Thoracic Wall & Pleura
True ribs
(vertebrosternal) 1st - 7th, connect to the sternum via costal cartilage
Posterior intercostal arteries
1st & 2nd Superior (supreme) intercostal artery, 3rd - 11th Thoracic or Descending aorta
Superiorly
Air removal: tube directed (inferiorly or superiorly) towards the cervical pleura.
Intercostal Nerve Block
Anesthetic drug must infiltrate the space between the internal and innermost intercostal muscles to reach the intercostal nerves.
Pectus excavatum
Concave depression. Causes: • Intrauterine pressure on the chest wall during development. Complications: • Compression of heart & lungs
1, 12
Costal parietal pleura innervation is ___ st thru __ th intercostal nerves.
Pneumothorax
Entry of air into the pleural cavity
Azygos /Hemiazygos
Posterior intercostal veins drain into the _______ system
Ventral (anterior)
_____ rami supply the intercostal spaces
Paradoxical
different from what is expected (paradoxical motions)
Passive Expiration
elastic recoil of the lungs
Hydrothorax
excess fluid into the pleural cavity
Thoracic (descending) aorta
gives rise to 3rd = 11th posterior intercostal aa.
Safe triangle
ideal site for chest tube between 5th or 6th intercostal space.
Viscera/l
organs in the body cavity (in this lecture, the lungs)
Pleura
pair of serous membranes lining the thorax and enclosing the lungs
Pleural cavity
potential space between the parietal and visceral pleura
Pyothorax
pus into the pleural cavity
Phrenic
related to diaphragm
Costal
rib
Collateral
running side by side
Azygos system
unpaired veins that drain posterior thoracic wall
Passive inspiration
used mainly diaphragm and external intercostal m. regardless of the level of breathing
Active Inspiration
uses accessory muscles (Sternocleidomastoid m. , Scalene m. , Serratus anterior m., Pectoral m.)
Transverse thoracic muscles
(span 2nd -6th intercostal spaces), Muscle fibers run in different direction from those of the innermost intercostal mm.
Subcostal muscles
(span intercostal spaces), Muscle fibers orientation similar to the innermost intercostal mm.
Floating ribs
(vertebral) 11th & 12th, no connection with sternum; terminate in the posterior abdominal muscles
False ribs
(vertebrochondral) 8th - 10th, connect to costal cartilages of the ribs directly above them
Anterior intercostal arteries
1st - 6th Internal thoracic artery, 7th - 9th Musculophrenic artery
Manubriosternal joint
2nd rib articulates with the sternum at the ________
Xiphisternal joint
7th rib articulates with the sternum at the _______
Flail chest
A life threatening unstable injury of the thoracic wall. Multiple ribs fractures detach part of the thoracic wall from the rib cage. The detached part is subjected to unopposed intra-pleural pressure resulting in paradoxical motion seen during the breathing cycle.
Endothoracic fascia
A loose connective tissue that separates the inner surface of the thoracic wall and the parietal pleura (acts like glue between the parietal pleura and thoracic wall). forms an important natural cleavage plane for surgical separation of parietal pleura from thoracic wall.
Superior-inferior dimension
As the diaphragm contracts, the diaphragmatic dome flattens.
Inferiorly
Fluid removal: tube directed (inferiorly or superiorly) towards the costodiaphragmatic recess.
Sternum
Forms the anterior part of the Thoracic cage. Protects the Superior Mediastinal structures.
Pleuritis
Inflammation of pleura. Associated with sharp chest pain with deep breath or cough (irritation of parietal pleura innervated by the intercostal nerves). Pleura rub against each other. Detectable during auscultation as rough, grating sound similar to sound produced by rolling hair between fingers.
Thoracentesis / Thoracocentesis
Inserting a needle into the pleural cavity to obtain samples of fluids. Needle inserted midway within the intercostal spaces to avoid damaging the nerves (intercostals & collaterals branches
Pulmonary ligament
Loose fold of mediastinal pleura inferior to the root of the lungs. Allows movement of pulmonary vessels and bronchi during respiration.
Phrenic nerve (Anterior rami of C3, C4, C5)
Mediastinal pleura & pericardium: Diaphragmatic pleura (domes) toward the center of the diaphragm. (Pain referred to the root of the neck and the shoulder region)
Anteroposterior dimension
Movement Primarily involves 2nd-6th ribs. Convexity & concavity at the Costotransverse joints allow rotational moment. Pump and Handle movement
Lateral dimension
Movement Primarily involves mid thoracic ribs 7th-10th. Flat Costotransverse joint surfaces allow gliding movement). Bucket Handle Movement.
Pleurodensis
Obliterating (closing) the pleural space. Can be done surgically, mechanically or pharmacologically. Used in treatment of recurrent pleural effusion or pneumothorax.
Innermost intercostal muscles
Occupy lateral most part of the intercostal spaces. Muscle fibers run inferiorposteriorly. Separated by the intercostal neurovascular structures.
6, 12
Peripheral parts of the diaphragm innervated by ___ th - ___ th intercostal nerves. (Sensitive to pain, temperature, touch and pressure. Associated with localized sharp pain = somatic sensation)
Internal intercostal muscles
Span from the sternum to the angle of ribs. Muscle fibers run inferiorposteriorly Run deep and right angled to the external intercostal m. fibers
Extrinsic muscles
Stabilizes and moves pectoral girdle, upper limbs and neck
Chest tube / Chest drain
To remove excess fluid, blood, fluid, pus or air. Ideal sites 5th or 6th intercostal space (at nipple line) along the midaxillary line (Below this level can potentially damage the diaphragm)
parasympathetic fibers
Ventral rami contain mixed fibers (sensory, motor & sympathetic fibers; but NO_________ _______)
Insensitive, autonomic
Visceral pleura (surrounding the lung): (sensitive or Insensitive) to pain because its innervation is (somatic or autonomic).
Mediastinal
______ pleura covers the lateral sides of the mediastinum.
Cervical
_______ pleura covers the apex of the lungs (superior to the 1st rib & Superior Thoracic Aperture).
Anterior, posterior
________ intercostal and _________ intercostal arteries anastomose around the midclavicular line.
Hemopneumothorax
air and blood into the pleural cavity
Anterior axillary line
anterior axillary fold (inferolateral border of p.major)
Brachiocephalic vein
any artery that is a branch of the subclavian artery, the accompanying veins drain into the ________.
Midaxillary line
apex of axilla
Superior (supreme) intercostal a
arises from subclavian artery, gives rise to 1st & second posterior interocostal aa.
Parietal
belonging to the wall (in this lecture, the thoracic wall)
Hemothorax
blood into the pleural cavity
Pectus
chest
Endothoracic
connective tissue (attaches parietal pleura to the thoracic wall)
Visceral pleura
covers the lungs. Attaches directly to the lungs. Appears shiny & moist over the surface of lungs. Continuous with parietal pleura at the hilum of the lung.
Synchondrosis
immovable cartilaginous joint
Lumbar ribs
in <1% of population, can be me missed diagnosed as a fracture of the L1 transvers process, no usually associated with any clinical condition.
Cervical ribs
in about 0.5 - 2% of the population, associated with Thoracic Outlet Syndrome, can compress neurovascular structures exiting superior thoracic aperture
Scapular line
intercepts the inferior angle of scapular
Parietal pleura
lines thoracic wall including the diaphragm.
Function of Pleura
lubricates the pleural surfaces , provides surface tension that keeps the lung surface in contact with the chest wall. This helps the lungs to adhere to the thoracic wall, separates the lungs from each other in air tight cavities.
Chylothorax
lymph into the pleural cavity
Mediastinum
median septum within the thoracic cavity (between lungs)
Midclavicular line
midpoint of clavicle
Parasternal line
midway between lateral sternum and the midclavicular line
Costal angle
most rib fractures occur immediately to the anterior of the _____ _____, which is the weakest part of the rib
Coarctation
narrowing of part of the aorta
Chondral
pertaining to the cartilage
Costal
pleura covers the internal surfaces of the thoracic wall.
Diaphragmatic
pleura covers the superior thoracic part of the Diaphragm.
Posterior axillary line
posterior axillary fold (formed by l.dorsi and t.major as span back from humerus)
Pleural cavity
potential space between the two pleura, contains pleural fluid.
Pleurodesis
procedure causing parietal & visceral pleura to stick together
Thoracentensis
puncturing the thoracic wall with a needle
Costomediastinal
recesses located posteriorly to the sternum. Left recess markedly larger than on the right side because of the cardiac notch.
Costodiaphragmatic
recesses located superiorly to the diaphragmatic dome. More pronounced from 8th to 10th ribs. Contains only pleural fluids. (ideal site for thoracentesis)
Active Expiration
recoil of lungs using internal intercostals, innermost intercostal, and abdomen
Dyspnea
shortness of breath
External intercostal muscles
span from the rib tubercles to the costochondral junction. Muscle fibers run inferoanteriorly from rib above to the rib below ("hands in pocket" orientation)
Pleurectomy
surgical incision of the pleura
Thoracotomy
surgical opening of the thorax
Pneumonectomy
surgical removal of the lung
Sibson's fascia
thickened endothoracic fascia above the 1st rib to C7 transverse process (covers the apex of lung, which is prone to injuries)
Pleura
thin mesothelial serous membranes that encloses the lungs and the parietal wall.
Pectus carinatum
• Protrusion of the sternum and costal cartilages. Causes: • Connective tissue disorders. Complications: • Scoliosis and congenital heart disease.