Embryology

Question 1

upper respiratory tract composed of

Answer 1

• nose
• oral cavity
• pharynx
• upper larynx

Question 2

lower respiratory tract composed of

Answer 2

• lower larynx
• trachea
• bronchi
• bronchioles
• alveoli

Question 3

goal of respiratory tract

Answer 3

• conduct air

- gas exchange with the blood

Question 4

further breakdown of lower respiratory tract

Answer 4

• primary bronchus
• secondary bronchus
• tertiary bronchus
• terminal bronchiole

Question 5

gases are exchanged between

Answer 5

• blood in capillaries

- air in alveoli

Question 6

gas exchange requires that alveoli have

Answer 6

• alveoli have thin walls

Question 7

what type of epithelium is found in the lower respiratory tract

why is this important

Answer 7

• simple squamous

- thin so it allows for gas exchange

Question 8

alveolar lumens are lined by

Answer 8

• surfactant

Question 9

surfactant is secreted by

Answer 9

• type 2 pneumocytes

Question 10

role of surfactant

Answer 10

• keeps alveolar surface tension low so that thin-walled alveoli don’t collapse

Question 11

what are collapsed alveoli called

Answer 11

• atelectasis

Question 12

what can atelectasis cause

Answer 12

• respiratory distress

Question 13

trachea and lung develops from which germ layer

Answer 13

• endoderm

Question 14

the lower respiratory tract arises as an _______ of the _____

Answer 14

• anterior diverticulum

- of the GI tract (specifically the pharynx)

Question 15

what is a diverticulum?

Answer 15

• a blind tube arising from a cavity or tube

Question 16

when does the trachea and lung form?

Answer 16

• during week 4

Question 17

why does the anterior diverticulum make sense?

Answer 17

• because it forms anterior to the esophagus

Question 18

in what direction does the lower respiratory tract develop?

Answer 18

• cranial to caudal

Question 19

what are the most caudal structures?

Answer 19

• alveoli

Question 20

what are the last structures to form?

Answer 20

• alveoli

Question 21

is there any respiratory function (gas exchange) in-utero?

where does it occur?

Answer 21

• no

- occurs in the placenta

Question 22

importance of fetus respiratory movements

Answer 22

• bring amniotic fluid in and out of developing respiratory tree
• necessary for lung development

Question 23

placenta formed by

Answer 23

• the embryo

Question 24

what does the maternal blood release into the placenta?

where does it go?

Answer 24

• nutrients and O2

- goes into the fetal blood

Question 25

what does the fetal blood release into the placenta? where does it go?

Answer 25

- releases CO2 and wastes | - goes into the maternal blood

Question 26

placenta functions as

Answer 26

- fetal lungs, kidney, and GI tract

Question 27

what does the fetus "breathe"

Answer 27

- amniotic fluid (not air)

Question 28

post-natal breathing requires when must this be accomplished?

Answer 28

- alveoli are formed - alveoli have thin walls - alveoli secrete surfactant to keep them open - this must be accomplished by birth

Question 29

a term fetus is how many weeks?

Answer 29

- 38 weeks

Question 30

a term fetus normally has adequate amounts of ________ alveoli

Answer 30

- mature, thin-walled

Question 31

a term fetus normally has adequate amounts of ______ for breathing air

Answer 31

- surfactant

Question 32

what happens at week 22?

Answer 32

- primitive, thick walled alveoli begin to develop

Question 33

when do the last alveoli develop

Answer 33

- around 7 years old

Question 34

when is surfactant produced?

Answer 34

- around week 24

Question 35

over time the thick alveolar walls become ____

Answer 35

- thin

Question 36

over time increasing numbers of ______ develop

Answer 36

- air sacs

Question 37

over time _________ production increases

Answer 37

- surfactant

Question 38

in a premature infant, viability is partially dependent on the ability to which requires

Answer 38

- breath air | - requires adequate quantities of surfactant

Question 39

what happens if surfactant is deficient

Answer 39

- infant respiratory destress syndrome may develop

Question 40

what can be used in premature infants while lungs continue to develop after birth?

Answer 40

- artificial surfactant

Question 41

how many weeks before the baby is due defines prematurity

Answer 41

- at least 3

Question 42

tracheoesophageal fistula arises in what weeks?

Answer 42

- 4-7

Question 43

tracheoesophageal fistula most common type

Answer 43

- type C

Question 44

tracheoesophageal fistula clinical symptoms in utero

Answer 44

- polyhydramnios - excessive amniotic fluid

Question 45

tracheoesophageal fistula clinical symptoms after birth

Answer 45

- choking - coughing - cyanosis - vomiting

Question 46

embryonic lung development period in which weeks what occurs

Answer 46

- 3-8 | - bronchi and bronchioles form

Question 47

pseudoglandular lung development period in which weeks what occurs

Answer 47

- 5-16 | - bronchioles branch into terminal bronchioles

Question 48

canicular lung development period in which weeks what occurs

Answer 48

- 16-26 | - terminal bronchioles branch into respiratory bronchioles

Question 49

saccular lung development period in which weeks what occurs

Answer 49

- 26-38 (birth) | - alveolar ducts form

Question 50

alveolar lung development period in which weeks what occurs

Answer 50

- 36-38 and even further after birth | - alveolar sacs form