Lower Respiratory System

Question 1

Where does the trachea end?

Answer 1

The carina

Question 2

At what thoracic level is the carina?

Answer 2

Roughly the 5th thoracic vertebrae.

Question 3

Why is it more likely that you will enter the right lung accidentally?

Answer 3

The right lung branches off at about 25 degree angle, and it is wider and more vertical than the left.

Question 4

What are the major bronchial divisions of both lungs?

Answer 4

There is left upper and lower, and right upper, middle, and lower.

Question 5

What is peribronchial connective tissue?

Answer 5

A sheath that surrounds the subsegmental bronchi containing pulmonary vessels, bronchial arteries, lymphatic vessels, nerves, and of course the bronchus itself.

Question 6

Where does the bronchial tree stop having cartilage on it?

Answer 6

At the subsegmental bronchi

Question 7

At which generation of the bronchial tree does the airway change from conductive to respiratory?

Answer 7

From generation 17 (respiratory bronchioles) to the last generation, 25 (the alveolar sacs).

Question 8

What are the three layers of airway tissues?

Answer 8

Cartilage (outermost), lamina propria, and epithelium (innermost).

Question 9

What kind of tissue makes up the epithelium of the airway?

Answer 9

Pseudostratified ciliated columnar epithelium from trachea to respiratory bronchioles.

Question 10

What is the purpose of the basal membrane of the airway?

Answer 10

It separates the epithelial cells from the lamina propria and is made of basal cells

Question 11

Where in the airway do we find mast cells and what are they?

Answer 11

They are found in the lamina propria and are immune cells often responsible for anaphylaxis and asthma inflammation.

Question 12

What controls the tone of the smooth muscle of the airway and how?

Answer 12

The autonomic nervous system controls the smooth muscle. The sympathetic dilates and the parasympathetic contracts.

Question 13

What is the functional unit of the lungs?

Answer 13

The alveoli

Question 14

Where does the flow of inspired gas stop?

Answer 14

The terminal bronchioles

Question 15

What is Brownian movement?

Answer 15

The natural molecular flow of gas that is the dominant mechanism of gas movement in the terminal bronchioles (alveoli).

Question 16

What kind of cells are found in the alveoli?

Answer 16

Type I (squamous pneumocytes) which are responsible for gas exchange and Type II (granular pneumocytes) which are responsible for the production of surfactant

Question 17

What does surfactant do?

Answer 17

It reduces the surface tension of the fluid lining the alveoli to facilitate the movement of gas through the membrane.

Question 18

What are type III pneumocytes?

Answer 18

They are macrophages that remove bacteria and other wastes from the primary lobule

Question 19

Where do type III pneumocytes originate?

Answer 19

They originate from stem cells in the bone marrow.

Question 20

What is tight space and loose space in the lungs?

Answer 20

Tight space is space between alveolar epithelium and endothelium of pulmonary capillaries and loose space surrounds the acini (around alveoli and capillaries).

Question 21

What are the Channels of Martin?

Answer 21

Channels between bronchioles for communication.

Question 22

What are Canals of Lambert?

Answer 22

Small channels between alveoli and terminal bronchioles.

Question 23

What are pores of Kohn?

Answer 23

Channels between alveoli for communication that are formed because of disease, age, or macrophages (infection).

Question 24

What are Clara cells?

Answer 24

A type of cell found in the primary lobule that protect the bronchiolar epithelium and may contain enzymes that detoxify inhaled substances.