Overview of the Pulm System/Lung Development

Question 1

Functions of the lung

Answer 1

1) gas exchange= constantly survey in and out environ
1) extraction of O2 from enviro
2) eliminate CO2 from lungs
3) endocrine and immune organ

Question 2

Proper gas exchange requires which organs

Answer 2

1) lung, chest wall, resp muscles for movement
2) heart and pulm circulation for flow
3) central and peripheral receptors to control and match ventilation/perfusion

Question 3

problem in obstructive airway disease

Answer 3

1) impede gas flow in and out of alveoli

Question 4

problem in restrictive disease

Answer 4

alter ventilation-perfusion matching

barrier for gas exchange

Question 5

problem in pulmonary vascular disease

Answer 5

impair gas transfer

–> right heart failure

Question 6

Pleural space created by (2)

Answer 6

1) inner lining of chest wall (parietal pleura)

2) outer lining of lung
(visceral pleura

Question 7

what separates pleura

Answer 7

thin fluid (lubricant)

Question 8

what happens if air enters pleural space

Answer 8

pneumothorax

Question 9

what happens if fluid enters pleural space

Answer 9

pleural effusion

Question 10

where are 5 lobes

Answer 10

2 upper lobe

2 lower lobe

right middle lobe

Question 11

what supplies lobes

Answer 11

lobar bronchi and pulm arteries

Question 12

what do pulm veins and lymphatics drain from

Answer 12

drain from the acini

Question 13

which structures are part of lung’s conducting airways

Answer 13

1) trachea
2) bronchi
3) bronchioles

Question 14

which structures part of lung’s gas exchange units

Answer 14

1) respiratory bronchioles
2) alveolar ducts
3) alveoli

Question 15

conducting airway is defined by a series of ___

Answer 15

dichotomously branching tubes

Question 16

the first 16 of the 23 airways are ___

Answer 16

conducting (conduit for gas transfer to and from respiratory exchange units)

Question 17

structures that make up airway wall

Answer 17

1) inner mucosal surface (epithelial cells, cilia, goblet)
2) smooth muscle layer
3) outer connective tissue layer

Question 18

what are structures within inner mucosal surface

Answer 18

1) epithelial cells
2) cilia
3) goblet cells

Question 19

___ changes as generation increases

Answer 19

morphology of the airway wall

Question 20

how does airway wall morphology change from bronchi to bronchioles

Answer 20

loss of cartilage in outer tissue layer

Question 21

what do bronchitis and bronchietasis refer to

Answer 21

diseases of airway with cartilage

Question 22

what do bronchiolitis refer to

Answer 22

diseases of bronchioles or non-cartilagenous airways

Question 23

ventilation

Answer 23

air movement in and out of lung

Question 24

respiration

Answer 24

gas exchange

exchange O2 and CO2 across alveolar capillary movements

Question 25

conducting airways do not ___

Answer 25

exchange gas "anatomic deadspace"

Question 26

what does deadspace refer to?

Answer 26

parts of lungs that don't exchange gas

Question 27

What are the gas exchange regions

Answer 27

allow efficient diffusion of O2 and CO2 across alveolar and capillary walls

Question 28

what is the gas exchange region also known as

Answer 28

acinus

Question 29

where does acinus begin?

Answer 29

1) distal to terminal bronchiole

Question 30

what are components within gas exchange region

Answer 30

1) respiratory bronchiole 2) alveolar ducts 3) alveoli

Question 31

2 different cell types in alvoelar epithelial cells

Answer 31

1) squamous lining cells = type 1 cells = pneumocytes (simple squamous) 2) secretory cells = type II cells

Question 32

describe type 1 cells of lung

Answer 32

95% of alveolar surface area fuse with capillary endothelium to create thin membrane for transfer

Question 33

what do type 1 cells fuse to create?

Answer 33

capillary endothelium to create thin membrane for gas transfer

Question 34

what cells are injured in ARDS

Answer 34

type 1 cells

Question 35

if type 1 cells are injured what disease

Answer 35

ARDS

Question 36

functions of type II cells

Answer 36

1) repair/replace injured type 1 pneumocytes | 2) secrete surfactant (lower alveolar surface tension)

Question 37

what do type II cells secrete

Answer 37

surfactant (lower alveolar surface tension

Question 38

pulmonary arteries (and arterioles) run with the ___

Answer 38

bronchi (and bronchioles) PULMONARY VEINS ARE MORE PERIPHERAL

Question 39

at what interface does gas exchange occur

Answer 39

across capillary-alveolar interface

Question 40

where do lymphatics run? what is their function?

Answer 40

run near pulm arteries and veins help with extravascular lung water

Question 41

lung development what do lungs develop from? when? fxn of that structure

Answer 41

lung bud of gut tube endoderm at week 4 from outpouch between 4th and 6th brachial arches (laryngotracheal groove) instructs formation of notochord, heart, blood vessel creates 2 tubes- digestive & respiratory

Question 42

which layer do lungs develop from?

Answer 42

gut endoderm

Question 43

where does pulmonary circulation develop from?

Answer 43

surrounding mesenchyme off lung bud branching

Question 44

what happens day 26- 6 weeks | embryonic

Answer 44

foregut endoderm invade splanchnic mesenchyme 3 rounds of branching --> lung lobes (asymmetric --> dichotomous (proximal tracheobronchial tree) --> subsegmental bronchii --> fill bilateral pleural cavities

Question 45

____ forms lung lobes

Answer 45

3 rounds of branching

Question 46

when does this happen foregut endoderm extends into surrounding mesenchyme 3 rounds of branching --> lung lobes

Answer 46

days 26- 6 weeks

Question 47

what happens 6 to 16 weeks | pseudoglandular

Answer 47

lung descend into thorax pleuroperitoneal foramen closens 14 rounds of branching form terminal bronchioles glandular cells = columnar rather than glandular finished formation of conducting airways (down to #16) --> splanchnic mesenchyme --> forms cartilage, smooth muscle cells and mucous glands

Question 48

when does this happen 14 rounds of branching form terminal bronchioles

Answer 48

6 - 16 weeks

Question 49

what happens between 16-28 weeks (canalicular)

Answer 49

form terminal bronchiole that divides into 2+ respiratory bronchioles develop pulm capillary bed expand airspaces surfactant production begins

Question 50

when does this happen terminal bronchiole divides into 2+ respiratory bronchioles surfactant production begins

Answer 50

16-28 weeks

Question 51

what happens 28-36 weeks (saccular)

Answer 51

EPITHELIAL CELL DIFFERENTIATION --> TYPE 1 AND 2 respiratory bronchioles subdivided --> terminal sacs (develop into childhood) distal growth and branching of terminal saccules

Question 52

when does this happen respiratory bronchioles dubdivided --> terminal sacs (develop into childhood)

Answer 52

28-36 weeks

Question 53

what happens 36 week- early childhood (4-6 yrs) | alveolar

Answer 53

secondary septal form true alveoli septae thin fusion of double capillary network establish gas exchange unit

Question 54

when does this happen lung grows and alvoeli mature septae thin single capillary network in alv wall establish gas exchange unit

Answer 54

36 week to early childhood (4-6 yrs)

Question 55

what happens during week 4 of embryology

Answer 55

Epithelial cells of primitive foregut invade the splanchnic mesenchyme Primitive lung bud develops from an outpouching between the 4th and 6th brachial arches (Laryngotracheal groove)

Question 56

when does this happen? Epithelial cells of primitive foregut invade the splanchnic mesenchyme Primitive lung bud develops from an outpouching between the 4th and 6th brachial arches (Laryngotracheal groove)

Answer 56

3 weeks

Question 57

what happens during week 5 of embryology

Answer 57

right and left lung bud push into primordial pleural cavity (pericardioperitoneal)

Question 58

a

Answer 58

a

Question 59

embryonic lung branching determined by ___

Answer 59

mesoderm at branch points epithelial cell division stopped and collagen produced at developing buds, growth factor produced to induce epithelial mitosis

Question 60

when is fetal breathing detected

Answer 60

17-26 weeks gestation

Question 61

type 1 cells are fusion of ___ and ___ basal lamina

Answer 61

epithelial and endothelial

Question 62

a

Answer 62

a

Question 63

when do type II pneumocytes appear?

Answer 63

at 6 month and start secreting surfactant

Question 64

what happens during month 7

Answer 64

Respiratory bronchioles proliferate Alveolar ducts and sacs

Question 65

branching pattern determined by ___

Answer 65

mesoerm

Question 66

what happens at branch points in branching?

Answer 66

epithelial cell division stops collagen produced

Question 67

what happens at developing buds in branching?

Answer 67

growth factors produced to induce epithelial mitosis othe rmesodermal and epith factors stabilize and develop airways