to swallow and breathe before 32-34 weeks of gestation

Question 33

when does chewing occur

Answer 33

Teeth appear at 6 months of age

Ability to coordinate mouth and tongue in swallowing

At same age, narrow time window to establish otherwise a problem with lumpy foods

Question 34

why is cows milk bad for a baby

Answer 34

• it is high in protein
• it is high in sodium
• it is high in calcium
• it is high in phosphate

Question 35

what does infant formula try to do

Answer 35

• it trys to match mature human breast milk

Question 36

describe breast milk versus cows milk

Answer 36

Lower protein
- Whey > Casein – more easily digested

Lower minerals eg Na – lower solute load

Essential fatty acids – better absorbed

Lipase - digestion

Anti-infective -

Vits A/C/D greater

Lower calcium and phosphorus (high phosphorus in CM leads to hypocalcemic tetany)

Question 37

how many bottles of milk does a baby have a day at the age of (months)

• Newborn
• 2
• 3
• 5
• 7
• 8
• 9

Answer 37

• 6-8
• 5-6
• 5
• 4
• 3
• 3
• 2-3

Question 38

when can you stop using infant formula if you are not breast feeding

Answer 38

12 months

Question 39

from what age should weaning commence

Answer 39

6 months

Question 40

what foods should be introduces at 6 months

Answer 40

• Foods known to be potentially allergenic can be introduced*
• Eggs – egg yolk first, then egg white
• Gluten-containing foods – flour, bread, pasta and wheat-based cereals