Pul 1 - Anatomy and Physiology

Question 1

What do we see on x-ray in an esophageal atresia?

Answer 1

Gastric bubbles because the lower part of the esophagus is directly connected to the trachea itself, causing air in the stomach.

Question 2

What is an H type tracheoesophageal atresia?

Answer 2

It is when a fistula, but no atresia occurs, between the trachea and esophagus, causing an H looking presentation when viewed from the side.

Question 3

Which type of epithelium lines the esophagus? And what happens to it on smokers?

Answer 3

Lined with ciliated columnar epithelium. On smokers, there is metaplasia of to squamous cell type (the other way around in Barret esophagus).

Question 4

What is another name for Kartagener syndrome and what is it?

Answer 4

Primary ciliary dyskinesia, it causes non-functional cilia in respiratory tract, sinuses, eustachian tubes, fallopian tubes, flagella of sperm.

Question 5

What is pathophysiology of Kartagener syndrome?

Answer 5

Causes defective cilia due to dynein protein in the cilia not working. It is also associated with situs inversus.

Question 6

Explain the formation of the diaphragm.

Answer 6

1. 5th week: the septum transversum, a think mass of cranial mesenchime, that gives rise to the thoracic diaphragm, and the anterior mesentary of the foregut in the adult. After it’s decent, it will merge with the growing pleural peritoneal membranes, also merging with the dorsal mesentary of the esophagus, and also merge with the growing muscles of the abdomial wall.

Question 7

What is a diaphragmatic hernia?

Answer 7

Abdominal structures enter thorax. The resulting compression of the organs can lead to lung hypoplasia, most often on the left side. This is associated with polyhydramnios.

Question 8

What is the clinical presentation of a severe diaphragmatic hernia on birth?

Answer 8

A recently born with:

1. Flattened abdomen.
2. Cyanosis.
3. Inability to breathe.

Question 9

What are the presentations of diaphragmatic hernia and which is the most common?

Answer 9

1. Sliding hiatal hern. (the hour-glass shaped) (more common).
2. Paraesophageal hiatal hernia.

Question 10

What nerves innervate the diaphragm?

Answer 10

[C3, 4, 5 keeps the diaphragm alive].

Innervated by the phrenic nerve: C3, C4, C5.

Question 11

Why does irritation to the diaphragm presents as shoulder and/or neck pain?

Answer 11

Because the growing diaphragm is going to drag that phrenic nerve down from the cervical region into the thoracic region.

Question 12

What structures transverse the diaphragm?

Answer 12

[ I ate ten eggs at twelve ].

1. At T8: The inferior vena cava (IVC).
2. At T10: Esophagus and Vagus nerve.
3. at T12: Aorta, Azygos vein, Thoracic duct.

Question 13

What are the four embryological structures that make up the diaphragm?

Answer 13

1. Septum transversum.
2. Pleuroperitoneal membranes.
3. Dorsal mesentery of the esophagus.
4. Abdominal wall muscles.

Question 14

What muscles are used in normal quite breathing?

Answer 14

Diaphragm does almost all the work during inspiration.

Expiration is achieved passively as the diaphragm relaxes.

Question 15

What muscles are used for breathing and exhaling during excersice?

Answer 15

Inspiration:

1. Diaphragm.
2. Sternocleidomastoids.
3. External intercostals.
4. Scalene muscles.

Exhale:

1. Transversus abdominis.
2. rectus abdominis.
3. Internal and external obliques.
4. Internal intercostals.

Question 16

What are the conducting zones of airway zones AKA anatomic dead space?

Answer 16

1. Nose and pharynx.
2. Trachea.
3. Bronchi.
4. Bronchiole.
5. Terminal bronchiole.

Question 17

What are the respiratory zones of the airway zones.

Answer 17

1. Respiratory bronchiole.
2. Alveolar duct.
3. Alveolar sac.

Question 18

What is the physiologic dead space of the respiratory system?

Answer 18

It is the anatomic dead space (the conducting zone) plus the zones that are no longer involved in respiration due to pathology in the respiratory zone.

Question 19

Which lung has three lobes and which one has two?

Answer 19

Right lung has three lobes: Superior, middle and inferior lobes.
Left lung has superior and inferior lobes.

Question 20

What separates the superior lobe from the middle lobe in the right lung?

Answer 20

Horizontal fissure.

Question 21

What separates the middle lobe from the inferior lobe in the right lung?

Answer 21

Oblique fissure.

Question 22

Where are the cardiac notch and Lingula located?

Answer 22

They are located in the interior borders of the left lung.

Question 23

Why is the right lung more susceptible for inhaled foreign bodies to end up at?

Answer 23

Because the right mainstem bronchus is both wider and more vertical then the left mainstem bronchus.

Question 24

What is a bronchopulmonary segment and what are the components?

Answer 24

Each of the terciary bronchi serves as a bronchopulmonary segment. It is made up of:

1. Bronchus.
2. Two arteries: Pulmonary artery and Bronchial artery.

Question 25

How many broncopulmonary segments are there one each side and how are they grouped?

Answer 25

There are 10 on the right:

1. Superior lobe (3): B1-B3.
2. Middle lobe (2): B4, B5.
3. Inferior lobe (5): B6-B10

There are 8-10 segments on the left lung.
Upper lobe (4-5): B1-B5.
Lower lobe (4-5): B6-B10.

Each segment is separated from the others by a layer of connective tissue, meaning that each broncopulmonary segment is a discrete anatomical and functional unit, so it can be surgically removed without disturbing the others.

Question 26

What are Type I pneumocytes?

Answer 26

They are simple squamous epithelial cells (flat). They are > 97% of alveolar surface. Critical to gas exchange, cannot replicate, and are highly sensitive to toxic insults.

Question 27

What are Type II pneumocytes?

Answer 27

They are larger, cuboidal in shape. Found at the alveolar-septal junction, and cover about 3% of alveolar surface. Their primary function is to secrete pulmonary surfactant called dipalmitoyl phosphatidylcholine: it decreases alveolar surface tension.

They can replicate and replace type I pneumocytes.

Question 28

What is the Lecithin: Sphingomyelin?

Answer 28

Take a sample of amniotic fluid to determine the maturity of the lungs. A ration of greater than 2.0 in amniotic fluid indicates fetal lung maturity.

Question 29

What can be given to the mother to mature the lungs of the fetus?

Answer 29

Give her corticosteroids.

Question 30

What cell type proliferates during cell damage in the alveoli?

Answer 30

Type II pneumocytes.

Question 31

A young woman has infertility, recurrent URIs, and dextrocardia. What protein is defective?

Answer 31

Dynein. She has Kartagener syndrome.

Question 32

RFF: Chronic sinusitis, infertility and situs inversus.

Answer 32

Kartagener syndrome.

Question 33

What is the most common type of tracheoesophageal fistula?

Answer 33

Esophageal atresia, around 85% of cases, it is when the esophagus ends in a blind pouch; the lower esophagus connects to the trachea itself.