Lecture 6: Lungs and pleura

Question 1

What are the divisions of the thoracic caivty?

Answer 1

• Right hemithorax (R lung) - Left hemithorax (L lung) - Mediastinum -> Heart and related structures

Question 2

What lines the chest cavities?

Answer 2

Pluera! (also opportunity for pathologies

Question 3

What are the pleura of the chest cavity?

Answer 3

Visceral pleura (outer surface lungs) Parietal pleura (Lining pulmonary cavity) ENDOTHORACIC FASCIA Pulmonary ligament

Question 4

What is the endothoracic fascia?

Answer 4

• Adheres costal parietal pleura to thoracic wall - Continuous with fibrous supraplueral membrane

Question 5

What is the pulmonary ligament?

Answer 5

Sleeve of pleura hanging down from lung root

Question 6

What innervates the visceral pleura? whats its sensitivity to pain?

Answer 6

ANS - T1-4 sympathetic - Vagus (CN X) (Insensitive to pain, this is referred)

Question 7

What innervates the parietal pleura? Whats its sensitivity to pain?

Answer 7

• Intercostal nerves - Phrenic nerve (C3-5 keeps the diaphragm alive) Sensitive to pain, localised pain

Question 8

What keeps the diaphragm alive?

Answer 8

C3,4,5 keep the diaphragm alive

Question 9

For the surface markings of pleura and lungs what are the landmarks in relation to?

Answer 9

The landmarks are in relation to the ribs not the vertebral level

Question 10

What are some surface markings of the lungs?

Answer 10

Lungs (up in 2’s) (This is where the base is found depending on which angle you are on) - Midclavicular line rib 6 (Front) - Mid-axillary line rib 8 (Side) - Scapular line rib 10 (Back)

Question 11

What are some surface markings of the pleura?

Answer 11

Pluera (up in 2’s) (This is where the pleura base should be depending on what angle you are on) - Mid-clavicular line rib 8 (Front) - Mid axillary line rib 10 (Side) - Scapular line rib 12 (Back)

Question 12

What are the recesses of the lung and what does this mean?

Answer 12

• Costodiaphragmatic recesses (Post-lower ribs) - Costomediastinal recesses These are potential spaces…

Question 13

Discuss the importance of the costodiaphragmatic recesses;

Answer 13

• A potential space filled on inhalation - Fluid can accumulate and blunt the costodiaphragmatic angle // prevent lung expansion

Question 14

What are the lobes and fissures of the left lung?

Answer 14

• Sup and inf. lobes - Oblique fissure

Question 15

What are the lobes and fissures of the right lung?

Answer 15

• Sup, middle and inferior lobes - Oblique and transverse fissures

Question 16

Whats of note about fissures?

Answer 16

They can fuse with age but remain functionally seperate

Question 17

Describe the surfaces of the lung

Answer 17

Question 18

Describe the bronchopulmonary segmentation beginning with the trachea;

Answer 18

Trachea -> Main bronchi -> Lobar bronchi -> Segmental bronchi (x10)

Question 19

At what level is the carina found?

Answer 19

T4/5 // transthoracic plane

Question 20

What is of notable difference between the main bronchi?

Answer 20

Different angles // right is larger and aspiration pneumonia is more common here, it is also on a different angle

Question 21

What are the ANS pulmonary plexuses?

Answer 21

There are: - ANT and POST plexus around carina, post larger Comprised of Parasymp (VAGUS) and Symp (T2-4) (Thoracic ganglia)

Question 22

What are the somatic plexus of the pulmonary space? and what do they do>

Answer 22

• Intercostals = Pain in body wall and parietal pleura = Motor to intercostals - Phrenics (C3-5) = Diaphragm control (mixture of ANS and Somatic b/c can occur autonomically and consciously)

Question 23

What are the notable lymphatics of the lungs?

Answer 23

1) Paratracheal nodes 2) Thoracic duct and right lymphatic duct 3) (Bronchopulmonary) hilar nodes 4) Carinal nodes

Question 24

Where does chest / lung pain present?

Answer 24

Phrenic nerve = C3-5 dermatome Intercostals nn = Specifically localised ANS T1-4 = Referred to T1-4 dermatomes T4 = nipples

Question 25

Describe the flow of blood through the lungs from the heart, commenting on blood oxygenation;

Answer 25

Deoxygenated blood leaves right ventricle -> Pulmonary trunk -> Pulmonary arteries (x2) = Oxygenated in lung tissues -> Pulmonary veins (x4) -> Into left atrium and onto systemic circulation

Question 26

What supplies the lung tissues with blood and nutrients?

Answer 26

Bronchial arteries (x2 LHS and x1 RHS) Come off aorta…

Question 27

Whats of note about the anatomical route of the left main bronchus?

Answer 27

It crosses 3 structures

Question 28

What are bronchopulmonary segments?

Answer 28

10 segments per lung - Smallest functionally independant region of a lung Each segment has; - A segmental bronchus - A pulm. artery - Bronchial art. branch Veins and lymphatics can be seen along edge of these segments Separated by thin CT

Question 29

What happens in a patient with a patent ductus arteriosus?

Answer 29

Blood travels from aorta -> ductus arteriosus -> pulmonary trunk -> Lungs Depending on patency size - Can increase BF to lungs = pulm. hypertension / oedema - Decrease systemic blood flow = organ damage - Increase heart work

Question 30

What can a patent foramen ovale lead to?

Answer 30

• Potentially silent (~25%) BUT could lead to; - Lower than normal O2 levels in arterial blood - Pulm. hypertension (Thicking of pulm art. -> RHS hypertrophy -> HF or reversal of patency flow and cyanosis)

Question 31

What are the unique features of the fetal bypass system?

Answer 31

Lungs filled with fluid therefore pulmonary circulation has high resistance, in addition to; - Ductus arteriosus which redirects pulmonary trunk blood to the aorta - Foramen ovale which shunts blood from RA -> LA - Blood is oxygenated in the placenta, this returning blood drives straight to the LA to give highly oxygenated blood to the head. - Returning deoxygenated blood from the legs flows into the RA->RV - Some mixing of blood occurs in the aorta b/c of the ductus arteriosus

Question 32

Answer 32

Question 33

Answer 33

Question 34

Answer 34

Question 35

Answer 35

Question 36

Answer 36