Thorax Flashcards
Superior thoracic aperture
Boundaries - Posterior: T1, Lateral: 1st pair of ribs, Anterior: superior border of mandible
Structures running through: trachea, esophagus, phrenic and vagus nerves enter, great vessels exit
Inferior thoracic aperture
Boundaries - posterior: T12, lateral: post. - ribs 11 + 12, ant. - ribs 7-10, anterior: xiphisternal joint between xiphoid process and sternum.
Diaphragm takes origin here.
Mediastinum
Space between spine, sternum, manubrium, and xiphoid process. Where heart rests along with esophagus and great vessels. Has sections.
Which are the true ribs, and what type of articulation do they have?
1-7, vertebrocostal
Which are the atypical ribs?
1,2,11, and 12
Which are the false ribs, and what type of articulation do they have?
8-10, vertebrochondral
Which are the floating ribs
11 + 12
What are the unique aspects of the first rib?
Grooves for subclavian vein + artery, Scalene tubercle and ridge, and only one facet on head
What are the unique aspects of the second rib?
Tuberosity for serratus anterior
What runs through the costal groove?
Intercostal arteries, veins, and nerves
Intervertebral Joint
Type: symphysis (secondary cartilaginous joint)
Articulation: adjacent vertebral bodies bound together by intervertebral discs
Ligaments: anterior and posterior longitudinal
Costovertebral joints of head of ribs (1)
Type: synovial plane of joint
Articulation: head of each rib with superior demarcate of corresponding vertebral body and inferior demarcate or costal facet of vertebral body superior to it
Ligaments: radiate and intra-articular ligaments of head of rib
Costotransverse joint (2)
Type: synovial plane of joint
Articulation: Articulation of tubercle of rib with transverse process of corresponding vertebra
Ligaments: Lateral and superior costotransverse
1st sternocostal joint (3)
Type: primary cartilaginous joint
Articulation: articulation of 1st costal cartilages with manubrium of sternum
Ligaments: anterior and posterior radiate sternocostal
2nd - 7th strenocostal joints (4)
Type: synovial plane joints
Articulation: articulation of 2nd-7th pair of costal cartilages with sternum
Ligaments: anterior and posterior radiate sternocostal
Sternoclavicular joint (5)
Type: saddle type of synovial joint
Articulation: sternal end of clavicle with manubrium and 1st costal cartilage
Ligaments: anterior and posterior sternoclavicular ligaments; costoclavicular ligament
Costochondral joint (6)
Type: primary cartilaginous joint
Articulation: articulation of lateral end of costal cartilage with sternal end of rib
Ligament: cartilage and bone; bound together by periosteum
Interchondral joint (7)
Type: synovial plane joint
Articulation: articulation between costal cartilages of 6th-7th, 7th-8th, and 8th-9th ribs
Ligaments: interchondral ligaments
Manubriosternal joint
Type: secondary cartilaginous joint (symphysis)
Articulation: articulation between manubrium and body of sternum
Xiphisternal joint
Type: primary cartilaginous joint (synchondrosis)
Articulation: articulation between xiphoid process and body of sternum
What are the innervations to the diaphragm?
Phrenic nerve and musculophrenic arteries
External intercostal muscle
Superior attachment: inferior border of ribs
Inferior attachment: superior border of ribs below
Innervation: Intercostal nerve
Action: elevates ribs during inspiration during forced inspiration
Internal intercostal muscle and innermost intercostal muscle
Superior attachment: inferior border of ribs
Inferior attachment: superior border of ribs below
Innervation: Intercostal nerve
Action: during forced inspiration interosseous part depresses ribs, interchondral part elevates ribs
Transversus thoracis
Superior attachment: posterior surface of lower sternum
Inferior attachment: internal surface of costal cartilage 2-6
Action: weakly depresses ribs
Subcostal muscle
Superior attachment: internal surface of lower ribs near their angle
Inferior attachment: superior borders of 2nd or 3rd ribs below
Action: during forced inspiration interosseous part depresses ribs, interchondral part elevates ribs
Levatores costarum muscle
Superior attachment: transverse process of T7-11
Inferior attachment: subjacent ribs between tubercle and angle
Innervation: posterior rami of C8-T11
Action: elevates ribs
Serratus posterior superior muscle
Superior attachment: nuchal ligament, spinous process of C7-T3 vertebrae
Inferior attachment: superior border of ribs 2-4
Innervation: 2nd-5th intercostal nerves
Action: elevates ribs
Serratus posterior inferior muscles
Superior attachment: spinous process of T11-L2 vertebrae
Inferior attachment: inferior border of ribs 8-12 near their angle
Innervation: 9th-11th intercostal nerves, subcostal (T12) nerve
Action: depress ribs
Posterior intercostal artery origin
thoracic aorta
Anterior intercostal arteries origins
internal thoracic arteries and musculophrenic arteries
Unique aspects of right pleura
Horizontal fissure between superior and middle lobe
Uniques aspects of left pleura
Cardiac notch in superior lobe and lingula at apex of superior lobe. Where the heart sits.
Order of bronchial tree from top of right pleura to bottom
Right main bronchus, right superior lobar (“eparterial”) bronchus, right middle lobar bronchus, segmental bronchus, right lower lobe bronchus
Order of bronchial tree from top of left pleura to bottom
Left main bronchus, left superior lobar bronchus, left inferior lobar bronchus
Origins of left vs. right bronchial arteries
Left: aorta
Right: intercostal arteries, aorta, and left bronchial artery
Bronchial vein drainage left vs. right
Left: accessory hemiazygous vein or intercostal vein
Right: azygous vein
Pulmonary Collapse
Air infiltrating pleural cavity (pneumothorax) can break surface tension between visceral and parietal pleura. When this happens, the elastic lung tissue will recoil (collapse) leaving air filled space within the pleural cavity that prevents expansion of the lung during inspiration.
Hemothorax, Hydrothorax, and Chylothorax
Infiltration of pleural cavity via different substances causes lung collapse.
Hemo - blood
Hydro - fluid
Lymph - chylo
Pleuritis/pleurisy
Inflammation of pleura, may cause “scraping sounds” during auscultation, and can cause sharp stabbing pain.
Pulmonary embolism (PE)
Obstruction of pulmonary artery by blood clot, fat globule, or air bubble; often fatal.
Passes form vein into right side of heart via vena cava and then travels through heart an into pulmonary artery, obstructing blood flow.
Deep vein thrombosis (DVT) is a common cause.
Bronchogenic carcinoma
Common type of lung cancer arising from bronchial epithelium.
Smoking is a major cause.
Highly metastatic due to association of lymphatics in bronchial tissue.
Typically metastasizes to brain and cranium.
Malignant Mesothelioma
Rarer type of lung cancer affecting pleura (mesothelium)
Caused by exposure to asbestos.
Can affect other internal organs.
Pulmonary tuberculosis
Bacterial infection of the lungs (mycobacterium tuberculosis).
Can spread to other organs.
Contagion spread through air through droplets from an infected individual coughing, sneezing, or talking.
1/3 of the world’s population is currently infected with TB, but only 5-10% become sick or infection (active TB).
