Mechanisms of Ventilation

Question 1

Which lung is a mis-swallowed bolus more likely to go into and why

Answer 1

The right lung simply because of how the trachea is shaped

Question 2

Lobes of the lungs

Answer 2

Superior, middle and inferior lobes (no middle in left lung)

Question 3

Label

Answer 3

Question 4

Which is closer to the mouth - trachea or oesophagus

Answer 4

The trachea is closer to the mouth (anterior to the oesophagus)

Question 5

Role of the epiglottis

Answer 5

It is a flap that closes the trachea up and stops food from entering

Question 6

Remember diaphragmatic breathing

Answer 6

you learned this in school, just needed to put this for the sake of it

Question 7

What major organ is right below the diaphragm

Answer 7

Liver

Question 8

Where does the phrenic nerve originate/go through and what does it do

Answer 8

Cervical vertebrae - C3-5

Travels from vertebrae across anterior scalene, then goes through superior thoracic aperture, down into thorax, anterior to root of lung then passes alongisde pericardium where it enters and innervates the diaphragm

Innervates the diaphragm

Question 9

What is the diaphragm attached to (on the thorax)

Answer 9

Anteriorly attaches into xiphoid process and costal margin; laterally attaches to ribs 6-12; posteriorly attached to T12

Question 10

Directions of intercostal muscles

Answer 10

External intercostal muscles are like the forearms and hands in pocket; internal is the opposite

Question 11

When do external intercostal muscles contract

Answer 11

During inspiration

Question 12

Accessory muscles of ventilation

Answer 12

Sternocleidomastoid/sternomastoid, trapezius, scalene muscles, pecs, external intercostals

Question 13

Compare and contrast the directions of movement of the sternum and ribs when lungs expand during inspiration

Answer 13

The sternum is like a handle that pulls anteriorly to expand; the ribs move like a bucket handle

Question 14

Pleurisy

Answer 14

Inflammation of pleura; can be characterised by sharp chest pain, worsened during ventilation

Question 15

Does the cervical pleura cross the superior thoracic aperture?

How might/might not this affect appearance?

Answer 15

It does cross the superior aperture at the point of the cervical parietal pleura, but there is a tough membrane around the lungs that keep it rigid and do not show ventilation

Question 16

How are the pleural layers adherent to one another

Answer 16

Surface tension via surfactant

Think of two thin sheets of glass with a bit of liquid between them; very hard to separate but easily glide

Question 17

How do babies breathe differently to adults

Answer 17

Babies cannot really use accessory muscles during ventilation and the ribs are more horizontal so pump/bucket handle movements are ineffective

Instead they use abdominal breathing, done by contracting the diaphragm

This has high risk of respiratory failure

Question 18

How long are newborns nasal breathers

Answer 18

4-6 weeks

Question 19

Harrisons sulcus

Answer 19

An indentation on the chest roughly along the 6th rib caused by repeated respiratory distress at a young age since the ribs are not fully formed and get easily deformed

Question 20

Costodiaphragmatic and Costomediastinal recesses

Answer 20

Recesses that are normally not filled by anything, but when fluid collects in the lungs, it can be seen at these locations and the fluid must be removed

Question 21

What might use of accessory muscles while at rest be a sign of

Answer 21

This can be a sign of respiratory distress with two main types;

neonatal respiratory distress syndrome which affects newborns

Acute respiratory distress syndrome (ARDS) which can affect people of any age

Question 22

What causes acute respiratory distress syndrome (ARDS)

Answer 22

Fluid/proteins leak from blood vessels into alveoli so lungs become stiff and cannot work normally

Question 23

Carina

Answer 23

Ridge at the base of the trachea (windpipe) that separates the openings of the right and left main bronchi

Question 24

Asthma

Answer 24

Inflammatory disease of airways of lungs

Muscles around airway walls tighten and thus narrower airways; lining of airways inflames

Question 25

Pneumothorax

Answer 25

An opening/hole in parietal pleura; air enters the parietal pleura and lung can collapse

Question 26

Non-tension Pneumothorax

Answer 26

Normal hole with no blockages; air just goes in and out

Question 27

Tension Pneumothorax

Answer 27

Tissue formed at hole forms a valve and closes

When inhaling the flap goes down, but closes during exhalation. Air builds up as it cannot leave

This causes pressure on the heart which deviates to the left and undergoes fibrilation and heart failure

Medical emergency

Question 28

Emphysema

Answer 28

Tissue in lungs becomes very inflammed; especially alveoli which over-inflate. Air easily gets in but cannot leave easily.

Lungs do not change very significantly in size for those affected

Question 29

How does a removed lung look in an x-ray

Answer 29

This is fluid that has collected in the pleural cavity over time ad must be drained periodically