Development of the GI function and nutritional needs in early life Flashcards
what is the blood supply of the
- foregut
- midgut
- handout
Foregut – supplied by the celiac artery
Midgut the superior mesenteric artery
Hindgut – interior mesenteric artery
what are some foregut developmental abnormalities
- oesophageal atresia
- tracheo-oesophageal fistulae
- congenital hiatus hernia
- pyloric stenosis
- duodenal atreasia
what is oesophageal atresia
- this is when there is a blockage in the oesophagus, this means that they will have difficulty swallowing
how does oesophagus and respiratory tract form
the oesophagus and the respiratory tract start of combined and then they split of into a septum into two different tubes
what can develop if the trachea does not separate from the oesophagus
- 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
why do babies get reflux
- can have reflux due to being overfeed
- mothers can over feed the baby because it cry so they get too much milk
what causes GORD
- lower oesophageal sphincter is relaxed and it hasn’t tightened yet
how does GORD increase or decrease through the infants life
- 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
what is duodenal atresia
- 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
what is a diaphragmatic hernia
- 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
describer how the midgut grows
- 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
when is the position of the abdominal organs completed
- it is completed as the ascending colon attaches to the posterior abdominal wall
what are some midgut developmental abnormaities
- 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
what happens in midgut volvulus with ischemai
- 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
what is the duodenum-jejunum junction anchored by
- it is anchored by the ligament of tretiz
when does intestinal malrotation occur
- it occurs when there is failure of the normal rotation and fixation
how do you treat ompehalcel or gastroshesis
- 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
what does persistence of the vitelline duct give rise to
Meckels diverticulum
what happens in meckels diverticulum
- 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
how do you identify ectopic gastric mucosa in meckel’s diverticulum
- uses nuclear medicine scan
- shows a spot where there should not be a spot
what are some handgun abnormalities
anorectal abnormalities
what is a imperforate anus
- Low imperforate anus
- high imperforate anus
- Not have a hole in the anus
Picked up at birth
what do neural crest cells give rise to
enteric ganglia
describe how neurocrest cells develop
- 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
what is hirschprungs disease
- 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
when do vili develop
quite late in foetal development - they take 20 seeks to develop
- they occur from 9-20 weeks of gestation
what happens if microvilli don’t develop
- you can get malabsorption
- diarrhoea
- become anaemic
describe how intestinal elongation happens
- it is rapid in utero
- continues more slowly through puberty
when do microvillous enzymes begin to appear
- they begin to appear at 8 weeks
when does lactase peaks for delivery
- peaks at time of delivery at 40 weeks
when does IgA arise
arises around the time of delivery
when is motility and feeding develop in pregnancy
- Sucking and swallowing present early
(amniotic fluid) - but unable to swallow and breathe before 32-34 weeks of gestation
when does chewing occur
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
why is cows milk bad for a baby
- it is high in protein
- it is high in sodium
- it is high in calcium
- it is high in phosphate
what does infant formula try to do
- it trys to match mature human breast milk
describe breast milk versus cows milk
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)
how many bottles of milk does a baby have a day at the age of (months)
- Newborn
- 2
- 3
- 5
- 7
- 8
- 9
- 6-8
- 5-6
- 5
- 4
- 3
- 3
- 2-3
when can you stop using infant formula if you are not breast feeding
12 months
from what age should weaning commence
6 months
what foods should be introduces at 6 months
- 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
