0818 - anatomy of the respiratory system - AHF

Question 1

What constitutes the upper respiratory tract?

Answer 1

nose

nasal cavity

oral cavity

pharynx

Question 2

What constitutes the lower respiratory tract?

Answer 2

larynx

trachea

bronchus

Question 3

Label the external features of the nose.

Answer 3

Question 4

Label the bones and cartilages of the external nose.

Answer 4

Question 5

Name the recesses between the conchae, and what paranasal sinus drains where.

Answer 5

Question 6

What are the 3 major functions of the nose?

Answer 6

• warming, moistening and filtering air (inferior and middle turbinate covered with respiratory epithelia)
• olfactory sensation (superior turbinate covered with olfactory epithelia)
• speech modification (sinuses provide resonance)

Question 7

What is the pharynx?

Answer 7

• muscular tube (“funnel”) extending from base of skull to oesophagus
• nasopharynx, oropharynx, laryngopharynx

Question 8

What, and where is the larynx?

Answer 8

• “voice box”

connects laryngopharynx with trachea

• between C4 - C6
• comprises 9 cartilages
  
  • singles
    
    • thyroid
    • epiglottis
    • cricoid
  • pairs
    
    • arytenoid
    • corniculate
    • cuneiform

Question 9

What are the vestibular and vocal folds?

Answer 9

Vestibular fold: superior pair; “false vocal chord”; mucosa of larynx that folds around the vestibular ligament (thickened free lower margin of quadrangular membrane)

Vocal fold: inferior pair; “true vocal chord”; mucosa of larynx that folds around the vocal ligament (thickened free upper margin of cricothyroid membrane)

Question 10

Label this diagram:

Answer 10

Question 11

What is the position of the vocal folds during forced inspiration? During phonation?

Answer 11

Inspiration: vocal folds abducted, rima glottides open, vestibule open

Phonation: vocal folds adducted, vestibule open

Question 12

What is the shape of the vocal folds when making a low-pitched sound? High-pitched sound?

Answer 12

Low: short, wide

High: long, narrow

Question 13

At what level does the trachea bifurcate?

Answer 13

T4, sternal angle

Question 14

How many U-shaped tracheal cartilages are there? What is between the rings?

Answer 14

14 - 17

Anular ligaments

Question 15

Which bronchus is essentially a continuation of the trachea?

Answer 15

Right; it is more vertical, shorter and wider than the left, so more likely to get foreign objects lodged there.

Question 16

What is the lung root?

Answer 16

All the structures (primary bronchus, pulmonary artery, pulmonary vein, bronchial artery, bronchial vein, lymphatic vessels, lymphatic node, nerve) that pass through the hilum and the pleural sleeve they are wrapped in.

Question 17

Name the fissures and lobes of the left and right lungs.

Answer 17

Fissures:

L - oblique fissure

R - oblique fissure, horizontal fissure

Lobes:

L - superior lobe, inferior lobe

R - superior lobe, middle lobe, inferior lobe

Question 18

Outline the structures within each lung lobule.

Answer 18

• single terminal bronchiole and its branches (i.e. respiratory bronchioles, alveolar ducts, alveolar sacs, alveolar
• associated blood vessels (i.e. arteriole, capillaries, venules) and lymphatic vessels

Question 19

How many segments does each lung have? Describe them.

Answer 19

10 segments (10 segments of bronchi; each 1 supplies a different lung segment)

Segments are

• wedge-shaped
• segmental bronchi and pulmonary arteries are centralised
• intersegmental veins between segments
• separated by connective tissues
• functionally independent, so can remove a segment and still have a functional lung

Question 20

What is the difference between type I and type II alveolar cells?

Answer 20

Type I:

• thin, squamous epithelial cells
• constitute 97% of alveolar surfaces
• provide air-blood barrier for gas exchange

Type II:

• cuboidal epithelial cells
• constitute 3% of alveolar surfaces
• secrete surfactant (thin layer of salt) to lower surface tension and hence ease lung expansion
• also repair and replace type I cells after injury

Question 21

Outline the structures that gas must diffuse through between an alveolus and a capillary.

Answer 21

• epithelial alveolar cells
• basal lamina (basement membrane)
• endothelial cells of capillary

Question 22

Where do the bronchial arteries branch from?

Answer 22

Thoracic aorta

Question 23

Where do the bronchial veins drain to?

Answer 23

Azygos vein (R), hemiazygos vein (L), but they communicate with the pulmonary veins via a shunt.

Question 24

Trace the lymph drainage out of the lung.

Answer 24

Question 25

What does the visceral (pulmonary) pleura do?

Answer 25

Covers the lungs and invaginates into lung fissures; it is continuous with the parietal pleura at the lung root.

Question 26

What are the 4 parts of the parietal pleura?

Answer 26

• costal pleura
• diaphragmatic pleura
• mediastinal pleura
• cervical pleura

Question 27

At what levels do the vena cava, oesophagus and aorta go through the diaphragm?

Answer 27

T8, T10, T12, respectively.

Question 28

Which muscles are used during quiet inspiration? How?

Answer 28

Diaphragm

Thorax lifted and widened, diaphragm contracted (lowered) because thoracic pressure higher than abdominal pressure; air passively flows in.

Question 29

Which muscles are used during quiet expiration? How?

Answer 29

Diaphragm

Thorax lowered and narrowed, diaphragm relaxed (elevated) because abdominal pressure higher than thoracic pressure; air passively flows out.

Question 30

Which muscles are used during forced inspiration? How?

Answer 30

• diaphragm
• scalene
• sternocleidomastoid
• • external intercostal*
• • parasternal intercostal*

Thorax lifted and widened, diaphragm contracted (lowered) because thoracic pressure higher than abdominal pressure; air passively flows in, but also, the accessory muscles pull up to further expand the volume of the thorax so more air inspired.

Question 31

Which muscles are used during forced expiration? How?

Answer 31

• diaphragm
• internal oblique
• external oblique
• rectus abdominus
• transversus abdominus
• • internal intercostal*
• • innermost intercostal*
• • triangularis sterni*

Thorax lowered and narrowed, diaphragm relaxed (elevated) because abdominal pressure higher than thoracic pressure; air passively flows out, but also, the accessory muscles pull down to further reduce the volume of the thorax so more air expired.