Thoracic cage and breathing mechanisms Flashcards
Where is tip of scapula?
T8
Where is manubrio-stinal joint
T4/6
Where does aorta intersect diaphragm?
T12
Which ribs are least injured?
1,2,11,12
Why is diaphragm higher on right?
Liver
Which nerve supplies diaphragm?
Phrenic
What is the hiatus?
Base of diaphragm, oesophagus, IVC and aorta go through
What is the azygous vein?
Inter-costal veins drain here
Innervation of phrenic nerve
3,4,5
Is expiration passive or active?
Passive
How to feel bucket handle?
Put hands under armpit around ribs
Inspiration
Phrenic nerve stimulates diaphragm to contract
External intercostals contract to elevate ribs
Accessory muscles of inspiration and their functions
Sternocleidomastoid - elevates sternum
Scalenes - fix 1 and 2 ribs
Pec maj and min - fix ribs 3,4,5 when scapula stabilised
Serratus anterior - when scapula stabilised, fixed 8 or 9 upper ribs
How to tell if someone has COPD
They use neck muscles to breathe
Expiration
Elastic recoil of chest wall and lungs = passive
Diaphragm and external intercostals relax
Accessory muscles of expiration
Rectus and transversus abdominis
Increase intra-abdominal pressure
What does pump handle do?
Increase front to back distance of chest
What does bucket handle do?
Lateral ribs
Pulmonary syndrome
Absence of pec major and sometimes ribs
C2 lesion
Can’t use diaphragm or intercostals, no BP so ventilator
C5 lesion
Diaphragm but no BP
T2 lesion
Diaphragm and BP but not intercostals
L1 lesion
Diaphragm and intercostals work but paralysed
