Thoracic wall and lung Flashcards
anterior axillary line
vertical line through anterior axillary fold
lat edge of pectoralis major
posterior axillary line
vertical line through posterior axillary fold
ant edge of latissimus dorsi
aortic valve auscultation site
2nd intercostal space just to right of sternum
pulmonary valve auscultation site
2nd intercostal space just to left of sternum
tricuspid valve auscultation site
5th intercostal space just L to sternum
mitral valve auscultation site
left 5th intercostal space in midclavicular line
thoracic cage expands/contracts, thus inc/dec
intrathoracic pressure
inhale –> intercostal m. and diaphragm contract to expand chest cavity. diaphragm flattens and moves downwards and intercostal m. move rib cage up and out
inc in size –> dec internal air pressure, air from outside (now at higher P than inside thorax) rushes into lungs to equalize pressures
Exhale –> diaphragm and intercostal m. relax, reduces size of thoracic cavity thus increasing pressure and forcing air out of lungs
external intercostal muscles are replaced anteriorly by…
external intercostal membrane
internal intercostal muscles are replaced posteriorly by…
internal intercostal membrane
internal thoracic vessels are lateral to …
sternum
true ribs
(1-7) attach directly to sternum
false ribs
8-10 attach to costal cartilage above
floating ribs
11, 12 no cartilage
no necks or tubercles
paravertebral line
runs down transverse processes
scapular line
runs vertically down scapula
right semi-diaphragm is where during expiration
at about the 4th intercostal space
7th rib articulates with …
7th vertebral body
6th vertebral body above
intervertebral disc
flail chest
effects on inspiration/expiration
multiple rib fractures –> section of rib cage becomes detached from rest of the chest wall
inspiration –> intapleural pressure becomes increasingly negative, flail segment and underlying tissue sucked inward, lung collapses on affected side, mediastinum shifted toward unaffected side
expiration –> intrapleural pressure becomes less negative, flail segment and underlying tissue are pushed outward, mediastinum shifts to affected side
cervical rib may compress…
…subclavian/brachial artery between anterior scalene m. and cervical rib –> loss of pulse when arm is aBducted
…lower trunk of brachial plexus –> weakness in muscles of hand, pain, numbness in medial side of forearm and hand
^cause form of THORACIC OUTLET SYNDROME
(cervical rib=extra rib, usually arises from 7th cervical vertebra)
pectus excavatum
funnel chest
pectus carinatum
pigeon chest
kyphoscoliosis
lat bending
xs curvature
external intercostal m. action
elevate rib below during inspiration, expand vol of thoracic cavity which decreases inter thoracic pressure below atmospheric pressure and draws air into lungs
which arteries/veins run between transversus thoracis m.?
branches of internal thoracic a. and v.
internal thoracic a. arises from first part of subclavian a.
phrenic n.
C3, 4, 5
motor innervation of diaphragm
sensory innervation of diaphragm, pleura, pericardium, inferior vena cava, and peritoneum
Diaphragm during inspiration
during quiet inspration, diaphragmflattens as it contracts –> increases height of thoracic cavity
External intercostal muscles during deep inspiration
contract during deep inspiration to raise the ribs –> inc circumference of thoracic cavity
accessory m. of respiration that add extra increase in volume
scalenes sternocleidomastoids pec. major/minor serratus anterior obliques transversus thoracis transversus abdominus rectus abdominus