Difference between revisions of "Respiratory System Development"

From Embryology
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File:Gray0974.jpg|secondary lobule from the human lung
 
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File:Historic-lungs.jpg|heart and lungs
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File:Gray0968.jpg|transverse section of the thorax showing the middle and posterior mediastinum
 
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Revision as of 07:50, 4 August 2010

Introduction

Respiratory system overview (stage 13)

The respiratory system does not carry out its physiological function (of gas exchange) until after birth. The respiratory tract, diaphragm and lungs do form early in embryonic development. The respiratory tract is divided anatomically into 2 main parts: 1. upper respiratory tract, consisting of the nose, nasal cavity and the pharynx; 2. lower respiratory tract consisting of the larynx, trachea, bronchi and the lungs.

In the head/neck region, the pharynx forms a major arched cavity within the phrayngeal arches. The lungs go through 4 distinct histological phases of development and in late fetal development respiratory motions and amniotic fliud are thought to have a role in lung maturation.

Development of this system is not completed until the last weeks of Fetal development, just before birth. Therefore premature babies have difficulties associated with insufficient surfactant (end month 6 alveolar cells type 2 appear and begin to secrete surfactant).

--Mark Hill 09:25, 14 April 2010 (EST) Page Template only - content from original UNSW Embryology site currently being edited and updated.

Respiratory Links: respiratory | Science Lecture | Lecture Movie | Med Lecture | Stage 13 | Stage 22 | upper respiratory tract | diaphragm | Histology | Postnatal | respiratory abnormalities | Respiratory Quiz | Respiratory terms | Category:Respiratory
Historic Embryology  
1902 The Nasal Cavities and Olfactory Structures | 1906 Lung | 1912 Upper Respiratory Tract | 1912 Respiratory | 1913 Prenatal and Neonatal Lung | 1914 Phrenic Nerve | 1918 Respiratory images | 1921 Respiratory | 1922 Chick Pulmonary Vessels | 1934 Right Fetal Lung | 1936 Early Human Lung | 1937 Terminal Air Passages | 1938 Human Histology

| original page

System Links: Introduction | Cardiovascular | Coelomic Cavity | Endocrine | Gastrointestinal Tract | Genital | Head | Immune | Integumentary | Musculoskeletal | Neural | Neural Crest | Placenta | Renal | Respiratory | Sensory | Birth

Some Recent Findings

Clinical

  • Lung Function and Respiratory Symptoms at 11 Years in Extremely Preterm Children[1] "Following extremely preterm birth, impaired lung function and increased respiratory morbidity persist into middle childhood, especially those with bronchopulmonary dysplasia (BPD). Many of these children may not be receiving appropriate treatment."
  • Pediatric lung transplantation.[2] "Lung transplantation is an accepted therapy for selected pediatric patients with severe end-stage vascular or parenchymal lung disease. Collaboration between the patients' primary care physicians, the lung transplant team, patients, and patients' families is essential. The challenges of this treatment include the limited availability of suitable donor organs, the toxicity of immunosuppressive medications needed to prevent rejection, the prevention and treatment of obliterative bronchiolitis, and maximizing growth, development, and quality of life of the recipients. This article describes the current status of pediatric lung transplantation, indications for listing, evaluation of recipient and donor, updates on the operative procedure,graft dysfunction, and the risk factors, outcomes, and future directions."

Textbooks

  • Human Embryology Larson Chapter 9 p229-260
  • The Developing Human: Clinically Oriented Embryology (6th ed.) Moore and Persaud Chapter 12 p271-302
  • Before We Are Born (5th ed.) Moore and Persaud Chapter 13 p255-287
  • Essentials of Human Embryology Larson Chapter 9 p123-146
  • Human Embryology Fitzgerald and Fitzgerald Chapter 19,20 p119-123
  • Anatomy of the Human Body 1918 Henry Gray 1. The Respiratory Apparatus

Objectives

  • Describe the development of the respiratory system from the endodermal and mesodermal components.
  • Describe the main steps in the development of the lungs.
  • Describe the development of the diaphragm and thoracic cavities.
  • List the respiratory changes before and after birth.
  • Describe the developmental aberrations responsible for the following malformations: tracheo - oesophageal fistula (T.O.F); oesphageal atresia; diaphragmatic hernia; lobar emphysema.

Computer Activities

Development Overview

Lung alveoli development cartoon.jpg

Week 4 - laryngotracheal groove forms on floor foregut.

Week 5 - left and right lung buds push into the pericardioperitoneal canals (primordia of pleural cavity)

Week 6 - descent of heart and lungs into thorax. Pleuroperitoneal foramen closes.

Week 7 - enlargement of liver stops descent of heart and lungs.

Month 3-6 - lungs appear glandular, end month 6 alveolar cells type 2 appear and begin to secrete surfactant.

Month 7 - respiratory bronchioles proliferate and end in alveolar ducts and sacs.

Lung Development Stages

  • week 4 - 5 embryonic
  • week 5 - 17 pseudoglandular
  • week 16 - 25 canalicular
  • week 24 - 40 terminal sac
  • late fetal - 8 years alveolar

References

  1. <pubmed>20378729</pubmed>
  2. <pubmed>20371042</pubmed>


Reviews

Articles

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  • Respiratory System Development - All (30795) Review (3706) Free Full Text (7943)
  • Respiratory Development - All (28939) Review (5876) Free Full Text (7203)

Search Pubmed: Respiratory System Development | Respiratory Development

Additional Images

Upper respiratory tract

Lower respiratory tract

Diaphragm

Terms

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

Cite this page: Hill, M.A. (2020, April 8) Embryology Respiratory System Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Respiratory_System_Development

What Links Here?
© Dr Mark Hill 2020, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G