GI: Embryology Flashcards
1
Q
Gut Tube
A
- 3 regions
- Foregut
- from head fold
- Midgut
- mostly from lateral folds
- Hindgut
- from tail fold
- Foregut
- Endoderm
- forms most epithelium and glands
- Ectoderm
- forms epithelial at cranial and caudal ends
- Splanchic Mesoderm
- forms muscles and connectives tissues
2
Q
Derivatives of foregut
A
- Pharynx & pouch derivatives
- Thyroid
- Lower respiratory system
- trachea
- bronchi
- lungs
- Esophagus
- stomach
- duodenum (proximal to bile duct)
- liver
- gall bladder
- biliary apparatus (hepatic duct and bile duct)
- pancreas
- Digestive organs supplied by celiac trunk
- except for most of esophagus
3
Q
Esophagus
A
- Develops caudal to pharynx
- 7th week=final week
- Pharyngeal arch mesoderm
- forms superior esophagus
- striated muscle
- Splanchic Mesoderm
- inferior esophagus
- smooth muscle
4
Q
Stomach
A
- Appears 4th week as spindle shaped dilation
- Dorsal border (Abdominal wall) grows faster than ventral
- forms greater and lesser curvature
- Rotates 90 degress clockwise around carniocaudal axis
5
Q
Hypertrophic Pyloric Stenosis
A
- Marked thickening of circular pyloric muscles
- affects 1:150 males, 1:750 Females
- projectile vomiting
6
Q
Duodenum
A
- Develops from:
- distal foregut
- proximal midgut
- Supplied by celiac and Superior Mesentary artery
7
Q
Umbilical Hernia
A
- imperfect closed umbilicus after intestines return to abdominal cavity
- range:; 1-5 cm diameter
- Affects 15-23% newborn in US
8
Q
Ileal Diverticulum
A
- aka Meckel Diverticulum
- Remnant of proximal omphaloenteric duct
- becomes inflamed
- mimics symptoms of appendicitis
- 2-4% people
9
Q
Anal Canal
A
- Cloaca becomes:
- rectum
- superior 2/3 anal canal
- Proctodeum–>inferior 1/3 anal canal
- Pectinate Line
- ectoderm-endoderm junction
- site of seperation for vascular and neural supplly of anal canal
10
Q
Clinical: Anal Canal
A
- Superior anal canal
- endodermal hindgut
- autonomic nerves
- Hemorrhoids-internal
- venous drainage–>hepatic portal system
- Painless
- Tumors:
- inferior mesenteric nodes in abdominopevlic cavity
- Painless
- Inferior anal canal
- ectodermal proctodeum
- somatic nerves
- Hemorrhoids-external
- venous drainage–>vena cava
- painful
- Tumors:
- Superficial inguinal nodes in groin
- painful