Unit III: Respiratory System

Question 1

The ___ mesoderm will form the cartilages and smooth muscle of the larynx, trachea, and bronchi

Answer 1

Splanchnic

Question 2

Divisions of the laryngotracheal diverticulum

Answer 2

1. ventral part

2. dorsal part

Question 3

What makes up the ventral part of the laryngotracheal diverticulum?

Answer 3

Larynx, trachea, bronchi, lungs

Question 4

What makes up the dorsal part of the laryngotracheal diverticulum?

Answer 4

Esophagus

Question 5

All laryngeal cartilages except for the ___ develops from the 4th-6th pharyngeal arches

Answer 5

Epiglottic cartilage

Question 6

The cricothyroid muscle develops from the ___ pharyngeal arch

Answer 6

Fourth

Question 7

All muscles of the larynx except the cricothyroid are supplied by the ___

Answer 7

Recurrent laryngeal nerve

Question 8

The cricothyroid muscle is supplied by the ___

Answer 8

Vagus nerve

Question 9

At what ages in a human is the larynx in a high position?

Answer 9

0-1

Question 10

___ mesoderm forms the C-rings and the smooth muscle of the trachea

Answer 10

Splanchnic

Question 11

What is splanchnic mesoderm?

Answer 11

Visceral-> relating to internal organs

Question 12

What is somatic mesoderm?

Answer 12

Related to the body wall

Question 13

What is tracheoesophageal fistula?

Answer 13

1. abnormal opening between the trachea and the esophagus
2. from incomplete fusion of the tracheoesophageal folds
3. esophageal atresia
4. upper esophagus is a blind pouch
5. infants cannot swallow
6. requires surgery

Question 14

The upper division of the bronchus becomes the ___

Answer 14

Superior lobar bronchus

Question 15

The lower division of the bronchus becomes the ___

Answer 15

Middle and inferior lobar bronchi

Question 16

How many segmental bronchi are in each lung?

Answer 16

10

Question 17

As the lung develops, the splanchnic mesoderm on its ___ surface forms the visceral pleura

Answer 17

Outer

Question 18

The somatic mesoderm covering the inside of the ___ forms the parietal pleura

Answer 18

Thoracic wall

Question 19

What is the space called between the parietal and visceral pleura?

Answer 19

Pleural cavity

Question 20

4 stages of lung development

Answer 20

1. pseudo glandular
2. cancalicular
3. terminal sac
4. alveolar

Question 21

When is the pseudoglandular stage?

Answer 21

6-16 weeks

Question 22

When is the canalicular stage?

Answer 22

16-26 weeks

Question 23

When is the terminal sac stage?

Answer 23

26 weeks-birth

Question 24

When is the alveolar stage?

Answer 24

32 weeks-8 years

Question 25

Can a premature infant survive at the pseudoglandular stage?

Answer 25

No

Question 26

Can a premature infant survive at the canalicular stage?

Answer 26

Possibly- some gas exchange can occur, but the infant requires intensive care and mortality rate is high

Question 27

Can a premature infant survive at the terminal sac stage?

Answer 27

Possibly- intensive care is needed due to insufficient lung surfactant

Question 28

What are type 1 pneumocytes?

Answer 28

Squamous epithelial cells in the walls of the terminal sacs

Question 29

What is the function of type 2 pneumocytes?

Answer 29

Secretes surfactant

Question 30

What is the purpose of surfactant?

Answer 30

Reduces tension between the air and alveolar surfaces-> allows expansion during expiration

Question 31

When does adequate levels of surfactant reach?

Answer 31

26-28 weeks

Question 32

What is the pseudoglandular stage characterized by?

Answer 32

Branching of bronchioles and formation of bronchopulmonary segments

Question 33

What is the canalicular stage characterized by?

Answer 33

1. expansion in diameter of bronchi 2. vascularization of the lung 3. formation of respiratory bronchioles and alveolar ducts

Question 34

What is the terminal sac stage characterized by?

Answer 34

Formation of numerous terminal sacs-> primordial of the alveoli

Question 35

What is the alveolar stage characterized by?

Answer 35

Development of mature alveoli

Question 36

What 3 factors determine if a premature infant will be able to exchange gases successfully?

Answer 36

1. adequate surfactant 2. formation of functional alveoli 3. establishment of pulmonary/systemic circulation

Question 37

Fetal breathing movements function to:

Answer 37

1. exercises the muscles of respiration | 2. stimulate lung development

Question 38

T/F: the lungs are completely filled with amniotic fluid at birth

Answer 38

False- half filled-> must be removed to allow inflation of the lungs

Question 39

How do you clear the amniotic fluid from the lungs?

Answer 39

1. expulsion through the mouth and nose during birth 2. via pulmonary blood vessels 3. via pulmonary lymphatics

Question 40

T/F: pulmonary lymphatic vessels are larger and more numerous in the fetus than in the adult

Answer 40

True

Question 41

3 factors that are essential for normal lung development

Answer 41

1. adequate thoracic volume 2. adequate amniotic fluid 3. fetal breathing movements

Question 42

What is oligohydramnios and pulmonary hypoplasia?

Answer 42

1. insufficient amniotic fluid is present 2. restricts lung expansion 3. underdevelopment of the lungs

Question 43

What is respiratory distress syndrome?

Answer 43

1. rapid, labored breathing after birth 2. affects 2% of neonates 3. caused from surfactant deficiency