2.2: The Respiratory Tract Histology

Question 1

______ is the study of the cellular anatomy of a tissue or organ that can be viewed through a microscope.

Answer 1

Histology

Question 2

What is Histology?

Answer 2

the study of the cellular anatomy of a tissue or organ that can be viewed through a microscope.

Question 3

The typical ______ (or lining of the respiratory tract) is primarily made of ciliated, pseudostratified, columnar cells.

Answer 3

respiratory epithelium

Question 4

The typical respiratory epithelium (or lining of the respiratory tract) is primarily made of what?

Answer 4

ciliated, pseudostratified, and columnar cells

Question 5

The cells of the respiratory epithelium have ___1___ at the apex or top of the ___2___.

Answer 5

1. small cilia (small hair-like projections)
2. cells (apical side)

Question 6

These cilia move or “beat” in an ___1___ motion. Their action helps to ___2___.

Answer 6

1. upward sweeping
2. keep the respiratory tract free of debris

Question 7

These cells are called ______ because they appear to be in layers.

Answer 7

pseudostratified

Question 8

Upon closer examination, all the cells of the respiratory epithelium attach to the ______ of the epithelial tissue.

Answer 8

basement membrane or “floor”

Question 9

Cells that are taller than they are wide are called what?

Answer 9

columnar

Question 10

columnar means what?

Answer 10

Cells that are taller than they are wide

Question 11

Goblet cells produce what?

Answer 11

Mucus

Question 12

What cell produces mucus?

Answer 12

Goblet cells

Question 13

True or False: Goblet cells (mucus producing cells) are present within the epithelium of the respiratory tract.

Answer 13

True

Question 14

Goblet cells are named for their ______.

Answer 14

wineglass (or goblet) like appearance

Question 15

Goblet Cells’ mucus helps to ___1___ within the respiratory tract, which can then be more easily removed by the ___2___.

Answer 15

1. trap debris
2. cilia

Question 16

Answer 16

Diagram of the typical cells of the respiratory epithelium

Question 17

Answer 17

Respiratory Epithelium: note the small cilia at the top (apex) of these cells

Question 18

______, much like skin, can be found at the entrance of the respiratory system.

Answer 18

Stratified squamous epithelium

Question 19

Stratified means ___1___ and squamous means ___2___.

Answer 19

1. layered
2. flattened

Question 20

___1___ means layered and ___2___ means flattened.

Answer 20

1. Stratified
2. squamous

Question 21

True or False: Stratified squamous epithelium is only found in a singular flattened layer.

Answer 21

Stratified squamous epithelium is found in multiple flattened layers.

Question 22

True or False: One example of Stratified squamous epithelium in the respiratory tract is found just inside the nostril (vestibule) of the nose.

Answer 22

True

Question 23

In the smaller bronchioles, the epithelium transitions into ______.

Answer 23

simple squamous epithelium

Question 24

Simple refers to the presence of ___1___. Simple squamous refers to ___2___.

Answer 24

1. only one layer of cells
2. a single layer of flattened cells

Question 25

The structure of the simple squamous epithelium allows for ______ to occur in the respiratory bronchioles.

Answer 25

the exchange of gasses

Question 26

The amount of goblet cells, ciliated cells, and cartilage all progressively decrease as ___1___, until all are absent at the level of the ___2___.

Answer 26

1. bronchioles become smaller and smaller
2. respiratory bronchioles

Question 27

The amount of what three things progressively decrease as bronchioles become smaller and smaller, until all they are absent at the level of the respiratory bronchioles?

Answer 27

goblet cells
ciliated cells
cartilage

Question 28

What is the primary function of the cells within the alveoli?

Answer 28

is to allow efficient exchange of gases between the air and blood.

Question 29

A lipoprotein called ______ covers the luminal surface and keeps the alveoli from sticking together during exhalation.

Answer 29

surfactant

Question 30

What is surfactant?

Answer 30

A lipoprotein that covers the luminal surface and keeps the alveoli from sticking together during exhalation.

Question 31

True or False: The walls of the alveoli are constantly kept moist with mucus.

Answer 31

False. The walls of the alveoli are constantly kept moist with WATER.

Question 32

Since water molecules are attracted to each other, the alveoli can become difficult to inflate without ______ to break up the water molecules.

Answer 32

surfactant

Question 33

Without ______ the open, circular structure of the alveoli cannot maintain their shape, making the exchange of gases difficult or impossible.

Answer 33

surfactant

Question 34

The lungs of premature babies often have not developed the ability to make ______.

Answer 34

surfactant

Question 35

What is the reason many preemies have respiratory problems after birth and need to remain hospitalized until their lungs fully develop?

Answer 35

The lungs of premature babies often have not developed the ability to make surfactant.

Question 36

Answer 36

Respiratory membrane with type I and type II alveolar cells and alveolar macrophages present. Note the surfactant lining the inner surface of the alveoli.

Question 37

What are the three major cell types of the alveoli?

Answer 37

1. type 1 alveolar cells
2. type 2 alveolar cells
3. macrophages

Question 38

What are the two epithelial cell types in the alveoli?

Answer 38

Type I and Type II alveolar cells

Question 39

Type I alveolar cells make up ___% of alveolar epithelium.

Answer 39

95%

Question 40

______ form the very thin, simple squamous epithelium of the alveoli in junction with capillaries.

Answer 40

Type I alveolar

Question 41

Type I alveolar form the very thin, ___1___ of the alveoli in junction with ___2___.

Answer 41

1. simple squamous epithelium
2. capillaries

Question 42

___1___ cells make up 5% of alveolar epithelium and are dispersed throughout the ___2___cells.

Answer 42

1. Type II alveolar
2. Type I

Question 43

One function of Type II alveolar cells is to produce and secrete pulmonary ______, which is needed throughout the alveolar surface to keep the alveoli open.

Answer 43

surfactant

Question 44

Type II cells can ___1___ to replace damaged ___2___.

Answer 44

1. divide
2. Type I cells

Question 45

Aside from Type I and Type II alveolar cells, a third type of cell found within the alveoli called ______.

Answer 45

alveolar macrophages (also known as dust cells)

Question 46

Alveolar macrophages are also known as ______.

Answer 46

dust cells

Question 47

True or False: Because of the small amount of interaction with the outside environment within the alveoli, alveolar macrophages are found in relatively small amounts.

Answer 47

False. Because of the HIGH interaction with the outside environment within the alveoli, alveolar macrophages are found in ABUNDANCE.

Question 48

Which cell is the most abundant cell within the alveoli?

Answer 48

Alveolar macrophages

Question 49

What do Alveolar macrophages phagocytize?

Answer 49

toxic particles
allergens
infectious material (bacteria or another pathogen)

Question 50

What is the primary immune defense system of the alveoli?

Answer 50

Alveolar macrophages

Question 51

What does an Alveolar macrophages do once it has phagocytized a particle or pathogen?

Answer 51

Once a macrophage has phagocytized a particle or pathogen, it migrates toward the ciliary surface of the bronchiolar system. Once on the surface, the cilia carry the macrophage and particles to the mouth to be expectorated or swallowed.