Lecture 15: LOWER RESPIRATORY TRACT

Question 1

What are the components of the LRT?

Answer 1

Larynx, trachea, bronchi, bronchioles and alveoli

Question 2

What are the functions of the LRT?

Answer 2

Conduct, complete and provide

Question 3

What does the LRT conduct?

Answer 3

Air to/from site of gas exchange

Question 4

What does the LRT complete?

Answer 4

Cleaning, warming and humidifying of air

Question 5

What does the LRT provide?

Answer 5

A barrier between the air and blood, and a large surface area for gas exchange

Question 6

What is the larynx a passage for?

Answer 6

Air only so has respiratory epithelium

Question 7

Where is the larynx positioned?

Answer 7

Anterior to the esophagus

Question 8

Where does the larynx go from?

Answer 8

The hyoid bone to the trachea

Question 9

What does cartilage in the larynx do?

Answer 9

Protect and maintain open airway (remains potent)

Question 10

What does the epiglottis do?

Answer 10

Closes over the airway when swallowing to prevent food entering the larynx

Question 11

What are the cartilage in the larynx?

Answer 11

Cricoid cartilage, thyroid cartilage (with laryngeal prominence) and epiglottis

Question 12

What does glottis mean?

Answer 12

Voicebox

Question 13

What do the folds attach to?

Answer 13

Cartilages

Question 14

What are the folds?

Answer 14

Vocal folds and vestibular folds

Question 15

What are the true vocal cords?

Answer 15

Vocal folds

Question 16

What does air passing the vocal folds do?

Answer 16

Cause vibrations = sound waves

Question 17

What are the vocal folds used for?

Answer 17

Normal phonation

Question 18

What affects cartilage and muscle?

Answer 18

Testosterone, resulting in longer, thicker folds which means a deeper voice

Question 19

What are the false vocal cords?

Answer 19

Vestibular folds

Question 20

Where are the vestibular folds found?

Answer 20

Superior to the vocal folds

Question 21

What do vestibular folds do?

Answer 21

Prevent foreign object entry to glottis if it gets past the epiglottis

Question 22

What sound can the vestibular folds produce?

Answer 22

Very deep sounds

Question 23

Where is the trachea found?

Answer 23

Anterior to the esophagus

Question 24

Where is the trachea between?

Answer 24

The larynx and primary bronchi

Question 25

What is the function of the trachea?

Answer 25

To maintain a potent airway. Clean, warm and humidify air.

Question 26

What epithelium does the trachea have?

Answer 26

Respiratory

Question 27

What is the cartilage in the trachea?

Answer 27

C shaped cartilage rings. They aren't completes so that oesophagus space isn taken up and muscle can run down the posterior

Question 28

What are the ends of the cartilage in the trachea connected by?

Answer 28

A band of smooth muscle (trachealis) which contracts for coughing

Question 29

What is in the lamina propria and submucosa layer of the trachea?

Answer 29

Many elastin fibres and all submucosal glands for producing extra mucus

Question 30

What does the mucocillary escalator do?

Answer 30

Removes debris against gravity to the pharynx to be swallowed and digested

Question 31

What coats the epithelium in the trachea?

Answer 31

Mucus from goblet cells and mucous glands

Question 32

What happens with debris in the trachea?

Answer 32

It becomes trapped

Question 33

What do cilia do in the trachea?

Answer 33

Moves mucus up to the pharynx

Question 34

How many lungs are there?

Answer 34

2

Question 35

How many lung lobes are there?

Answer 35

5

Question 36

How many lobes are there in the right lung?

Answer 36

3 (superior, middle and inferior)

Question 37

How many lobes are there in the left lung?

Answer 37

2 (as the heart takes up more space on the left)

Question 38

What is the hilum?

Answer 38

Where bronchi and blood vessels enter

Question 39

What is the apex of the lungs?

Answer 39

The superior region

Question 40

What is the costal surface of the lungs?

Answer 40

The outer surface against the ribs

Question 41

What is the base of the lungs?

Answer 41

The inferior region which sits on the diaphragm

Question 42

What is the start of the bronchial tree?

Answer 42

Trachea

Question 43

What comes after the trachea?

Answer 43

2 primary bronchi which enter the lungs at the hilum

Question 44

What comes after the primary bronchi?

Answer 44

Secondary (lobar) bronchi - 3 on right and 2 on left

Question 45

What comes after secondary (lobar) bronchi?

Answer 45

Tertiary segmental bronchi

Question 46

what comes after tertiary segmental bronchi?

Answer 46

Bronchioles

Question 47

What comes after the bronchioles?

Answer 47

A lot more branching leads to the terminal bronchioles

Question 48

What is the epithelium of primary bronchi?

Answer 48

Respiratory

Question 49

How is the cartilage and smooth muscle of primary bronchi?

Answer 49

Complete rings as there is no esophagus

Question 50

What is the epithelium of the secondary and tertiary bronchi?

Answer 50

Respiratory epithelium which is starting to decrease in height and less goblet cells

Question 51

How is the cartilage in secondary and tertiary bronchi?

Answer 51

Cartilage plates (not full rings as the air pressure holds them open)

Question 52

What is the size of bronchioles?

Answer 52

Less than 1mm

Question 53

what is the epithelium of the bronchioles?

Answer 53

Cuboidal

Question 54

How is the cartilage and smooth muscle in bronchioles?

Answer 54

No cartilage but thick smooth muscle for bronchoconstriction/dilation

Question 55

What is the size of terminal bronchioles?

Answer 55

Less than 0.5mm

Question 56

What does each terminal bronchiole supply?

Answer 56

A pulmonary lobule

Question 57

What is the respiratory zone made up of?

Answer 57

Pulmonary lobules made of many alveoli (air sacs)

Question 58

How are the alveoli arranged in the pulmonary lobules?

Answer 58

Like bunches of grapes

Question 59

How many alveoli per lung?

Answer 59

Approximately 150 million

Question 60

What makes up most of the lung volume?

Answer 60

Alveoli

Question 61

What does having many alveoli do?

Answer 61

Give an enormous surface area for gas exchange

Question 62

How are the alveolar walls?

Answer 62

Very thin - simple squamous epithelium on a thin basement membrane

Question 63

What is the external surface of alveoli covered in?

Answer 63

A fine network of pulmonary capillaries

Question 64

How is an alveolus described?

Answer 64

Pocket-like (open at one side)

Question 65

What is an alveolus covered by?

Answer 65

A dense capillary network

Question 66

What are the cells of the alveolus?

Answer 66

Pneumocytes (lung epithelial cells)

Question 67

What are the types of pneumocytes?

Answer 67

Type 1 squamous and Type 2 cuboidal

Question 68

What does the type 1 squamous cells form?

Answer 68

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

Question 69

Where are type 2 cuboidal cells found?

Answer 69

Scattered amongst type 1

Question 70

What do type 2 cuboidal cells do?

Answer 70

Secrete surfactant, a complex lipoprotein (phospholipid) that reduces the surface tension. of alveolar fluid (no deformation)

Question 71

What do roaming macrophages in the alveoli do?

Answer 71

Remove any debris which makes it to the alveoli

Question 72

What does each alveolus connect to?

Answer 72

Neighbouring alveoli so that air can flow through

Question 73

What is the respiratory membrane made of?

Answer 73

The alveolar cell layer, fused basement membrane of alveolar and capillary endothelium and also the capillary endothelium

Question 74

What way does oxygen flow from?

Answer 74

Alveoli to capillaries

Question 75

What way does carbon dioxide flow?

Answer 75

From capillaries to alveoli

Question 76

What is the respiratory membrane the site of?

Answer 76

Gas exchange