Lungs and Intralobular Airways

Question 1

What is the general structure of the lung?

Answer 1

Cone shaped
Apex
3 surfaces
3 borders

Question 2

What are the borders of the lungs?

Answer 2

Diaphragmatic - concave surface that is directed inferiorly, it forms the base of the lung
Costal - smooth, convex surface which may possess impressions made by the ribs
Mediastinal - irregular surface where the hilum of the lung is located

Question 3

Which lung is the shortest and widest?

Answer 3

Right

Question 4

What causes the impressions seen on the right lung?

Answer 4

Braciocephalic vein
Arch of azygos
Oesophagus
Superior vena cava

Question 5

What causes the impressions seen on the left lung?

Answer 5

Arch of aorta
Subclavian artery
Descending aorta
Heart

Question 5

Does parasympathetic innervation dilate or constrict the bronchioles?

Answer 5

Constrict

Question 6

Does sympathetic innervation dilate or constrict the bronchioles?

Answer 6

Dilate

Question 7

What do the bronchial vessels supply?

Answer 7

Structures at the root of the lung, supporting tissues of the lungs and visceral pleura

Question 8

What do the parasympathetic fibres supply?

Answer 8

Smooth muscle and mucous glands

Question 9

Where do the bronchial vessels arise?

Answer 9

Thoracic aorta

Question 9

Where do the bronchial veins empty?

Answer 9

The left bronchial vein drains into the accessory hemiazygos vein or left superior intercostal vein, while the right bronchial vein drains into the azygos vein.

Question 10

What is ausculated at these places:
2nd costal cartilage
4th costal cartilage
6th costal cartilage
8th rib
10th rib

Answer 10

2nd costal cartilage the anterior borders of the lungs meet in midline

4th costal cartilage the anterior border of the left lung moves away from midline

6th costal cartilage the anterior border of the right lung moves away from midline and the lower borders of both lungs cross the midclavicular line

8th rib the lower borders of both lungs cross the midaxillary line

10th rib the lower border of the posterior aspect of both lungs are level with the rib

Question 11

Where do you find the upper lobe of the lungs?

Answer 11

Left lung - Left posterior thorax at the level of T2

Right lung - Right posterior thorax between the seventh and tenth ribs

Question 12

Where do you find the middle lobe of the right lung?

Answer 12

Right midclavicular line between fourth and sixth rib

Question 13

Where do you find the lower lobe of the right lung?

Answer 13

Right posterior thorax between the seventh and tenth ribs

Question 14

Where do you find the apex of the left lung?

Answer 14

Above the left clavicle

Question 15

Where do the primary bronchi enter the lung at?

Answer 15

The hilum

Question 16

What do the primary bronchi give rise to?

Answer 16

Series of branching, interlobular airways.

Question 17

What is the order of airflow leaving the primary bronchi en route to the alveoli?

Answer 17

Secondary bronchi
Tertiary bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli

Question 18

How many secondary bronchi does the right bronchi and left bronchi give rise to?

Answer 18

Right = 3
Left = 2

Question 19

What do these bronchi contain?
Primary
Secondary
Tertiary

Answer 19

P = Contains C-shaped rings of cartilage
S = Contains larges plates of cartilage connected by fibrocollagenous bands
T = Small cartilaginous plates interspersed with fibrocollagenous bands

Question 20

What does each of these bronchi have?
Primary
Secondary
Tertiary

Answer 20

P = Some smooth muscles present in lamina propria

S = Presents a band of smooth muscle between mucosa and submucosal layers

T = Elastic fibres in lamina propria and an abundance of muscle fibres

Question 21

What do the secondary bronchi divide to form?

Answer 21

Tertiary bronchi

Question 22

What do these bronchi supply?
Primary
Secondary
Tertiary

Answer 22

P = Supply a whole lung
S = Supply individual lung lobes T = Supply individual bronchopulmonary segments

Question 23

What are the bronchi also known as? Primary Secondary Tertiary

Answer 23

P = extra pulmonary bronchi S = Lobar bronchi T = Segmental bronchi

Question 24

What happens to the bronchi as it continues to subdivide?

Answer 24

Get smaller and smaller in diameter. As they get smaller the cartilage gets sparser and is mainly located at sites of bifurcation. In contrast, the amount of smooth muscle increases.

Question 25

What epithelium is found throughout the bronchi?

Answer 25

Ciliated columnar epithelium

Question 26

What form does the epithelium start as in the primary bronchi then progress to?

Answer 26

Pseudostrified epithelium then simple ciliated columnar

Question 27

What other cell types are located in the epithelium?

Answer 27

Ciliated Cells- Waft mucous-trapped particles towards the oropharynx Basal Cells- Stem cells which may develop into any of the other cell types Intermediate Cells- Thought to be stem cells that will develop into either ciliated cells or goblet cells Goblet Cells- Produce mucous which traps small particles Neuroendocrine Cells- Secrete bombesin and serotonin

Question 28

What do the walls of the bronchi contain?

Answer 28

Mucosa-associated lymphoid tissue (MALT) and submucosal bronchial glands

Question 29

What gives rise to bronchioles?

Answer 29

The most distal bronchi

Question 30

What are the properties of the bronchioles?

Answer 30

Less than 5 µm in diameter, they do not contain cartilage but their walls are supported by smooth muscle. Continue to divide getting smaller and smaller

Question 31

What are bronchioles lined with?

Answer 31

Simple ciliated epithelium which is initially columnar in shape but become flatter and more cuboidal as the airways decrease in diameter

Question 32

What happens to the number of goblet and neuroendocrine cells with the progression down the bronchial tree?

Answer 32

Decreases

Question 33

The bronchioles possess an additional cell type which produces a surfactant-like material. What is the name of these cells?

Answer 33

Clara cells

Question 34

What does the final bifurcation of the bronchioles gives rise to?

Answer 34

Terminal bronchioles - the final airways of conducting zone

Question 35

What do the terminal bronchioles do?

Answer 35

Lead into the respiratory bronchioles, the first airways of the respiratory zone

Question 36

What lines the airways of respiratory zones?

Answer 36

Cuboidal epithelium

Question 37

What do the respiratory bronchioles lead into?

Answer 37

Alveolar ducts

Question 38

What are the walls of the alveolar ducts lined with?

Answer 38

Openings of the alveoli

Question 39

What do the ends of each alveolar duct give rise to?

Answer 39

2 or 3 alveolar sacs, which are clusters of alveolar that share a common opening

Question 40

What do alveoli project from?

Answer 40

Respiratory bronchioles, alveolar ducts and alveolar sacs

Question 41

What do the alveoli form?

Answer 41

Small pockets which are opened on one side and form the site for gas exchange between the air and the blood

Question 42

How is air separated?

Answer 42

Alveolar cell Fused basement membrane of the alveolar cell and the capillary cell Endothelial cell of capillary

Question 43

What type of epithelium forms the wall of the alveolus?

Answer 43

Simple squamous

Question 44

What cell types are found at the alveoli?

Answer 44

Type I cells, type II cells and macrophages/dust cells.

Question 45

What are type 1 cells?

Answer 45

Squamous cell, which forms the wall of the alveolus and is the site of gas exchange

Question 46

What are type 2 cells?

Answer 46

Round cell, which may bulge into the alveolus, secretes surfactant