2010 Lecture 9

From Embryology
Lecture Notice - Mark Hill
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Endoderm Development

Introduction

The early developing gastrointestinal tract

This lecture will cover the early development of the endoderm layer of the trilaminar embryo as it contributes to the lining, glands and organs of the gastrointestinal tract (GIT). Note that we will be returning in the laboratory and later to discuss the gastrointestinal tract, associated organs and physical growth changes.

Gastrulation, or gut formation, was historically the easiest observable feature of frog development. In human development, during the 4th week the 3 distinct portions (fore-, mid- and hind-gut) extend the length of the embryo and will contribute different components of the GIT. The large mid-gut is generated by lateral embryonic folding which "pinches off" a pocket of the yolk sac, the 2 compartments continue to communicate through the vitelline duct.

On this current page there is a brief developmental overview and stage 13/14 embryo overview. The oral cavity (mouth) is formed following breakdown of the buccopharyngeal membrane (=oropharyngeal or oral) and contributed to mainly by the pharynx lying within the pharyngeal arches. The opening of the GIT means that it contains amniotic fluid, which is also swallowed later in development. From the oral cavity the next portion of the foregut is initially a single gastrointestinal (oesophagus) and respiratory (trachea) common tube, the pharynx which lies behind the heart. Note that the respiratory tract will also form from a ventral bud arising at this level.

Lecture Objectives

  • Understanding of germ layer contributions to the early gastrointestinal tract (GIT)
  • Understanding of the folding of the GIT
  • Understanding of three main GIT embryonic divisions
  • Understanding of associated organ development (liver, pancreas, spleen)
  • Brief understanding of mechanical changes (rotations) during GIT development
  • Brief understanding of gastrointestinal abnormalities

Gastrointestinal Tract Movies

Endoderm 002 icon.jpg Gastrointestinal tract growth 01 icon.jpg Lesser sac 01 icon.jpg Greater omentum 001 icon.jpg
Endoderm Tract Growth Lesser Sac Greater Omentum
Quicktime version Quicktime version Quicktime version Quicktime version


Glossary Links

Glossary: A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Symbols | Term Link

Course Content 2010

Embryology Introduction | Cell Division/Fertilization | Lab 1 | Week 1&2 Development | Week 3 Development | Lab 2 | Mesoderm Development | Ectoderm, Early Neural, Neural Crest | Lab 3 | Early Vascular Development | Placenta | Lab 4 | Endoderm, Early Gastrointestinal | Respiratory Development | Lab 5 | Head Development | Neural Crest Development | Lab 6 | Musculoskeletal Development | Limb Development | Lab 7 | Kidney | Genital | Lab 8 | Sensory | Stem Cells | Stem Cells | Endocrine | Lab 10 | Late Vascular Development | Integumentary | Lab 11 | Birth, Postnatal | Revision | Lab 12 | Lecture Audio | Course Timetable


Cite this page: Hill, M.A. (2024, March 29) Embryology 2010 Lecture 9. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/2010_Lecture_9

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© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G