Thoracic cage and mechanics of breathing

Question 1

what level is the suprasternal notch?

Answer 1

T2/3

Question 2

what level is the sternal angle of Louis?

Answer 2

T4/5

Question 3

what level is the inferior angle of scapula?

Answer 3

T8

Question 4

what level is xiphisternum

Answer 4

T9

Question 5

what level is the lowest part of costal margin, 10th rib?

Answer 5

L3

Question 6

what are false ribs?

Answer 6

free ribs - 11 and 12

Question 7

what are true ribs?

Answer 7

7,8,9

Question 8

which ribs are most likely to fracture?

Answer 8

7-10

Question 9

which ribs are least likely to fracture?

Answer 9

1 and 2 and 11 and 12

Question 10

where is the weakest part of the rib?

Answer 10

middle/ side

Question 11

fracture caused by coughing

Answer 11

pathological fracture

Question 12

rib fractures in children

Answer 12

rare because bones are elastic and flexible

Question 13

what do the lower ribs protect?

Answer 13

liver, spleen, diaphragm, abdominal viscera

Question 14

thoracic outlet syndrome

Answer 14

C8 and T1 become compressed in the thoracic outlet, affecting the ulnar nerve . Unable to do fine movements of hand and flexion at wrist . Causes tingling in hands, white/ pale arms if subclavian artery compressed or blue arm if subclavian vein compressed

Question 15

where is the apex of the lung?

Answer 15

comes out above clavicle

Question 16

what could obstruct the superior thoracic aperture?

Answer 16

extra ribs (cervical) above 1st rib
abnormal tight band connecting the spine to the ribs

Question 17

anatomy of thoracic vertebrae

Answer 17

12 thoracic vertebrae
medium sized
main function - to articulate with the ribs
each thoracic vertebra has 2 demi facets
costal facet is on the transverse process except T11 and 12 which articulate with the tubercle of the rib

Question 18

Pressures at rest

Answer 18

atmospheric = 760mmHg
Alveolar pressure = 760mmHg
Intrapleural pressure = 756mmHg

Question 19

pressures during inhalation

Answer 19

atmospheric = 760mmHg
Alveolar = 758mmHg
Intrapleural = 754mmHg

Question 20

level of diaphragm

Answer 20

T9 posteriorly
anteriorly level of 5th rib
higher on left due to the liver

Question 21

diaphragmatic movement

Answer 21

increases vertical diameter of thoracic cavity .
contraction during inspiration causes it to flatten and moves downward leading to increase in the vertical diameter of thoracic cavity .

Question 22

what are the most active muscle group in breathing?

Answer 22

diaphragm/ skirt

Question 23

Inspiratory muscles during quiet breathing

Answer 23

diaphragm

external intercostals stabilise rib cage and move ribs up and out to increase diameter of thorax .

Question 24

Inspiratory muscles during increasing effort

Answer 24

diaphragm
external intercostals move the ribcage up and out
neck muscles pull ribcage upwards
sternocleidomastoid elevate sternum and scalenus major and minor muscles elevate first 2 ribs and sternum
shoulder muscles will pull rib cage outwards > pecs and lat dorsi

Question 25

what are the muscles of inspiration?

Answer 25

``` diaphragm external intercostals accessory muscles= sternocleidomastoid, anterior, middle and posterior scalenes pectoralis major and minor serratus anterior ```

Question 26

expiratory muscles in quiet breathing

Answer 26

elastic recoil of tissues - chest wall and lungs. Normal exhalation is a passive process

Question 27

expiratory muscles in increasing effort

Answer 27

becomes an active process and involves internal intercostals and abdominal wall muscles

Question 28

what muscles are involved in expiration

Answer 28

internal and innermost intercostals | accessory muscles = rectus abdominis and transversus abdominis, external and internal oblique

Question 29

what do the internal and innermost intercostals do in expiration

Answer 29

internal = depress interosseus parts of ribs during forced expiration elevate interchondral parts of ribs during forced expiration

Question 30

what do the accessory muscles of expiration do in expiration?

Answer 30

fix costal margin and increase intra-abdominal pressure

Question 31

mechanics of movement

Answer 31

pump handle movement - increases the antero-posterior diameter of thoracic cavity. Upward movement of the upper ribs move the sternum upward and outward and increases the antero-posterior diameter of thoracic cavity . bucket handle movement = increases the transverse diameter of the thoracic cavity . Upward and outward movements of the middle and lower ribs increase the transverse or lateral diameter of thoracic cavity .

Question 32

what are the most active muscle groups in the pump handle movement?

Answer 32

intercostals

Question 33

what are the most active muscle groups in the bucket handle movement?

Answer 33

intercostals

Question 34

what innervates the diaphragm?

Answer 34

phrenic nerves

Question 35

what innervates the intercostal muscles?

Answer 35

segmental thoracic nerves

Question 36

what is the nerve root of the phrenic nerve?

Answer 36

C3,4,5

Question 37

upper and lower surfaces of ribs

Answer 37

``` upper = blunt lower = sharp ```

Question 38

fractured rib from coughing

Answer 38

pathological rib fracture

Question 39

cervical pleura

Answer 39

above first rib

Question 40

structure of pleura

Answer 40

cervical pleura above first rib space for root of lung pleura named based on what it is touching

Question 41

what goes through the diaphragm?

Answer 41

inferior vena cava oesophagus aorta

Question 42

Azygos system

Answer 42

veins that drain the thoracic wall and upper lumbar region via the lumbar veins and posterior intercostal veins

Question 43

what type of muscle is the diaphragm?

Answer 43

fast twitch

Question 44

not exercising with a respiratory condition

Answer 44

may use all the breathing muscles despite not exercising .

Question 45

thoracic interventions

Answer 45

go above rib for pleural fluid insert chest drain above rib to avoid the artery and vein at anaesthetise the rib insert needle below the rib to hit the nerve

Question 46

phrenic nerve palsy

Answer 46

causes hemidiaphragm, one side raises up

Question 47

Injury to C5

Answer 47

patient will still be able to breathe but not move anything else

Question 48

Injury to C2

Answer 48

no movement | patient will have to be on ventilator