Thorax Wall Flashcards
true ribs
1-7, attached to sternum
false ribs
8-12, costal cartilages of 8-10 articulate with the superior cartilage
what does the sternal edge of the 10th rib attach to?
costal cartilage of 9th rib
floating ribs
11-12, no anterior connections to other ribs or sternum
label rib
sternum
where does the head of the rib articulate?
demifacets of the superior costal facet and inferior costal facet of 2 adjacent vertebrae
where does the tubercle of the rib articulate
transverse process of the corresponding vertebra
what type of joint is formed at the head of rib and vertebra?
synovial joint
what is unique about the jointof the head of rib and superior and inferior costal facet
it is a synovial joint divided into 2 compartments by intrarticular ligament
ligament between the neck of rib and transverse process?
costotransverse ligament
ligament lateral to the joint and runs between the transverse process and tubercle of rib
lateral costotransverse ligament
external intercostal muscle location
between ribs, extends from tubercles of rib to the costal cartilages
function of external intercostal muscles
elevate ribs, most active in inspiration
internal intercostal location
deep to external intercostals, muscle fibers extend from sternum to the angle of the ribs
where is the internal intercostal membrane?
extends posteriorly toward vertebral column
external intercostal membrane location
extending from costal cartilage to the sternum
internal intercostal function
depress ribs, most active in expiration
innermost intercostal muscle function and location
depress ribs, most evident in lateral throracic wall, fibers running in dame direction of internal intercostals
transverse thoracic muscle location
originate from posterior part of xiphoid process, inferior aspect of body of sternum and adjacent costal cartilages; fibers run superolaterally to insert onto the lower borders of ribs 2-6
function of transverse thoracic muscle
depress ribs
where are vessels and nerves that supply intercostals?
just inferior to the inferior border of the rib, between internal intercostal and innermost intercostals; VAN - intercostal vein, intercostal artery, intercostal nerve
significance of location of the intercostal nerves, arteries and veins
when giving a nerve block, needle to be inserted just inferior to the inferior rib border to find the nerve
function of the internal intercostal interchondral part
elevation of the ribs at the chostrochondral joint, increases anteroposterior dimension
meaning of “pump handle” movement of ribs
in the upper/anteiror ribs, ribs are elevated, and sternum moves upward and forward, increasing anteroposterior dimension of the thorax
meaning of “bucket handle movement” of ribs
in lateral and lower ribs, ribs are elevated and the shafts of the ribs move laterally, increasing the transverse dimension of the thorax
what occurs during passive expiration
diaphragm, intercostals relax, decreases intrathoracic volume and increases intrathoracic pressure, intra-abdominal pressure decreases, and abdominal viscera are decompressed, allowing stretched elastic tissue of lungs to recoil and expel air
what gives rise to the anterior intercostal arteries of the upper 6 intercostals?
the subclavian arteries give off the internal thoracic arteries, which give rise to the anterior intercostal arteries of the upper 6 intercostals
what occurs at the 6th intercostal space?
the internal thoracic arteries terminate by dividing into the superior epigastric and musculophrenic arteries
where do the lower 6 anterior intercostal arteries arise from?
the musculophrenic arteries (that split from the internal thoracic)
where do the posterior intercostal arteries originate from?
the thoracic aorta - except the first 2 posterior intercostal arteries taht arise from the supreme intercostal artery (branch of the costocervical trunk)
where do the 1st 2 posterior intercostal arteries arise from?
supreme intercostal artery that is a branch from the costocervical trunk
significance of the sternal angle?
- the 2nd rib attaches there
- the division of the superior and inferior mediastinum
- the trachea bifurcates
where do posterior intercostal veins drain?
into the azygos vein, which drains into the superior vena cava
where do the anterior intercostal veins drain
into the musculophrenic or internal thoracic veins
where do the intercostal nerves branch off?
ventral rami of T1-T11 spinal nerves
what is the subcostal nerve?
ventral ramus of the T12 spinal nerve, lies inferior to 12th rub
what branches off the intercostal nerves?
the lateral cutaneous branch, and the anterior cutaneous branch
what is significant about the lateral cutaneous branch of T2?
the lateral cutaneous branch of T2 joints the medial brachial cutaneous nerve to supply the medial side of the arm, this is why cardiac pain is referred to the medial side of the left arm
what makes up the superior thoracic aperture and what does it contain?(thoracic inlet)
T1 vertebra, rib 1 and manubrium of sternum; contains superior aspects of the pleural cavities and mediastinum
what makes up the inferior thoracic aperture?
T12 vertebra, rib 12, distal “ends” of lower ribs, xiphoid process, closed by diaphragm
what goes into the superior thoracic aperture?
trachea, esophagus, brachiocephalic vein, phrenic nerve and vagus nerve
what comes out of the superior thoracic aperture
brachiocephalic artery, left common carotid artery, left subclavian artery, thoracic duct, sympathetic trunks
what comes into the inferior thoracic aperture?
inferior vena cava
what comes out of the inferior thoracic aperture?
descending aorta, esophagus
what is the primary muscle of inspiration
diaphragm
what does the diaphragm attach to
xiphoid process, ribs, lumbar vertebrae
innervation diaphragm (C3,C4,C5)
phrenic nerve
blood supply diaphragm
superior and inferior phrenic arteries just off the aorta
what structures travel between the thorax and abdomen that pass through the diaphragm?
aorta, inferior vena cava, esophagus, vagus nerve, thoracic duct, azygos/hemiazygos vein
what surrounds the lungs?
parietal pleura lining the thoracic cavity, visceral pleura in direct contact with lung
divisions of the parietal pleura
cervical pleura, costal pleura, diaphragmatic pleura, mediastinal pleura
what surrounds the parietal pleura?
endothoracic pleura - holds parietal pleura to thorax wall
where is the cervical pleura?
covers the apex of the lung, extends into the thoracic inlet, superior to 1st rib, cupola (dome over apex)
what innervates the parietal pleura?
somatic afferent fibers
what specifically innervates the costal pleura
intercostal nerves - can pinpoint specific, localized pain (pleurisy)
what innervates diaphragmatic and mediastinal pleura?
phrenic nerves, causes referred, dull, not well localized pain in the C3-C5 dermatomes (lateral neck and supraclavicular regions)
what is the costodiaphragmatic and costomediastinal recesses?
extensions of pleural cavities that are devoid of lung tissue, and are potential spaces where fluid can collect
how far does the pleura extend?
at midclavicular line: rib 8
at midaxillary line: rib 10
posteriorly: T12
inferior margin of the lung (quiet respiration)?
midclavicular line: rib 6
midaxillary line: rib 8
posteriorly: T10
where to insert needle for thoracentesis?
inferior to rib 8 in the 9th intercostal space, so the lung is not punctured. insert the needle tip superiorly to reduce the risk of puncturing the liver
what is the root of the lung?
“forearm of the fist that is the lung”
structures that attach the lung to structures in the mediastinum like pulmonary artery, veins, bronchus
what is the hilum of lung
entry and exit point of the root structures
what structures are in the root/hilum of the lung?
pulmonary artery (superior), pulmonary veins (inferior), primary bronchus
what is the pulmonary ligament
transition of parietal to visceral pleura, extends inferiorly from lung root
lobes and fissures of the right lung
3 lobes, superior, inferior, middle; 2 fissures, horizontal and oblique
lobes and fissures of left lung
2 lobes, superior and inferior, 1 oblique fissure
what is an azygos lobe
a laterally displaced azygos vein makes a deep fissure into the apical segment of the right upper lobe during embryological development
what is a pancoast tumor?
tumor involving apex of lung, may involve recurrent laryngeal nerve, inferior portion of brachial plexus (C8, T1), sympathetic trunks, subclavian blood vessels
impressions on medial surface of right lung
heart, superior and inferior vena cava, azygos vein, esophagus
impressions on medial surface of left lung
heart, aortic arch, descending aorta, esophagus
where does the trachea divide into primary bronchi?
sternal angle
explain the divisions of the trachea
trachea divides into the primary bronchi at the sternal angle, primary bronchi enter the hilum and divide into secondary/lobar bronchi (3 right lung, 2 left lung), lobar bronchi divide into tertiary (segmental), then alevoli
clinical significance of the right primary bronchus
right primary bronchus is shorter, wider, more vertically oriented than left, so foreign objects more likely to enter this side
where does the larynx transition to the trachea?
at C6
what is the carina?
the last cartilaginous ring of the trachea that makes a “keel” cartilage at the tracheal bifurcation
what do the pulmonary arteries carry?
deoxygenated blood from the right ventricle to the lungs
what do the pulmonary veins carry?
oxygenated blood from the lungs to the left atrium
what is a bronchopulmonary segment
area of lung supplied by a tertiary bronchus and its accompanying pulmonary artery branch (8-10 of these in each lung)
flow of lymph in the lungs?
lymphatic vessels initially drain into pulmonary lymph nodes around the lobar bronchi, then drain into the bronchopulmonary lymph nodes in the hilum, then drain into the superior and inferior tracheobronchial lymph nodes that are superior and inferior to the bifurcation of the trachea and primary bronchi, then flows to the right and left bronchomediastinal lymph trunks
what is asthma
variable obstruction of the airway caused by spasmodic contraction of the smooth muscle in the bronchial tree
what is bronchitis
inflammation of mucous membranes of the bronchial tree
what is emphysema
destruction of the walls of the airspaces distal to the terminal bronchioles, reducing surface are for gas exhange
what is COPD
includes chronic bronchitis and emphysema
what is pleurisy
inflammation of the pleura, pain sensed by intercostal nerves
what is pneumothorax
air in the pleural cavity that results in partial or total collapse of the lung
causes of pneumothorax
parietal pleura penetrated by external trauma or visceral pleura interrupted by ruptured pulmonary cysts
mechanism of pneumothorax
pleura punctured, air enters pleural cavity and lung on same side as injury collapses due to its own surface tension and recoil of elastic fibers
