Respiratory Zone

Question 1

What is the function of the acinus?

Answer 1

gas exchange

Question 2

The acinus extends from the ______ to the ______

Answer 2

respiratory bronchiole, alveolus

Question 3

The acinus includes: (4)

Answer 3

1. Respiratory bronchioles
2. Alveolar ducts
3. Alveolar sacs
4. Alveoli

Question 4

The acinus is also known as a(n):

Answer 4

lobule

Question 5

The respiratory bronchioles are distal to the:

Answer 5

terminal bronchioles

Question 6

Purposes of the respiratory bronchioles:

Answer 6

1. Conducting airway

2. Transitional airway&raquo_space; some gas exchange

Question 7

What structure has occasional budding alveoli?

Answer 7

respiratory bronchioles

Question 8

The alveolar ducts arise from the ________

Answer 8

respiratory bronchioles

Question 9

The alveolar ducts have a ________ structure

Answer 9

tube-like

Question 10

The walls of the alveolar ducts are made up of:

Answer 10

many alveoli

Question 11

Approximately ___% of gas exchange occurs at the alveolar ducts

Answer 11

35%

Question 12

Alveolar sacs are clusters of (#) alveoli

Answer 12

10-16

Question 13

____% of gas exchange occurs at the alveoli

Answer 13

65%

Question 14

There are (#) alveoli in total

Answer 14

300 million

Question 15

There are (#) capillary segments per alveolus

Answer 15

1000

Question 16

Surface area of the alveoli/capillaries is:

Answer 16

50-100 m^2

Question 17

What are Pores of Kohn?

Answer 17

openings between the type 1 alveolar epithelial cells

Question 18

What is the purpose of the Pores of Kohn?

Answer 18

allow for collateral ventilation so alveoli don’t collapse

Question 19

What may cause Pores of Kohn to increase in number and size?

Answer 19

disease

Question 20

Overall thickness of the A/C membrane:

Answer 20

0.5 micrometers

Question 21

Three parts of the A/C membrane:

Answer 21

1. Alveolar epithelium
2. Interstitium/Basement membrane
3. Capillary endothelium

Question 22

Tight junction:

Answer 22

tight area between alveolar type 1 cells

Question 23

Loose junction:

Answer 23

endothelial capillary cell junctions

Question 24

Type 1 alveolar epithelial cells are: (structural description - 3 points)

Answer 24

flat and thin with long cytoplasmic extensions

Question 25

95% of the alveolar surface is made of:

Answer 25

type 1 alveolar epithelial cells

Question 26

Purpose of the type 1 alveolar epithelial cells:

Answer 26

gas exchange

Question 27

Type 2 alveolar epithelial cells are _____ than type 1

Answer 27

fatter

Question 28

Type 2 alveolar epithelial cells are located:

Answer 28

interspersed among type 1 cells

Question 29

Type 2 alveolar epithelial cells contain: (2)

Answer 29

1. microvilli | 2. lamellar bodies

Question 30

Microvilli description and function:

Answer 30

blunt-like projections, increase SA for diffusion

Question 31

Lamellar bodies are found:

Answer 31

in the cytoplasm

Question 32

Function of lamellar bodies: (2)

Answer 32

produce surfactant and lysosomal enzymes

Question 33

Surfactant is found in the:

Answer 33

Alveolar fluid layer

Question 34

Surfactant is produced and recycled by:

Answer 34

type 2 alveolar cells

Question 35

Surfactant is made up of: (2)

Answer 35

90% phospholipids, 10% proteins

Question 36

Primary phospholipid in surfactant:

Answer 36

lecithin

Question 37

At what age does lecithin begin to appear in significant amounts?

Answer 37

35 weeks gestation

Question 38

What is the L/S ratio?

Answer 38

Lecithin/Sphingomyelin

Question 39

Primary purpose of surfactant:

Answer 39

Reduce surface tension (ST)

Question 40

Type 3 alveolar macrophages are _____ cells

Answer 40

migratory

Question 41

Type 3 alveolar macrophages have _______ action (2)

Answer 41

phagocytic and lymphocytic

Question 42

Lymphocytic action of the type 3 alveolar macrophages can:

Answer 42

cause destruction of elastin and collagen fibers

Question 43

The interstitium consists of: (3)

Answer 43

1. Interstitial fluid 2. Collagen 3. Elastin

Question 44

Purposes of the interstitium: (3)

Answer 44

1. Gives shape and structure to the alveoli 2. Prevents over-distension of alveoli 3. Absorbs fluid from vasculature via lymphatics

Question 45

The pulmonary capillary endothelium is made of _____ cells

Answer 45

simple squamous

Question 46

The pulmonary capillary endothelium is very ______ and allows _______

Answer 46

leaky, fluid and/or substances to pass into the interstitium

Question 47

Endothelial cells have ______ called ________

Answer 47

cavities, caveolae