applied anatomy of the thorax

Question 1

what’s the largest muscle in the chest wall?

Answer 1

pectoralis major

Question 2

what actions can pectoralis major do?

Answer 2

flexion
adduction
internal rotation

Question 3

what are the attachment points of pectoralis major?

Answer 3

o Attaches to clavicle, sternum, ribs and humerus

Question 4

where is pectoralis minor found?

Answer 4

underneath pectoralis major

Question 5

where does pectoralis minor attach?

Answer 5

to the scapula and ribs

Question 6

what are the attachment points of sternocleidomastoid?

Answer 6

mastoid process

sternum and clavicle

Question 7

what nerve innervates the sternocleidomastoid?

Answer 7

spinal accessory nerve

Question 8

what are the attachment points of the rectus abdominis?

Answer 8

costal margin and xiphoid process

pubic symphysis

Question 9

what muscles are used in inspiration?

Answer 9

pec major, pec minor, SCM, external intercostals

Question 10

what muscle is used in forced expiration?

Answer 10

rectus abdominis

Question 11

what supplies the serratus anterior and what are the spinal levels?

Answer 11

long thoracic nerve C5-C7

Question 12

where does the long thoracic nerve run?

Answer 12

runs on the superficial border of the muscle

Question 13

what is the clinical relevance of the long thoracic nerve?

Answer 13

if you’re removing all the axillary lymph nodes in a radical mastectomy then it’s easy to damage this nerve  winging of the scapula

Question 14

how do intercostal nerves leave the spinal cord?

Answer 14

through the IV foramen

Question 15

where do posterior intercostal arteries branch from?

Answer 15

thoracic aorta

Question 16

where do anterior intercostal arteries branch from?

Answer 16

internal thoracic artery

Question 17

where do anterior intercostal veins drain?

Answer 17

into the internal thoracic vein

Question 18

where do posterior intercostal veins drain?

Answer 18

azygos –> superior vena cava

Question 19

where are neurovascular bundles found?

Answer 19

innermost intercostal layer and internal intercostal

Question 20

what is the pupose of thoracocentesis?

Answer 20

done to sample pleural fluid

Question 21

how is thoracocentesis done?

Answer 21

• Needle inserted superior to rib to avoid damage to intercostal nerves
• Upright patient will have fluid accumulate in the costophrenic recess
• 9th mid-axillary line during expiration avoids the inferior border of the lung

Question 22

what condition can a ruptured posterior intercostal artery caused?

Answer 22

haemothorax

Question 23

where is a chest drain done?

Answer 23

5th intercostal space in the mid-axillary line

Question 24

why does a chest drain happen higher in the chest than a thoracocentesis?

Answer 24

Happens higher up than thoracocentesis bc you’re trying to avoid the liver

Question 25

what nerve innervates the diaphragm?

Answer 25

phrenic nerve | C3-C5

Question 26

where does the vena cava enter the diaphragm?

Answer 26

T8

Question 27

where does the oesophagus enter the diaphragn?

Answer 27

T10

Question 28

at what level is the aortic hiatus?

Answer 28

T12

Question 29

what does the parietal pleura cover?

Answer 29

thoracic wall and superior surface of diaphragm

Question 30

what does the visceral pleura cover?

Answer 30

covers external lung surface

Question 31

where is the pleural cavity found?

Answer 31

between the pleural layers

Question 32

which pleural layer produces pleural fluid?

Answer 32

parietal pleura

Question 33

what is the function of pleural fluid?

Answer 33

o Reduce the friction when you breathe o Keeps the lungs stuck to the parietal layer oKeeps the lungs inflated

Question 34

explain the nerve supply of the visceral pleura

Answer 34

same as the lungs: sympathetic and parasympathetic. Not able to perceive pain

Question 35

explain the nerve supply of the parietal pleura

Answer 35

same as the chest wall: innervated by the intercostal nerves and the phrenic nerve. Can feel pain.

Question 36

what aspect of the chest wall are the intercostal nerves found?

Answer 36

lateral

Question 37

what aspect of the chest wall is the phrenic nerve found on?

Answer 37

medial

Question 38

when would you feel a tumour in the lung tissue?

Answer 38

when it got so big until it touched the parietal pleura

Question 39

on a normal chest x ray, should the pleura be visible?

Answer 39

no

Question 40

how is the costophrenic recess formed?

Answer 40

parietal pleura continues 2 ribs inferior to the lungs | ends up with a space under the inferior border of the lung

Question 41

why is it best to look for a pleural effusion using a lateral view?

Answer 41

Diaphragm is deeply domed so the deepest point of the CPR is at the back of the chest cavity.

Question 42

when can you see an effusion with a lateral view?

Answer 42

when there's about 100ml of fluid

Question 43

when can you see an effusion with an AP view?

Answer 43

need about 200ml of fluid

Question 44

where is the apex of the lungs?

Answer 44

2cm above the clavicles

Question 45

where is the cardiac notch?

Answer 45

4th rib

Question 46

where are the borders of the lungs found?

Answer 46

6th rib - MCL 8th rib - MAL 10th rib

Question 47

what are the pleural boundaries?

Answer 47

ribs 8, 10 and 12

Question 48

describe the respiratory tree

Answer 48

trachea - main bronchus - lobar bronchus - segmental bronchi - conducting bronchioles - terminal bronchioles - respiratory bronchioles - alveolar ducts - alveolar sacs

Question 49

describe the structure of the trachea

Answer 49

C shaped rings of cartilage anteriorly and smooth muscle posteriorly

Question 50

how is the right bronchus different to the left?

Answer 50

more vertical and larger

Question 51

what is the clinical relevance of the right bronchus being vertical?

Answer 51

anything aspirated is more likely to go to the right lung. Aspiration pneumonia is more likely to occur in the right lung

Question 52

how many lobar bronchi do we have for each lung?

Answer 52

3 lobar bronchi in the right lung | 2 lobar in the left

Question 53

how many ribs should you normally see above the diaphragm on an x-ray?

Answer 53

5-7

Question 54

how does hyper-expansion of the lungs look on an x-ray?

Answer 54

when more than 5-7 ribs can be seen above the diaphragm

Question 55

explain the process of emphysema?

Answer 55

* Destruction of alveolar walls leading to permanent enlargement of air spaces * Surface area dramatically reduced * Loss of elastic tissue so less recoil of the lungs * Narrowed bronchioles * COPD – emphysema

Question 56

why is there hyperextension of the lungs in emphysema?

Answer 56

o When air leaves the bronchioles, lungs will elastic recoi. o COPD – less elastic recoil and bronchioles aren’t supported by as much tissue bc it’s all been destroyed. Air cant leave  gets trapped o Air doesn’t get expired so the lungs become hyperinflated

Question 57

what divides the superior and inferior mediastinum?

Answer 57

angle of louis

Question 58

what does the superior mediastinum contain?

Answer 58

great vessels, oesophagus, trachea, thymus, phrenic nerves, vagus nerves, recurrent laryngeal nerves, thoracic duct

Question 59

describe the passage of the recurrent laryngeal nerve in the body?

Answer 59

branch of vagus nerve which loops around the arch of the aorta on the left and the subclavian artery on the right. Runs back up to the larynx where it supplies the vocal cords

Question 60

where is the posterior mediastinum?

Answer 60

• Anterior to vertebrae T5-T12, inferior to sternal angle and posterior to pericardium

Question 61

what does the posterior mediastinum contain?

Answer 61

azygos (and hemi-azygos), vagus, oesophagus, thoracic duct, thoracic aorta

Question 62

what spinal levels are the sympathetic chain ganglion?

Answer 62

T1-L2

Question 63

what does the sympathetic trunk control?

Answer 63

fight or flight response; pupil dilation, bronchodilation, cardiac acceleration, inhibition of digestion, filling of the bladder, peripheral vasoconstriction, piloerection