lecture 15 - lower respiratory tract

Question 1

What are the components of the lower respiratory tract (5)?

Answer 1

Larynx, trachea, bronchi, bronchioles, alveoli

Question 2

What are the 3 key functions of the lower respiratory tract?

Answer 2

Conducts air to/from the site of gas exchange, completes cleaning, warming and humidifying of air, provides a barrier between air and blood with a large surface area for gas exchange

Question 3

What travels through the larynx?

Answer 3

Air - no food

Question 4

Where does the larynx sit in relation to the oesophagus?

Answer 4

Anteriorly

Question 5

Where are the boundaries of the larynx?

Answer 5

From hyoid bone to the top of the trachea

Question 6

What is the key function of the cartilages of the larynx?

Answer 6

To protect/maintain and open/patent airway

Question 7

What structure closes over the airway when swallowing to prevent food entering the LRT?

Answer 7

The epiglottis

Question 8

What is the common name for the glottis?

Answer 8

Voicebox

Question 9

What are the 2 types of folds found in the larynx?

Answer 9

Vocal folds and vestibular folds

Question 10

What folds are the ‘true’ vocal cords?

Answer 10

Vocal folds

Question 11

What folds are the ‘false’ vocal folds?

Answer 11

Vestibular folds

Question 12

What determines the opening and closing of the glottis?

Answer 12

The vocal cords, which are attached to cartilage

Question 13

What causes the vocal folds to produce sound?

Answer 13

Air passing over them causes vibrations and sound waves

Question 14

Why do men have deeper voices?

Answer 14

Testosterone affects cartilage and muscle of the glottis, resulting in longer, thicker vocal folds that produce deeper sounds

Question 15

Where do the vestibular folds sit in relation to the vocal folds?

Answer 15

They sit superiorly

Question 16

What is the main function of the vestibular folds?

Answer 16

Prevent foreign object (e.g. food) from entering the glottis

Question 17

What type of sounds can (rarely) be produced by the vestibular folds?

Answer 17

Very deep sounds

Question 18

Where is the trachea located?

Answer 18

Anterior to the oesophagus, between the larynx and primary bronchi

Question 19

What are the 2 main functions of the trachea?

Answer 19

Maintain a patent airway and clean, warm and humidify air

Question 20

How does the trachea maintain a patent airway?

Answer 20

Has C-shaped cartilage rings that keep it open, ends connected to by band of smooth muscle (trachealis), lamina propria and sub-mucosa contains many elastin fibres

Question 21

What lines the trachea?

Answer 21

Respiratory epithelia

Question 22

Where is the musociliary escalator found?

Answer 22

In the trachea

Question 23

What is the function of the musociliary escalator?

Answer 23

Removes debris to the pharynx to be swallowed and digested.

Question 24

What generates the mucus for the musociliary escalator?

Answer 24

Goblet cells and mucous glands.

Question 25

How many lobes does the right lung have?

Answer 25

3

Question 26

How many lobes does the left lung have?

Answer 26

2

Question 27

What is the shape of the base of the lungs, and why?

Answer 27

Dome shaped that sits of the diaphragm

Question 28

Where do the bronchi and blood vessels enter the lungs?

Answer 28

The hilum

Question 29

Where do the apexes of the lungs sit?

Answer 29

Below the clavicle

Question 30

What is the name for the lateral surface of the lungs?

Answer 30

The costal surface

Question 31

Where does the base of the lungs sit?

Answer 31

On the diaphragm

Question 32

What are the components, from top to bottom, of the bronchial tree?

Answer 32

Trachea, primary bronchi,l secondary bronchi, tertiary bronchi, bronchioles, terminal bronchioles

Question 33

Where are the trachealis muscles found on the trachea?

Answer 33

At the posterior of the trachea, connecting the C shaped cartilage rings

Question 34

Are the cartilage rings surrounding the trachea C-shaped or complete?

Answer 34

C-shaped

Question 35

Are the cartilage rings surrounding the primary bronchi C-shaped or complete?

Answer 35

complete

Question 36

What is the cartilage structure found in the secondary and tertiary bronchi?

Answer 36

Cartilage plates

Question 37

How does the epithelium change in the secondary and tertiary bronchi?

Answer 37

Respiratory epithelium decreases in height and concentration of goblet cells decreases.

Question 38

What is the diameter of bronchioles?

Answer 38

<1mm

Question 39

What is the epithelium of the bronchioles, and why?

Answer 39

Cuboidal - no space for columnar cells

Question 40

What is the structure of the bronchioles?

Answer 40

No cartilage, but thick smooth muscle for bronchoconstriction and dilation. Cuboidal epithelium

Question 41

What is the diameter of a terminal bronchiole?

Answer 41

<0.5mm

Question 42

What does each terminal bronchiole supply?

Answer 42

A pulmonary lobule

Question 43

What is the structure of a pulmonary lobule?

Answer 43

Made of many alveoli arranged like a ‘bunch of grapes’

Question 44

What is the structure of an alveolus?

Answer 44

Very thinned wall, covered in a fine network of pulmonary capillaries, open on one side

Question 45

What is the epithelium of an alveolus?

Answer 45

Simple squamous epithelium on a thin basement membrane

Question 46

What cells make up alveoli?

Answer 46

Pneumocytes

Question 47

What are pneumocytes?

Answer 47

Lung epithelial cells that make up the alveoli

Question 48

What are the 2 types of pneumocytes?

Answer 48

Type I (squamous), type II (cuboidal)

Question 49

What is the function of type I pneumocytes?

Answer 49

Forms the respiratory membrane/blood air barrier with capillary wall and shared basement membrane

Question 50

What is the function of the type II pneumocytes?

Answer 50

Scattered amongst type I. Secrete surfactant, a complex lipoprotein (phospholipid) that reduces the surface tension of alveolar fluid

Question 51

What is secreted by type II pneumocytes?

Answer 51

Surfactant

Question 52

What is surfactant?

Answer 52

A complex lipoprotein (phospholipid) that reduces the surface tension of alveolar fluid

Question 53

What removes the debris that makes its way into the alveoli?

Answer 53

Roaming macrophages

Question 54

What type of epithelial cell type are type I pneumocytes?

Answer 54

Squamous

Question 55

What type of cell make up type II pneumocytes?

Answer 55

cuboidal

Question 56

What is the alternative name for the respiratory membrane?

Answer 56

Blood-air barrier

Question 57

What is the structure of the blood-air barrier/respiratory membrane?

Answer 57

Layer of alveolar epithelium and capillary endothelial cells, with the alveolar and capillary basement membranes fused together between them

Question 58

What sits between the alveolar epithelium and capillary endothelium in the respiratory membrane?

Answer 58

Alveolar and capillary basement membranes fused together