thoracic wall Flashcards
thorax
upper part of the trunk, extending from the root of the neck to the abdomen
thorax basic boundaries
- super ior thoracic aperature (roof)
- inferior thoracic aperature (floor)
- thoracic wall
thorax contents
- heart
- lungs
- mediastinum
thorax functions
- respiration
- vital organ protection
- conduit for structures passing to/from neck and abdomen
- breast tissue support
respiration
- movements of the thoracic wall increase/decrease intrathoracic volume
- result in inspiration/expiration
thorax vital organs
- heart
- lungs
- liver
-spleen - kidneys
structures passing to/from neck and abdomen
- nerves
- blood vessels
- lymphatics
- trachea
- esophagus
thoracic lines
- anterior thoracic lines
- axillary lines
- posterior thoracic lines
sternal landmarks
- suprasternal notch
- sternal angle
- xiphosternal joint
- xiphoid process
- infrasternal angle
erb’s point clinical importance
2nd heart sound (lub “dub”)
ekg lead placement names
V1, V2, V3, V4, V5, V6
V1 ekg place
- 4th intercostal space
- right side of sternum body
V2 ekg place
- 4th intercostal space
- left side of sternum body
V3 ekg place
- 5th intercostal space
- 50% distance of V2 and V4
V4 ekg place
- 5th intercostal space
- midclavicular
V5 ekg place
- 5th intercostal space
- anterior axillary
V6 ekg place
- 5th intercostal
- midaxillary
thoracic wall components
- bones, muscle, fat
- 12 thoracic vertebrae (typical and atypical)
- 12 pairs of ribs with costal cartilage (typical and atypical)
- sternum (manubrium, body, xiphoid process)
- intercostal spaces
- endothoracic fascia
- parietal and visceral pleura
intercostal spaces
- lie between ribs
- contain. 3layers of muscles and neurovasculature bundle
sternum parts
- manubrium
- body
- xiphoid process
endothoracic fascia
- loose ct
- deep to intercostal spaces and ribs, separates them from underlying pleura
- outermost membrane of thoracic cavity
where and why does thoracic wall thicken
- over top of each lung as suprapleural (sibson’s fascia) membrane
- where it attaches to the internal border of first rib and transverse process of C7
skeletal structures of the thorax form ?
thoracic cage
thoracic cage components
- 12 thoracic vertebrae
- 12 ribs
- sternum (manubrium, body, xiphoid process)
12 ribs
- true ribs: 1-7
- false ribs: 8-12
- floating ribs: 11, 12
true ribs
direct costal cartilage connected to sternum
false ribs
costal cartilage joins to adjacent costal cartilage (not sternum)
floating ribs
no costal cartilage
which thoracic vertebrae are typical
T2-T8
typical thoracic vertebrae features
- heart shaped body
- super and inferior demi-facets on both sides of body
- costal facets on transverse processes
- long downward slanting spinous processes
which thoracic vertebrae are atypical
T1, T9-T12
atypical thoracic vertebrae features
- superior facet is costal (not demi)
- no inferior demi facet
which ribs are typical
2-9
typical rib features
- flat, curved, minorly twisted costal groove
- blunt arrow-head shape
- articular facet has a costal facet on transverse process
costal groove on rib purpose
protects and holds artery, vein, nerve bundle
atypical rib 1 features
- shorter and wider
- only one facet
- superior surface allows subclavian vein and artery
atypical rib 2 features
- 2x length of rib 1
- 2 facts
- roughened superior surface
- origin of serratus anterior muscle
- insertion of posterior scalene muscle
which ribs are atypical
1, 2, 10-12
atypical rib 11, 12
- 1 facet
- no arrowhead
thoracic joints
- sternocostal joint (true ribs)
- costochondral joint
- interchondral joint
- xiphisternal joint
- manubriosternal joint (angle of Louis)
- sternoclavicular joint
- costovertebral joint
- costotransverse joints
sternocostal joint
- rib 1: primarily cartilaginous
- ribs 2-7: plane synovial
- stabilized by sternocostal ligaments and thin capsule
- slight gliding movements
costochondral joint
- primarily cartilaginous
- no movement, hyaline cartilage
- may inflame (costochondritis)
interchondral joint
- between 8th, 9th, 10th ribs
- plane synovial joints
- stabilized by interchondral ligaments and thin capsule
- may inflame
xiphisternal joint
- secondary cartilaginous (symphysis)
- usually ossifies later in life
manubriosternal joint (angle of Louis)
- secondary cartilaginous
- 162 degrees
- little movement
sternoclavicular joint
- synovial saddle joint
- anteroposterior and verticular planes
- minor rotation also occurs
- stabilized by anterior and posterior sternoclavicular, interclavicular and costoclavicular ligaments
costovertebral joint
- 2 plane synovial joints
- articulations of the demifacets on the head of each rib with the bodies of its corresponding vertebra and the one above
- 1st, 10th, 11th, 12th ribs have a single synovial joint with their corresponding vertebral bodies
- gliding movements
- stabilized by capsular, radiate, intra-articular ligaments
costotransverse joints
- 2 plane synovial joints formed by the articulations between facets on the rib tubercle and the transverse process of its vertebra
- 1-10 ribs only
- simple rotational and sliding motions
- stabilized by capsular, inferior cotransverse, superior costotransverse, lateral costotransverse ligaments
which 2 joint movements are simultaneous
- costovertebral joint
- costotransverse joint
primary respiration muscles (inhalation)
- diaphragm
- external intercostal muscles
accessory respiration muscles (inhalation)
- sternocleidomastoid muscle
- scalene muscles
- pectoralis minor muscle
- serratus anterior muscle
accessory respiration muscles (exhalation)
- internal intercostal muscles
- transverse thoracis muscle
- external oblique muscle
- rectus abdominis
- internal oblique muscle
intercostal muscles (outer to inner)
- external intercostal
- internal intercostal
- innermost intercostal
muscles in transverse thoracis group
- subcostalis
- transverse thoracis
- innermost intercostal
intercostal arteries enter the intercostal space anteriorly or posteriorly
both
1st and 2nd intercostal space supplied by ? artery
superior intercostal artery
superior intercostal artery origin
costocervical trunk
intercostal spaces (excl. 1st and 2nd) are supplied by ?
descending aorta
6 upper intercostals supplied by branches of the ?
internal thoracic artery
intercostal spaces 7-9 supplied by ?
musculophrenic branch
musculophrenic branch is a branch of ? artery
internal thoracic artery
venous drainage
in each space there are one posterior and two anterior intercostal veins plus one collateral vein
anterior vein drains into ?
musculophrenic and internal thoracic veins
posterior veins drain into ?
- azygos vein (right)
- hemiazygos and accessory hemiazygos vein (left)
lymphatic drainage pathway
- thoracic wall drain to parasternal/intercostal and diaphragmatic nodes
- parasternal drains to bronchomediasteinal
- intercostal drains to thoracic duct
thoracic wall layers (outer to inner)
- skin
- superficial fascia
- serratus anterior muscle
- external intercostal muscle
- internal intercotal muscle
- innermost intercostal muscle
- intercostal vein, artery, nerve/collateral branches
- endothoracic fascia
- parietal pleura
- pleural cavity
- visceral pleura
- lung
simple clinical issues
- costovertebral dislocation
- transverse rib fracture
- oblique rib fracture
- overriding rib fracture
- chondral fracture
- costochondral seperation
- chondrosternal seperation
- sternal fracture
complicated clinical issues
- trauma to pleura of lung (pneumothorax, lung contusion, subcutaneous emphysema)
- multiple rib fractures
- hemothorax (tear of blood vessel)
- compound by missile or puncture wound
- injury to heart or great blood vessel
