Transcript Digestive System Alimentary Canal develops from endoderm and splanchnic mesoderm

Digestive System
Alimentary Canal develops from endoderm and splanchnic mesoderm
Formation of the human digestive system, depicted at about (A) 16 days, (B) 18 days, (C) 22 days, and (D) 28 days.
15.24 Formation of the human digestive system (Part 1)
15.24 Formation of the human digestive system (Part 2)
Epi Ecto invaginates to meet endo
to form Stomodeum &
Proctodeum
A septum separates the cloaca into
anus (dorsal) and urogenital
(ventral
Branchial Apparatus: the pharynx forms cavity within arches.
Arch (mesoderm), Groove (epi ecto), Pouch (endo)
15.25 Formation of glandular primordia from the pharyngeal pouches (Part 1)
Branchial Apparatus
The fate of the pharyngeal pouches: 1st forms the external auditory passages
Arch (mesoderm), Groove (epi ecto), Pouch (endo)
15.24 Formation of the human digestive system (Part 3)
Digestive System
Alimentary Canal develops from endoderm and splanchnic mesoderm
four layers of the digestive tract the mucosa (1),
the submucosa (2),
the muscularis (3),
the serosa (4).
)
Peritoneum visceral vs parietal
Mesentery
Alimentary Canal and Association Organs
Differentiation of associated organs at the level of the forming stomach occurs both dorsally (spleen) and
ventrally (liver).
15.26 Regional specification of the gut endoderm and splanchnic mesoderm through reciprocal
interactions (Part 1)
15.27 Pancreatic development in humans (Part 1)
15.30 Partitioning of the foregut into the esophagus and respiratory diverticulum during the third
and fourth weeks of human gestation
15.31 Ability of presumptive lung epithelium to differentiate with respect to the source of the
inducing mesenchyme
respiratory tract and aveolar epithelium are endoderm in origin
with mesoderm contributing surrounding tissue
respiratory system not gas exchange source until after birth
late in fetal development ventilation with amniotic fluid role in lung maturation.
Fetal Respiratory Distress Syndrome - insufficient
surfactant (end month alveolar cells secrete surfactant).
15.32 The immune system relays a signal from the embryonic lung