Chapter 6: Alveolar Ducts - Clinical Aspects

Question 1

What are the general functions of alveolar ducts?

Answer 1

Gas exchange

Question 2

What are the general functions of alveolar sacs?

Answer 2

Gas exchange

Question 3

What are the general functions of alveoli?

Answer 3

Gas Exchange (lol)

Question 4

What is the epithelium of Alveolar Cell Type I (Type I Pneumocyte)? General function?

Answer 4

Squamous with zonula occludens between cells

Question 5

What alveolar cell type makes up the majority of the alveolar surface?

Answer 5

Type I

Question 6

What is the epithelium of Alveolar Cell Type II (Type II Pneumocyte)? Where is type II found?

Answer 6

Cuboidal cells

Found on sides between alveoli

Question 7

What are the 3 general functions of Type II Pneumocytes?

Answer 7

1. Produce pulmonary surfactant
2. Produce lysozymes
3. Stem cell for Alveolar Type I/II

Question 8

What is a dust cell?

Answer 8

An alveolar macrophage that develops from monocytes

Question 9

What are the general functions of a dust cell?

Answer 9

Clean septal wall using phagocytosis

Produce lysozyme

Question 10

What do you call the region between two alveoli?

Answer 10

Interalveolar Septum

Question 11

What parts can we find in the interalveolar septum?

Answer 11

Alveolar type I & II cells
Continuous capillaries
Fibroblasts
Basal Lamina
Small amounts of CT with many elastic fibers

Question 12

What is the blood-gas barrier?

Answer 12

Region where O2/CO2 pass between the air and the blood

Question 13

What are the 4 parts of the blood-gas barrier in order from air to blood? (note: she will ask the exact order so know that shit)

Answer 13

1. Pulmonary surfactant (begins with alveoli)
2. Alveolar type I cell
3. Fused basal lamina: shared between alveolar type I cell & endothelial cell of capillary
4. Endothelial cell of capillary

Question 14

What is the function of the blood-gas barrier?

Answer 14

Provides the most efficient gas exchange (it is important to keep the distance small)

It is the minimum diffusion distance/barrier that allows for the most efficient gas exchange

Question 15

Which ganglion provides fibers to relax bronchial smooth muscle?

Answer 15

Thoracic sympathetic chain ganglion - results in bronchidilation.

Question 16

Which fibers constrict pulmonary blood vessels by stimulating the smooth muscle in the tunica media?

Answer 16

Sympathetic

Question 17

The vagus nerve provides what type of fibers that lead to bronchconstriction?

Answer 17

Parasympathetic (constricts bronchial smooth muscle)

Don’t get this confused with pulmonary blood vessels!

Question 18

In chronic exposure to irritants, what causes in increase in mucus and fluid?

Answer 18

Increase in seromucous glands and goblet cells

Question 19

What causes congestion in chronic exposure to irritants?

Answer 19

Decrease in ciliated columnar cells

Question 20

What replaces respiratory epithelium due to excessive coughing?

Answer 20

Stratified squamous epithelium

Question 21

What is another name for Respiratory Distress of Newborns (RDS)?

Answer 21

Hyaline Membrane Disease

Question 22

What is the cause of RDS?

Answer 22

Too few mature alveolar type II cells

Question 23

What are the two treatments for hyaline membrane disease?

Answer 23

1. Artificial surfactant and CPAP (only a few treatments needed)
2. Glucocorticoids given before birth

Question 24

How does emphysema effect alveolar elasticity?

Answer 24

Decrease in elastin so decrease in elasticity. There’s also a reduced surface for gas exchange.

Question 25

T/F: Emphysema is reversible.

Answer 25

False

Question 26

What are the two common causes of emphysema?

Answer 26

1. Inflammation due to smoking or infection - attracts macrophages & neutrophils which secrete elastase 2. Genetics - usually HOMOzygous dominant. Hepatocytes produce alpha 1-AT but can't release it.

Question 27

Which type of lung cancer is often seen in non-smokers? Where does this cancer develop?

Answer 27

Adenocarcinoma Develops from epithelium in alveoli and bronchioles

Question 28

Which type of lung cancer is the least common but highly malignant? What types of cells does it develop from?

Answer 28

Small cell carcinoma Develops from small granule DNES cells in bronchi

Question 29

Which type of lung cancer has a strong link to smoking? Where does this cancer develop?

Answer 29

Squamous cell carcinoma Epithelium in Segmental bronchi

Question 30

What is the name of a protein that protects elastic fibers?

Answer 30

Alpha 1-AT (antitrypsin)

Question 31

What cell produces Alpha 1-AT?

Answer 31

Hepatocytes

Question 32

What irritant inactivates alpha 1-AT?

Answer 32

Free radicals in cigarette smoke

Question 33

IC: Which cell type is not fully functional in adequate numbers in pre-mature infants born with RDS?

Answer 33

Alveolar Type II

Question 34

IC: Alpha-1AT is produced by ____ and protects ____ fibers in the lungs.

Answer 34

Hepatocytes | Elastic