Lecture 15: The Lower Respiratory Tract

Question 1

What are the components of the LRT?

5

Answer 1

• Larynx
• Trachea
• Bronchi
• Bronchioles
• Alveoli

Question 2

Where does the LRT want to conduct air form/to?

Answer 2

The site of gas exchange

Question 3

What does the lower respiratory tract do to inspired air?

Answer 3

Completes cleaning, warming and humidifying of air

Question 4

What does the LRT provide in terms of a site for gas exchange?
(2)

Answer 4

• Provides a barrier between the air and blood

- Large surface area for gas exchange

Question 5

The larynx is a passage for what?

Answer 5

Air only

Question 6

Where is the larynx?

Answer 6

Anterior to the oesophagus from the hyoid bone to trachea

Question 7

What cartilage protects and maintains an open airway?

Answer 7

• Cricoid cartilage

- Tracheal cartilage

Question 8

What does the Epiglottis do?

Answer 8

Closes over the airway when swallowing

Question 9

What is the Glottis?

Answer 9

Voicebox

Question 10

What happens at the vocal folds/cords?

Answer 10

Passing air causes vibrations therefore sound waves

Question 11

What are the vocal folds/cords used for?

Answer 11

Normal phonation

Question 12

What does testosterone do to the vocal cords?

Answer 12

Affects cartilage and muscle resulting in longer and thicker folds therefore a deeper voice

Question 13

What are the vocal folds/vocal cords also known as?

Answer 13

True vocal cords

Question 14

What are the Vestibular folds also know as?

Answer 14

False vocal cords

Question 15

Where are the vestibular folds?

Answer 15

Superior to the vocal folds

Question 16

What is the role of the Vestibular fold?

Answer 16

Prevent foreign objects entering into the glottis

Question 17

What can the Vestibular fold produce?

Answer 17

Very deep sounds

Question 18

Where is the Trachea?

Answer 18

Anterior to the oesophagus between the larynx and the bronchi

Question 19

What is the function of the trachea?

Answer 19

Maintain a patent airway

Question 20

What is the trachea made of?

Answer 20

c-shaped cartilage rings where the ends are connected by a band of smooth muscle

Question 21

What is the name of the smooth muscle that connects the C-shaped cartilage of the trachea?

Answer 21

Trachealis

Question 22

What causes coughing?

Answer 22

Contracting of trachealis

Question 23

What is the lamina propia/submucosa layers of the trachea made of?

Answer 23

Many elastin fibres

Question 24

What is the trachea lined with?

Answer 24

Respiratory epithelium

Question 25

What happens to debris in the trachea?

Answer 25

It is removed by the Mucociliary escalator to the pharynx, to be swallowed and digested

Question 26

How does the mucociliary escalator work?

Answer 26

Mucus from goblet cells and mucous glands trap debris and cilia move it to the pharynx

Question 27

How many lobes are in the right lung?

Answer 27

3 lobes

Question 28

How many lobes are in the left lung?

Answer 28

2 lobes

Question 29

What is the hilum?

Answer 29

Where bronchi & blood vessels enter the lungs

Question 30

Where is the apex of the lung?

Answer 30

The superior region of the lungs

Question 31

Where is the base of the lung?

Answer 31

The inferior region of the lungs

Question 32

What is at the start of the bronchial tree?

Answer 32

The trachea

Question 33

What branches off the trachea in the bronchial tree?

Answer 33

Primary bronchi

Question 34

What branches off the primary bronchi in the bronchial tree?

Answer 34

Secondary (lobar) bronchi

Question 35

What branches off the secondary (lobar) bronchi in the bronchial tree?

Answer 35

Tertiary (segmental) bronchi

Question 36

What branches off the tertiary bronchi in the bronchial tree?

Answer 36

Bronchioles

Question 37

What branches off the Bronchioles in the bronchial tree?

Answer 37

Terminal bronchioles

Question 38

What is the Trachea lined with and made from? | 2

Answer 38

- Respiratory epithelium | - C-shaped cartilage rings

Question 39

What is the primary bronchi lined with and made from?

Answer 39

Lined with respiratory epithelium and made from cartilage and complete smooth muscle rings

Question 40

What is the secondary and tertiary bronchi lined with and made from?

Answer 40

Lined with respiratory epithelium made from cartilage plates

Question 41

What happens to the respiratory epithelium in the secondary and tertiary bronchi?

Answer 41

Starts to decrease in height and goblet cell numbers reduce

Question 42

What are the Bronchioles lined with and made from?

Answer 42

Lined with cuboidal epithelium and made from thick smooth muscle

Question 43

What causes bronchoconstriction/dilation?

Answer 43

Smooth muscle in the bronchioles

Question 44

What do terminal bronchioles supply?

Answer 44

Each pulmonary lobule

Question 45

What are Pulmonary lobules made of?

Answer 45

Many alveoli (air sacs) arranged like bunches of grapes

Question 46

Roughly how many Alveoli are there per lung?

Answer 46

150 million

Question 47

What do the Alveoli provide to the respiratory zone?

Answer 47

Most of the lung volume and an enormous surface area

Question 48

Alveolar walls are very thin and made of what?

Answer 48

Simple squamous epithelium on a thin basement membrane

Question 49

What are the external surfaces of alveoli covered with?

Answer 49

A fine network of pulmonary capillaries

Question 50

What are Pneumocytes?

Answer 50

Lung epithelial cells

Question 51

What kind of cells are type 1 Pneumocytes?

Answer 51

Squamous

Question 52

What kind of cells are type 2 Pneumocytes?

Answer 52

Cuboidal

Question 53

What do type 1 pneumocytes form?

Answer 53

The respiratory membrane/blood-air barrier with capillary wall and shared basement membrane

Question 54

Where are type 2 pneumocytes?

Answer 54

Scattered amongst type 1 pneumocytes

Question 55

What do type 2 pneumocytes secrete?

Answer 55

Surfactant, a complex lipoprotein

Question 56

What does Lipoprotein do?

Answer 56

Reduces the surface tension of alveolar fluid

Question 57

What do roaming macrophage do?

Answer 57

Remove debris that makes it to alveoli

Question 58

What 3 parts make the blood air barrier?

Answer 58

- Alveolar cell layer - Fused basement membrane of alveolar epithelium and capillary endothelium - Capillary endothelium