E: Respiratory

Question 1

The respiratory diverticulum appears during week __

Answer 1

4

Question 2

The respiratory diverticulum appears as an outgrowth of ___

Answer 2

foregut

Question 3

The respiratory diverticulum is ___ derived

Answer 3

endoderm

Question 4

Because respiratory diverticulum is endoderm derived, what adult structures are endoderm derived?

Answer 4

inner lining of larynx, trachea, bronchi, lungs

Question 5

The lung bud grows out into the ____

Answer 5

splanchnic mesoderm

Question 6

Because lung bud grows into splanchnic mesoderm, what adult structures are splanchnic mesoderm derived?

Answer 6

cartilageinous, musculature, connective tissue of trachae and lungs

Question 7

The lung bud initially has an open communication with ___

Answer 7

foregut

Question 8

Which direction does the lung bud grow?

Answer 8

caudal

Question 9

As the lung bud grows caudally, what forms?

Answer 9

tracheoesophageal ridges

Question 10

Tracheoesophageal ridges separate ____

Answer 10

the lung bud from the foregut

Question 11

When tracheoesophageal ridges fuse, it becomes ___

Answer 11

tracheoesophageal septum

Question 12

Tracheoesophageal septum:
dorsal part = ____
ventral part = ___

Answer 12

dorsal part = esophagus

ventral part = laryngotracheal tube (lung bud + trachae)

Question 13

What is the laryngotrachael tube?

Answer 13

early in development when lung bud and trachea are still together

Question 14

Tracheoesophageal septum can lead to what 2 main developmental disorders?

Answer 14

1. esophageal atresia

2. tracheoesophageal fistula

Question 15

What is esophageal atresia?

Answer 15

complete septation of the esophagus

blind end sac

food has nowhere to go

Question 16

What is a tracheoesophageal fistula?

Answer 16

connection between tracheo and esophagus

so food and air are going t o the wrong places

Question 17

If you have esophageal atresia, do you automatically have tracheoesophageal fistulas?

Answer 17

no

you can have esophageal atresia with or without tracheoesophageal fistulas

Question 18

The lung bud maintains communication with pharynx through ___

Answer 18

laryngeal orifice

Question 19

The lung bud maintains communication with ___ through the laryngeal orifice

Answer 19

pharynx

Question 20

Describe the shape of the laryngeal orifice

Answer 20

initially is a SAGITTAL SLIT

changes into a T SHAPED opening

Question 21

Larynx cartilage and musculature is derived from pharyngeal arches ___

Answer 21

4 and 6

Question 22

Mesenchyme of pharyngeal arches 4 and 6 become _____ in the larynx

Answer 22

thyroid cartilage
cricoid cartilage
arytenoid cartilage

Question 23

The epiglottis is formed from mesenchyme of the ____

Answer 23

caudal hypopharyngeal eminence

Question 24

hypopharyngeal eminence

• where is it
• what does it become

Answer 24

@ base of tongue

mesenchyme = becomes EPIGLOTTIS

Question 25

Laryngeal mm from pharyngeal arch 4 is innervated by ____ Laryngeal mm from pharyngeal arch 6 is innervated by ____

Answer 25

4 = superior laryngeal n 6 = recurrent laryngeal n

Question 26

At day __ lung bud divides into 2 primary bronchial buds

Answer 26

28

Question 27

At day 28 the lung bud divides into ___

Answer 27

2 primary bronchial buds

Question 28

At week __, the R/L primary bronchial buds divide

Answer 28

5

Question 29

At week 5, the R/L primary bronchial buds divide into ___

Answer 29

right = 3 secondary bronchial buds left = 2 secondary bronchial buds

Question 30

At week __, the R/L secondary bronchial buds divide

Answer 30

5-6

Question 31

Week 5-6, the R/L secondary bronchial buds divide into ___

Answer 31

right = 10 tertiary bronchial buds left = 8 tertiary bronchial buds

Question 32

Once it starts to divide, the lung bud is growing in which direction?

Answer 32

caudal and LATERAL

Question 33

The lung bud is growing laterally into ___

Answer 33

pericardioperitoneal canal

Question 34

How does the shape of the pericardioperitoneal canal change? What does this become?

Answer 34

It narrows Becomes thep leural cavities

Question 35

Splanchnic mesoderm becomes ___ Somatic mesoderm becomes ___

Answer 35

splanchnic -- visceral somatic -- parietal

Question 36

The respiratory tree produces small branches called ___

Answer 36

terminal bronchioles

Question 37

At week ___ the terminal bronchioles divide

Answer 37

16-28

Question 38

At weeks 16-28, the terminal bronchioles divide into ____

Answer 38

2 or more respiratory bronchioles

Question 39

What is so significant about the change from terminal bronchioles to respiratory bronchioles?

Answer 39

this is the transition period from CONDUCTING to RESPIRATORY

Question 40

By week ___ terminal sacs (primitive alveoli) are formed

Answer 40

36

Question 41

What are the 4 stages of branching?

Answer 41

1. psuedoglandular period 2. canalicular period 3. terminal sac period 4. alveolar period

Question 42

Which of the stages of branching are fetal vs. neonatal?

Answer 42

fetal = psuedoglandular, canalicular, terminal sac late fetal/neonatal = alveolar

Question 43

Which of the stages of branching would a fetus survive?

Answer 43

fatal = psuedoglandular and canalicular could survive w/ assistance = termianl sac period survive = alveolar

Question 44

Psuedogladnular period - when? - what is present?

Answer 44

5-16 weeks | branching continues to form TERMINAL BRONCHIOLES

Question 45

Canalicular period - when? - what is present?

Answer 45

16-26 weeks | each terminal bronchiole divided into 2+ respiratory bronchioles which divides into 3-6 alveolar ducts

Question 46

Terminal sac period - when? - what is present?

Answer 46

26 weeks terminal sacs (primitive alveoli) are formed capillaries establish close contact

Question 47

Alveolar Period - when? - what is present?

Answer 47

8months - early childhood | mature alveoli have well developed epithelial-endothelial contact

Question 48

Describe the epithelium at 26 weeks of the terminal sacs in respiratory system?

Answer 48

mostly simple squamous cells = type 1 alveolar cells a few type 2 alveolar cells (surfactant)

Question 49

Describe type 1 alveolar cells

Answer 49

simple squamous cells that line terminal sacs makes up most of epithelium

Question 50

Describe type 2 alveolar cells

Answer 50

scattered among type 1 alveolar cells these produce, store, secrete pulmonary surfactant

Question 51

Where is surfactant present?

Answer 51

forms film over internal walls of alveolar sacs

Question 52

What is the function of surfactant?

Answer 52

counteracts surface tension facilitates expansion of terminal sacs by preventing lung collapse

Question 53

What is atelectasis?

Answer 53

lung collapse

Question 54

Production of surfactant occurs at weeks ___

Answer 54

20-22