L5 Anatomy Development Flashcards
Septum transversum
Unsplit part of intraembryonic mesoderm which lies cranial to the pericardial cavity
is the cavity with in the embryo which developed by dividing the lateral plate mesoderm of the embryo
Intraembryonic coelom
lateral plate mesoderm of the embryo divides into
Somatopleuric mesoderm
Splanchnopleuric mesoderm
After head fold formation where is the location of the septum transversum?
Caudal to the pericardial cavity and ventral to the foregut
The pleural cavity, pericardial cavity and peritoneal cavities are the body cavities which are continuous with each other at one time of development, and develop into individual body cavities when?
With the development of the diaphragm
Shape of Intraembryonic coelom
Horseshoe shaped
What is the intraembryonic coelom divided into?
Pericardial coelom in the midline
Peritoneal coelom & pericardioperitoneal canals on either side.
Pericardial coelom
Pericardium
Peritoneal coelom
Peritoneum
Pericardio-peritoneal Canals
R & L pleural cavities
Where will the pleuroperitoneal membranes develop from?
The walls of the pericardioperitoneal canals
Development of diaphragm:
What will the pleuroperitoneal membranes do once they develop from the walls of the pericardioperitoneal canal?
Close the communication between the pericardioperitoneal canal and the peritoneal cavity
Foregut
Esophagus
suspended from dorsal body wall by its mesentery, which will also contributes for development of the diaphragm
Foregut/esophagus
closure of pericardioperitoneal canal by pleuro-peritoneal membrane
Development of the diaphragm
Development of the diaphragm
closure of pericardioperitoneal canal by pleuro-peritoneal membrane
Two structures that contribute in the development of the diaphragm:
- Septum transversum (Unsplit part of intraembryonic mesoderm)
- Dorsal mesentery of esophagus
Is the phrenic nerve a somite?
Yes
Where does the Peripheral part of the diaphragm develop from?
Body wall
Where does the Central Tendon of the diaphragm develop from?
Septum transversum
Exam q: Where does the posterolateral part of the diaphragm develop from?
Pleuroperitoneal Membrane
Where does the Crura of the Diapgragm develop from?
Dorsal Mesentery of Esophagus
Innervation Of The Diaphragm
Musculature (Motor) - Phrenic Nerve (C3,4,5)
Sensory- Centarl tendon and Major part of the Muscular part by Phrenic nerve
Peripheral part- Intercostal nerves
What develops with the development of pleuro-peritoneal membrane?
pericardio-peritoneal canal develops into pleural cavity. Developing lung grows into pleural cavity.
Posterolateral defect of The Diaphragm
- Due to failure of development of Pleuroperitoneal membrane
- Congenital Diaphragmatic hernia
- Pulmonary Hypoplasia
- Life threatening breathing difficulties
- One or both sides
Eventration of The Diaphragm
eventration = herniation
Abdominal contents pushed through THIN posterolateral part of the diaphragm -which is developed from pleuroperitoneal membrane- (colon pushed into thoracic region)
What is the laryngotracheal groove?
A small median groove that develops in the floor of the developing pharynx
Exam q: Epithelial proliferation of Laryngotracheal groove give rise to
epithelium and glands of larynx, trachea, bronchi, and pulmonary epithelium
Where does the larynx develop?
Larynx develops around the laryngotracheal groove.
Lining Epithelium of the larynx
develops from endoderm of cranial end of laryngotracheal diverticulum
Cartilage of larynx
4th and 6th arch (From Neural crest cells)
Development of epiglottis
3rd and 4th arch
Caudal part of Hypobranchial eminence
Laryngeal Muscles- develop from
4th and 6th arch
Nerve supply-Laryngeal branches of VAGUS nerve)
Laryngeal atresia
Congenital high air way obstruction syndrome
Development of Trachea
Trachea develops from the lagyngotracheal groove as respiratory diverticulum, which soon divides into left and right lung buds.
Epithelium and Glands of trachea
Endodermal lining of larygotracheal tube
Cartilage, Connective tissue, Muscles
Splanchnic mesesoderm
Tracheal Stenosis and Atresia
Narrowing of trachea
Tracheal Diverticulum
Out growth from trachea
“Pouch growth”
Development of Bronchi and Lungs
Lung tissue develops from proliferation of the cells of lung buds at end of developing respiratory diverticulum.
Epithelium and Glands of lungs
Endodermal lining of lung buds
Cartilage, Connective tissue, Muscles of lungs
Splanchnic mesoderm
Agenesis of lungs
Non development of lungs
Lung Hypolasia
Reduced development of lungs
Accessory lung
Due to additional branching from respiratory divierticulum
Lobe of Azygos vein
Due to growth of lung tissue medial to azygos vein
Congenital Lung Cyst
Closed sacs, due to separation of alveolar sac etc.
Respiratory distress syndrome
Surfactant defeciency
What are the 4 Lung developmental Periods?
- Pseudoglandular Period (5 – 17weeks)
- Canalicular Period (16- 25 weeks)
- Terminal sac Period (24 weeks – birth)
- Alveolar Period (Late fetal Period to child hood)
1.Pseudoglandular Period (5 – 17weeks)
- Lung resembles exocrine gland
- Major elements are formed
- Alveoli are not formed (Fetus born during this period fails to survive)
2.Canalicular Period (16- 25 weeks)
- Lumen of bronchi and terminal bronchiole increases
- Becomes highly vascular
- Alveolar ducts are formed
- Terminal sac Period (24 weeks – birth)
- Terminal sacs are formed
- Capillaries bulge into alveoli
- Intimate contact between epithelial and endothelial cells established
- Type I (lining) and Type II (surfactant secretion) alveolar cells are formed
- Alveolar Period (Late fetal Period to child hood)
- Formation of alveoli
- Exponential increase in surface of air blood barrier
- 50 million alveoli in full-term, 300 million by eighth year.
Floor of the Pharynx
4th Week
Tracheoesophageal Fistula
Communication between trachea and esophagus
Laryngotracheoesophageal cleft
Communication between larynx and trachea with osesophagus.
Air goes to the stomach and food goes to the lung leading to infection.
Intradabdominal P increases during birth.
Lower respiratory tract
Larynx and below (larynx, trachea, primary bronchi and lungs)
Lung tissue develops from
proliferation of the cells of lung buds at end of developing respiratory diverticulum.
respiratory diverticulum divides into
left and right lung buds
