GI Flashcards by Gina Fong

When is lactase at adult levels?

36 weeks

How well did you know this?

Not at all

Perfectly

When is hcl detected in stomach

32 weeks

How well did you know this?

Not at all

Perfectly

When do intestinal disaccharidases reach adult levels?

Lactase 36 weeks

All others 28 weeks

How well did you know this?

Not at all

Perfectly

What is the colonic salvage pathway?

Colonic bacteria ferment malabsorbed carbohydrate to acids which are absorbed in colon

How well did you know this?

Not at all

Perfectly

How developed are dipeptidase and amino acid transport capacity in neonates? How about chymotrypsin and trypsin?

These are components of protein digestion.
Well developed in early life: dipeptidase and amino acid transport capacity
Decreased in preterm and term: chymotrypsin and trypsin

How well did you know this?

Not at all

Perfectly

What are steps to fat digestion?

Bile acid emulsification of fat globules
Triglyceride hydrolysis by lipase
Solubilization of lipolytic products
Fatty acid transfer across intestinal mucosa
TG resynthesis from fatty acids in enterocytes
Chylomicron formation in enterocytes
Secretion of chylomicrons into portal blood or lymphatics

How well did you know this?

Not at all

Perfectly

When does GI tract start forming?

5th week of gestation

*but at 3.5 weeks there is a liver bud w foregut and hindgut present

How well did you know this?

Not at all

Perfectly

What is length of GI tract at birth?

275-300cm (200cm is small intestine)

How well did you know this?

Not at all

Perfectly

What impact do enteral feeds have on GI hormones?

Increase plasma concentration of GI hormones (GIP, Gastrin, Motilin, GLP-2)

How well did you know this?

Not at all

Perfectly

What proportion of the immune system is the gut?

70%

How well did you know this?

Not at all

Perfectly

What type of fatty acids need bile acids?

Long chain fatty acids (short and medium chain do not need)

How well did you know this?

Not at all

Perfectly

What is level of amylase in newborns?

Decreased in preterm and term.
Reaches adult levels ~6 months
Both salivary and pancreatic amylase decreased

How well did you know this?

Not at all

Perfectly

How are glucose and galactose transported in intestine? Which transporter?

Active transport (across apical side of enterocyte)
Transporter: SGLT1 (apical), then GLUT2 (basal)

How well did you know this?

Not at all

Perfectly

How is fructose transported in the intestine? What transporter?

Facilitated/passive transport

Transporter: GLUT5 (apical), GLUT2 (basal)

How well did you know this?

Not at all

Perfectly

What proportion of lactose reaches colon? Impact?

20%

Lowers stool pH
Promotoes growth of Lactobacillus and Bifidobacteria

How well did you know this?

Not at all

Perfectly

Where are lipids absorbed? Vitamin B12? Sodium/Cl/K? Short chain fatty acids?

Lipids: jejunum
Vitamin B12: ileum
Na/Cl/K: colon
Short chain fatty acids: colon

How well did you know this?

Not at all

Perfectly

What proportion of TEF have other anomalies?

30-40%
*associated with VACTERL
Problem at 4th week gestation

How well did you know this?

Not at all

Perfectly

What type of TEF most common? Second most common?

Upper pouch w distal TEF just above carina (85%)

2. Isolated EA, no tracheal communication (8%)

How well did you know this?

Not at all

Perfectly

What are risks for spontaneous gastric perforation?

Perinatal stress, postnatal steroids. 20% with no known risk

2-7 days of life

How well did you know this?

Not at all

Perfectly

What is incidence of SIP in VLBWs? ELBWs?

VLBW: 2-3%
ELBW: 5%

What are risk factors for SIP?

PDA treated with indocin

Vasopressor support

What is most common site for SIP?

Terminal ileum

What is apple core a sign of on ultrasound?

Pyloric stenosis (also referred to as “string sign”)

What is risk for sibling if a child has pyloric stenosis? What if parent had it?

Sibling: 3% risk to next child
Parent: Mom - 19% son, 7% daugther
Dad - 5.5% son, 2.4% daughter

What is the electrolyte disturbance in pyloric stenosis?

Hypochloremic, hypokalemic metabolic alkalosis

What is double bubble? Triple bubble?

Double = duodental atresia (T21 31%), 20% with malrotation; associated with disorders Triple: jejunal/ileal atresia “apple peel deformity”; usually single atresia. Most common is distal ileum

What is a corkscrew sign on upper GI?

Malrotation (2/3 of pts present in first month) Presence of ladds bands Associated disorders: CDH, abd wall defects, Beckwith Wiedemann syndrome, intestinal atresias

Where does meconium ileus occur?

Terminal ileum, 90% have CF (but only 10-15% of CF have mec ileus)

When does meconium ascites occur?

Type of meconium peritonitis, occurs within days of birth. NO calcifications (too early to form)

What is treatment for majority of pts with mec peritonitis?

Surgery (some will be ok but most need surgery)

What causes microcolon? Association?

Functional immaturity of ganglion cells Assoc w maternal diabetes Rectum is NORMAL (differentiates from Hirschsprungs)

What is risk of Hirschsprung if sibling with disease? Associated syndromes?

3-5%; 80% of Hirschsprung pts are male 1/3 have a relative with Hirschsprung Associated: T21, heterochromia, Waardenburg, congenital deafness, 13q deletion, pheochromocytoma, NF, neuroblastoma

What is the pathophysiology of Hirschsprungs disease?

Failure of NCC migration at 8-10 weeks GA 75-80% only involve rectosigmoid 5-10% complete colon

What are possible etiologies of gastroschisis?

1. Involution of right umbilical vein 2. Teratogenic exposures (aspirin, ibuprofen, cocaine) 3. Genetic (though not known)

What proportion of gastroschisis have other anomalies?

100% have malrotation 16% have other GI anomalies (volvulus, atresias) No inc risk of chromosomal anomalies

What syndromes are associated with omphalocele?

Trisomy 13, 18, 21 Pentalogy of Cantrell (omphalocele, CDH, VSD or diverticulum of LV, sternal cleft, ectopia cordis - heart outside body) Beckwith Wiedenann OEIS complex (omphalocele, exstrophy of bladder, imperforate anus, spinal deformity)

What is pathophysiology of omphalocele?

Intestinal loops fail to return to body at 11 weeks GA or somatic folds fail by 18 wks GA

How many with omphalocele have associated defects? What is survival?

80%, also 3:1 male: female | Survival 30-40% (90% if isolated)

What are intrahepatic causes of cholestasis?

``` Neonatal idopathic hepatitis (most common) Alagille syndrome (paucity of intrahepatic bile ducts) Non syndromic paucity of bile ducts ```

What are extrahepatic causes of cholestasis?

``` Biliary atresia (most common) Sclerosing cholangitis Bile duct stenosis Choledochal cyst Bile plug syndrome ```

What is cause of bilisry atresia? What is seen on histology?

Progressive sclerosis of extrahepatic bile ducts | Histology: bile duct proliferation

What is histology of idiopathic neonatal hepatitis?

Multinucleated giant cells

What is composition of Intralipid? SMOF? Omegaven?

IL: soybean, egg phospholipids, glycerin SMOF: soybean, MCT, olive, fish Omegaven: fish oil triglycerides

What is the mutation in Alagille syndrome?

JAG1

What are the criteria for bells staging in NEC? I, IIA, IIB, IIIA, IIIB?

I - suspected, normal xray or just dilation, scant blood IIA - mild, focal pneumatosis, bloody stools IIB - diffuse pneumatosis, portal venous gas IIIA - diffuse pneumatosis with resp failure and met acidosis, DIC, oliguria IIIB - shock, free air

What is esophageal sphrincter tone in term infant? Preterm?

Term - 18 mmHg | Preterm - 4 mmHg

Why does ranitidine cause bradycardia?

Ranitidine blocks histamine, there are histamine receptors on heart -> bradycardia

When does pancreatic lipase reach adult levels? What helps before then?

4-5 months | Prior to that, rely on lingual and gastric lipase

What is Pentalogy of Cantrell?

Abnormal fusion of abdominal folds (lateral and cephalic) 1. Cleft sternum 2. Anterior midline diaphragm abnl 3. Pericardial defect 4. Ectopic cordis (heart outside) 5. Upper abd omphalocele