Bronchi, Lungs, Pleura and Diaphragm

Question 1

What forms the bronchial tree?

Answer 1

Trachea, Primary bronchi, Lobar bronchi, Segmental bronchi

Question 2

Where does the trachea extend from and to where?

Answer 2

From C6 to T4/5 and lowest ring of cartilage has a hook - CARINA

Question 3

Where are the primary bronchi formed?

Answer 3

T4/5 with the RHS wider and more vertical than LHS

Question 4

Where are the Lobar bronchi formed?

Answer 4

In the lungs and supply the lungs

Question 5

Where do the Segmental bronchi supply?

Answer 5

The bronchopulmonary segments (self-contained independent units of lung tissue)

Question 6

Where is the neck cut if immediate access to the trachea is needed?

Answer 6

Between the thyroid cartilage and cricoid cartilage

Question 7

How many bronchopulmonary segments are there?

Answer 7

10 in each lung - smallest, functionally independent region: own neurovascular supply

Question 8

Where are the lungs located?

Answer 8

In the thorax, separated by mediastinum

Question 9

In what do the lungs lie?

Answer 9

Each free in its pleural cavity - apart from attachment to heart via pulmonary vessels and trachea at the hilum

Question 10

What is the structure of the lungs?

Answer 10

Apex - rises 3/4cm above 1st costal cartilage

Base - concave, rests on convex diaphragm surface

Question 11

What are the borders and surfaces of the lungs?

Answer 11

3 borders: Ant, post, inf.

3 surfaces: Costal, Mediastinal, Diaphragmatic

Question 12

What does the diaphragm separates the lungs from?

Answer 12

RL from right lobe of liver

LL from left lobe of liver, stomach and spleen

Question 13

What are the general features of the mediastinal surface of the lung?

Answer 13

Posterior in contact with thoracic vertebrae, anterior - concave to accommodate heart, with larger cardiac impression on LL than RL
Above and behind cardiac impression - hilum of lung

Question 14

What is the structure of the left lung?

Answer 14

2 lobes - sup and inf - separated by oblique fissure

Question 15

What vessel grooves can be seen on the apical surface of the left lung?

Answer 15

For aorta, left subclavian, braciocephalic vein

Question 16

What are some important features on the left lung?

Answer 16

Oblique fissure, cardiac notch, pulmonary ligament

Question 17

What is the structure of the right lung?

Answer 17

3 lobes: Sup, middle, inf
Sup separated by horizontal fissure, Inf by oblique fissure
Slightly larger than LL

Question 18

What vessel grooves can be seen on the right lung?

Answer 18

Right subclavian artery, Sup vena cava, azygous vein, inf vena cava, oesophagus

Question 19

What are some important structures on right lung?

Answer 19

Cardiac impression, Oblique fissure, Horizontal fissure, pulmonary ligament

Question 20

What is the root/hilum of the lung?

Answer 20

The connective structures that join the mediastinal surfaces to the heart and trachea - all enveloped in pleura

Question 21

What are the structures that form the hilum?

Answer 21

Primary bronchus, Pulmonary artery/ (2x)veins, Bronchial arteries/veins, pulmonary plexus of nerves (autonomic), lymph vessels and nodes

Question 22

What is the pulmonary ligament used for?

Answer 22

Gives the lungs space to expand in the pleural cavity

Question 23

What is the pleura?

Answer 23

Thin layer of flattened cells supported by connective tissue that lines each pleural cavity and covers exterior of lungs

Question 24

How many layers for the pleura?

Answer 24

2: visceral (covers surface lungs and lines fissures between lobes) and parietal (lines inner surface of chest wall)

Question 25

What happens to the pleura at the hilum?

Answer 25

Visceral and parietal are continuous with each other

Question 26

How is the pleura in a healthy individual?

Answer 26

Pleural cavity is collapsed, but moist surfaces allow lungs to glide as the expand and collapse

Question 27

How are both layers of the pleura stuck together?

Answer 27

By surface tension

Question 28

What is the gestational origin of the pleura?

Answer 28

Buds from the laryngotracheal tube form and push into the coelomic cavities. Slowly the lungs grow into the cavity, with the cavity lining forming the parietal pleura and the lining which is pushed in by lungs, forms visceral , with pleural cavity in between

Question 29

Where do the lungs end?

Answer 29

Around the 6th rib

Question 30

Where does the pleural cavity end?

Answer 30

Around 8-10th ribs

Question 31

Why is there so much space between lungs and pleural cavity?

Answer 31

Called costo-diaphragmatic recess - to allow for space in maximal inspiration

Question 32

What is breathing controlled and produced by?

Answer 32

Controlled by NS and produced by skeletal muscle

Question 33

How can the capacity of the thoracic cavity be increased?

Answer 33

Movements of the diaphragm and ribs

Question 34

How does the mechanism of breathing work?

Answer 34

Pleural cavity is expanded by muscles in walls, then elastic lungs expand with it, sucking air down the trachea into the lungs

Question 35

What does contraction of the diaphragm do?

Answer 35

Increases vertical dimension of the thoracic cavity, by pushing the abdominal viscera down to a point. Then the costal margin is raised

Question 36

Where is the serratus anterior attached to?

Answer 36

Originates on the surface of upper 8/9 ribs and attaches to front border of scapula

Question 37

What does the serratus anterior do?

Answer 37

Allows forward rotation of arm and upward rotation of the arm by moving the scapula

Question 38

What happens when there's increased thoracic capacity?

Answer 38

Intrapleural pressure decreases and entry of air through respiratory passages into lungs, causing them to expand

Question 39

How is the diaphragm structured?

Answer 39

Ring of skeletal muscle from costal margin attached to tendinous sheet which stretches

Question 40

How high does the diaphragm stretch?

Answer 40

It stretches so high that organs like the liver are covered by the diaphragm, pleura and lung

Question 41

How do the ribs move in breathing?

Answer 41

When ribs elevate (ant ends thrust forward and upwards) ^ antero-posterior dimension of thoracic cavity AND at same time, ribs are everted ^ transverse diameter AND IIM and EIM stiffen rib cage for ^ efficiency of diaphragm

Question 42

Why does the costal margin rising help breathing?

Answer 42

It widens the pleural cavities by raising drooping lateral parts of ribs (bucket handle motion)

Question 43

What also occurs when costal margin raised?

Answer 43

Sternum is tilted upwards, ^ antero-posterior diameter of pleural cavities (Pump-handle motion)

Question 44

What kind of activity is quiet expiration?

Answer 44

Passive as it doesn't need muscle action

Question 45

What does quiet expiration depend on?

Answer 45

Elastic recoil in elastic tissue throughout lungs and rib cage

Question 46

How does deep/forced expiration occur?

Answer 46

Muscles in abdominal walls squeeze abdominal organs against diaphragm and pull lower ribs downwards