Histology of the Respiratory System

Question 1

What two process does respiration involve?

Answer 1

Physical and chemical

Question 2

What does the physical process of respiration entail?

Answer 2

Ventilation involves inspiratory and expiratory movements of the chest.

Question 3

What does the chemical process of respiration involve?

Answer 3

The exchange of gases between air and blood takes place at the cellular level

Question 4

What does parasympathetic innervation do in the lungs?

Answer 4

Bronchioconstriction, mucous secretion and vasodilatation

Question 5

What does the sympathetic innervation do in the lungs?

Answer 5

Bronchodilatation

Question 6

What is the total distance for gas to be exchanged?

Answer 6

0.2 micro meters

Question 7

What happens during breathlessness?

Answer 7

There is fluid in the gap between the alveol and the capillary and so the distance is increased and so the gas can’t diffuse properly.

Question 8

What are the four main layers of the respiratory system?

Answer 8

Mucosa
Submucosa
Cartilage and supporting muscle
Adventitia

Question 9

What consists of the mucosa?

Answer 9

There is a epithelium and a connective tissue layer which consists of connective tissue which is known as the lamina propria.

Question 10

What does the sub mucosal layer have?

Answer 10

Seromucous glands

Question 11

What do the seromucous glands have?

Answer 11

They have a duct that opens up into the lumin of the mucosa and it release mucous and serous fluids.

Question 12

What is the adventitia?

Answer 12

It s the fibrous connective tissue which covers the tracheal bronchial treee.

Question 13

What kind of cartilage makes up the rings of the trachea?

Answer 13

Hyaline

Question 14

What are the gaps between the cartilage ring filled up with?

Answer 14

They are filled with trachealis muscle and fibroelastic tissue

Question 15

What is the function of the respiratory mucosa and submucosal layer?

Answer 15

It warms and moistens the air and traps any foreign particle in the mucous

Question 16

What cells are present in the mucosal layer?

Answer 16

Goblet cells

Question 17

What cells can differentiate and act as stem cells?

Answer 17

Basal cells

Question 18

What kind of cells are found in the trachea?

Answer 18

Pseudostratified ciliated columnar cells

Question 19

What does the lamina propria contain?

Answer 19

It contains areolar connective tissue which has elastine and also blood vessels. (there might also be some macrophages and immune cells.)

Question 20

Where do the pseudostratified ciliated cells start and where do they end?

Answer 20

It starts at the nose and finishes at the level of the terminal bronchiole

Question 21

What type of cells starts from the terminal bronchiole?

Answer 21

Non-ciliated columnar single layer cells.

Question 22

What kind of tissue makes up the lamina propria?

Answer 22

Loose connective tissue

Question 23

What is in between the submucosal layers?

Answer 23

Elastic fibres

Question 24

What is found in the perichondrium?

Answer 24

Cartilage

Question 25

What is the function of the adventitia?

Answer 25

It connects and supports the trachea to the surrounding tissue. It also contains nerves, vessels and adipose tissue.

Question 26

What two groups can we divide the bronchi into?

Answer 26

Intrapulmonary bronchi and extrapulmonary bronchi

Question 27

What is the histology of the extrapulmonary bronchi?

Answer 27

They represent the histology of the trachea.

Question 28

What is the histology of the intrapulmonary bronchi?

Answer 28

They have less cartilage and it does not completely encircle the lumen and there are layers of smooth muscle between the mucosa and sub-mucosa.

Question 29

What is the diameter of a bronchiole?

Answer 29

less than 1mm

Question 30

What are bronchioles covered in?-

Answer 30

Ciliated columnar epithelium (however in the smaller bronchioles it is non-ciliated)

Question 31

What is different about the histology of bronchioles?

Answer 31

Smooth muscle increases, Clara cells are present which secrete surfactant, no goblet cells, no ciliated cells, no submucosal glands, no cartilage,

Question 32

What type of cells make up the respiratory bronchioles?

Answer 32

Ciliated cuboidal epithelium

Question 33

What are alveolar ducts surrounded by?

Answer 33

Collagen, elastin and smooth muscle

Question 34

What surrounds the alveoli and the alveolar sacs?

Answer 34

by blood vessels and pulmonary capillaries

Question 35

What surrounds the alveoli and the alveolar sacs?

Answer 35

by blood vessels and pulmonary capillaries

Question 36

What type of epithelium makes up the bronchioles?

Answer 36

Simple epithelium wth few cilia

Question 37

How many glands are in the lamina propria in the bronchioles?

Answer 37

None

Question 38

How does the smooth layer in the broncholes compare to that of the bronchi?

Answer 38

It is thicker.

Question 39

Describe the alveolar-capillary interface.

Answer 39

Gaseous exchange takes place through the endothelial cell of the capillary, basement membrane and type I pneumocyte
The walls of the capillary endothelial cell is fused to that of the alveolar cell, there is only a very thin basement membrane between these two cells.

Question 40

What is correct about the club cells (Clara cells)?

Answer 40

Protect airways, regenerate bronchiolar epithelium, produce surfactant.