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.