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
tripod position
pts w/ advanced lung disease –> leaning forward, hands on knees to optimize respiratory mechanics
bucket-handle movement
external intercostal muscles contract and elevate rib cage, expands laterally
pump-handle movement
raising and lowering of sternal end of rib
quiet expiration
passive inspiratory muscles relax rib cage drops under force of gravity relaxing diaphragm moves up elastic fibers in lung recoil volumes of thorax and lungs decrease simultaneously, increasing the pressure air forced out
forced expiration
use muscles of anterior and wall to compress viscera up under diaphragm
intercostal n.
ventral primary rami of spinal n. T1-T12
travel between internal intercostals and innermost intercostals
motor innervation to muscles of intercostal space
severe coarctation of aorta
collateral circulation involving internal thoracic and intercostal arteries occurs
may result in enlargement of intercostals and “rib notching” on inferior edge of upper rib
figure 3 sign –> formed by dilatation of the aortic arch and
2 terminal branches of internal thoracic artery
musculophrenic artery
superior epigastric artery
ligaments attaching ribs to vertebrae
costovertebral ligaments
ligaments rib-rib
costotransverse ligaments
costochondritis
comm cause of chest pain in children and adolescents
inflammation of sternocostal ligaments (synovial ligaments)
Thoracocentesis
in midaxillary line to avoid intercostal n. and collateral branch
anterior intercostal veins drain into
internal thoracic veins
posterior intercostal veins drain into
azygous system of veins
Compartments of thoracic cavity
2 pulmonary cavities (lungs and pleurae)
central compartment - mediastinum (heart, great vessels, trachea, esophagus)
R lung
3 lobes
horizontal fissure
oblique fissure
L lung
oblique fissure
cardiac notch
lingula
parietal pleurae lines the
thoracic cavity
visceral pleurae
covers surface of lungs
pain from mediastinal and diaphragmatic pleurae may be referred to shoulder dermatome (C3, C4) because of innervation by….
phrenic nerve
pleurisy
inflammation of pleura (parietal and visceral rub together)
sharp pain during breathing, coughing, sneezing
causes: viral/bacterial infections (pneumonia, TB), pneumothorax, palm embolism, lung cancer
can cause pleural effusion
first place pleural effusion will occur
buildup of fluid particularly in costodiaphragmatic recess
lungs extend ot ribs … during quiet respiration, pleural reflections to ribs…
lungs to ribs 6, 8, 10
pleural reflections to ribs 8, 10, 12
types of fluid that can accumulate in pleural space
serous fluid (hydrothorax, pleural effusion) blood (hemothorax) lymph (chyle - chylothorax) pus (prothorax or empyema) air (pneumothorax)
pleural effusion
costodiaphragmatic angle on affected vs. unaffected side
sharp on unaffected side
blunt on affected side
common cause of spontaneous pneumothorax in young children and adults
pulmonary blebs (weakened out-pouching in lung, can rupture)
other causes: chest injury, lung disease (pneumonia, COPD)
tension pneumothorax
air enters pleural cavity during inspiration but not expelled during exhalation
L side tension pneumothorax causes increased volume of air within pleural space can cause MEDIASTINUM SHIFT to R side. inc pressure within chest cavity –> dec systemic venous return –> dec systemic venous return to heart –> dec cardiac output
findings: chest pain, respirator distress, tachycardia, tachypnea (in initial stages)
pneumothorax
injury to parietal or visceral pleurae or lung –> air into pleural cavity
mucosa covering carina is innervated by sensory fibers that trigger…
cough reflex
R and L pulmonary a. divide into ______, then _______ (usu 10 in each lung).
R and L pulmonary a. –> lobar a. –> segmental a. (10 each lung)
pulmonary veins enter into
LA
bronchial a.
usually branches of posterior intercostal a. or from aorta itself
carry oxygenated blood, travel along bronchi and pulmonary a. to provide blood to bronchi/tissue
lung root
sheath of parietal pleura, conjoins the pericardium, and encloses pulmonary a., v., main bronchus, lymph nodes, and autonomic nerves
pulmonary embolism sx/clinical signs/tx
difficulty breathing, chest pain upon inspiration
low oxygen levels, cyanosis, rapid breathing, rapid heart rate
anticoagulants and thrombolytics
pulmonary plexus
supplies smooth muscles, glands in lungs/airways w/ autonomic innervation
R/L vagus n. (CN X)
R/L sympathetic chain
cardiopulmonary splanchnic n.
carry POSTGANGLIONIC SYMPATHETIC fibers to heart/lung/esophagus
via IML cell column
vagus n. (CN X)
parasympathetic
in pulmonary plexus
constricts smc in bronchi
secretion of mucous glands
relaxes blood vessels
sympathetic fibers of pulmonary plexus
relax smooth muscle in bronchi (bronchodilator)
inhibit secretion of mucous
constrict blood vessels
exp. albuterol
Right main-stem bronchus (eparetial bronchus) is found superior to the…
pulmonary artery
bronchopulmonary (hilarious) lymph nodes can often be seen here, and on rare occasion also small bronchial arteries
left pulmonary a. lies above…
left main stem bronchus
R lung hilum vs. L lung hilum
RALS
R
A (anterior pulmonary a.)
L
S (superior pulmonary a.)
Where does lymph from L lower load drain into?
Lymphatics on R side
superior thoracic aperture
aka thoracic outlet
Between T1 and manubrium
inferior thoracic aperture
bound by costal margin and lower ribs
