Hy Embryology 11 Part 2

Front 1

What are the components of the upper respiratory system?

Back 1

-Nose
-Nasopharynx
-Oropharynx

Front 2

What are the components of the lower respiratory tract?

Back 2

-Larynx
-Trachea
-Bronchi
-Lungs

Front 3

What is the first sign of development of the lower respiratory system?

Back 3

The formation of the respiratory diverticulum in the ventral wall of the primitive foregut during week 4

Front 4

When does the respiratory diverticulum form?

Back 4

Week 4

Front 5

Describe the development of the lower respiratory system

Back 5

1. The first sign of development if the formation of the respiratory diverticulum in the ventral wall of hte primitive foregut
2. The distal end of the respiratory diverticulum enlarges to form the lung bud
3. The lung bud divides into two bronchial buds that branch into the main (primary), lobar (secondary), segmental (tertiary), and subsegmental bronchi
4. The respiratory diverticulum initially is in open communication with the foregut, but eventually they become separated by indentations of mesoderm - the tracheoesophageal folds. Whtn the tracheoesophageal folds fuse in the midline to form the tracheoesophageal septum, the foregut is divided into the trachea ventrally and esophagus dorsally

Front 6

Describe the development of the distal end of the respiratory diverticulum

Back 6

The distal end of the respiratory diverticulum enlarges to form the lung bud

Front 7

Describe the development of the lung bud

Back 7

1. The distal end of the respiratory diverticulum enlarges to form the lung bud

2. The lung bud divides into two bronchial buds that branch into the main (primary), lobar (secondary), segmental (tertiary), and subesegmental bronchi

Front 8

What separates the respiratory diverticulum from the foregut?

Back 8

The development of the tracheoesophageal folds

Front 9

Describe the tracheoesophageal folds

Back 9

They fuse in the midline to form the tracheoesophageal septum, the foregut is divided into the trachea ventrally and the esophagus dorsally

Front 10

Descrion the formation of the trachea

Back 10

The foregut is divided into the trachea ventrally and the esophagus dorsally by the tracheoesophageal folds, which fuse to form the tracheoesophageal septum

Front 11

Describe tracheoesophageal fistulas

Back 11

A tracheoesophageal fistula is an abnormal communication between the trachea and esophagus that results from improper division of foregut by the tracheoesophageal septum.

Front 12

What are tracheoesophageal fistulas associated with?

Back 12

It is generally associated with esophageal atresia and polyhydraminios

Front 13

Describe the clinical features of tracheoesophageal fistulas

Back 13

1. Excessive accumulation of saliva or mucus in the nose and mouth

2. Episodes of gagging and cyanosis after swallowing milk

3. Abdominal distension after frying

4. Reflux of gastric contents into lungs, causing pneumonitis

Front 14

What are the diagnostic features of tracheoesophageal fistulas?

Back 14

1. Inability to pass a catheter into the stomach

2. Radiographs demonstrating air in the infant's stomach

Front 15

What is the most common type of tracheoesophageal fistulas?

Back 15

Tracheoesophageal fistula at the distal 1/3 end of the trachea

Front 16

Describe the stages of development of the bronchi

Back 16

1. The lung bud divides into two bronchial buds

2. In week 5 of development, bronchial buds enlarge to form main (primary) bronchii

3. The main bronchi further subdivide into lobar (secondary) bronchi (three on the right side and two of the left side, corresponding to the lobes of the adult)

4. The lobar bronchi further subdivide into segmental (tertiary) bronchi (10 on the right side and 9 in the left side), which further subdivide into subsegmental bronchi

5. The segmental bronchi are the primordia of the bronchopulmonary segments, which are morphologically and functionally separate respiratory units of the lung

Front 17

When do the bronchial buds enlarge to form main (primary) bronchi?

Back 17

Week 5

Front 18

What occurs in lung develop in week 5?

Back 18

The bronchial buds enlarge to form main (primary) bronchi

Front 19

How many lobar bronchi are there?

Back 19

3 on the right

2 on the left

Front 20

How many segmental bronchi are there?

Back 20

10 on the right side

9 on the left side

Front 21

What are bronchopulmonary segments?

Back 21

1. Morphologically and functionally separate respiratory units of the lung

2. These are segments of lung tissue supplied by a segmental (tertiary) bronchus.

3. Surgeons can resect diseased lung tissue along bronchopulmonary segmental rather than remove the entire lobe

Front 22

Describe congenital lobar emphysemia

Back 22

1. Characterized by progressive overdistention of one of the upper lobes or the right middle lobe with air

2. There is no destruction of the alveolar walls

3. Many cases involve collapsed bronchi due to failure of bronchial due to failure of bronchial cartilage formation

4. Air can be inspired through collapsed bronchi but cannot be expired

5. During the first few days of life, fluid may be trapped in the involved lobe, producing an opaque, enlarged hemithorax. Later the fluid is resorbed and the classic radiological appearance of an emphysematous lobe with generalized radiolucency (hyperlucent) is apparent.

Front 23

Describe the consequences of congenital lobar emphysema on the first few days of life

Back 23

1. During the first few days of life, fluid may be trapped in the involved lobe, producing an opaque, enlarged hemothorax

3. Later, the fluid is resorbed and the classic radiological appearance of an emphysematous lobe with generalized radiolucency (hyperlucent) is apparent

Front 24

Describe respiration of congenital lobar emphysema

Back 24

In this situation, air can be inspired through collapsed bronchi but cannot be expired

Front 25

Describe congenital bronchogenic cysts

Back 25

1. Congenital bronchogenic cysts represent an abnormality in bronchial branching and may be found within the mediastinum (most commonly) or intrapulmonary

2. Intrapulmonary cysts are round, solitary, sharply marginated, and fluid filled and do not initially communicate with the traceobronchial tree

3. Because intrapulmonary bronchogenic cysts contain fluid, they appear as water-density masses on chest radiographs

4. These cysts may become air filled as a result of infection or instrumentation

Front 26

Describe the intrapulmonary cysts in congenital bronchogenic cysts

Back 26

Round, solitary, sharply marginated, and fluid filled and do not initially communicate with the tracheobronchial tree