Module 4: Thoracic Wall and Mediastinum Flashcards
What are the boundaries of the thoracic cavity?
posterior: spine
anterior: sternum
inferior: diaphragm
superior: superior thoracic aperture
What are the contents of the thoracic cavity?
respiratory and cardiovascular organs
What are the compartments of the thoracic cavity?
pleural cavity: Right and Left
Mediastinum: superior and inferior (midline)
What are the components of the thoracic wall?
-skin
-subcutaneous tissue
-ribs
-intercostal muscles
What is the function of the thoracic wall?
- protection
- respiration
- muscle attachment
What are the 3 different types of ribs?
True: 1st-7th
- direct cartilaginous attachment to sternum
False: 8th-10th
- indirect connection (come together to connect to sternum)
Floating: 11th and 12th
- do not attach to sternum
What is the general structure of a rib?
head
neck
costal tubercle
costal angle(posterior)
body/shaft
What are the 3 rib joints and their synovial classification?
costovertebral: head»_space; vertebral body
costotranverse: costal tubercle»_space; transverse process
sternocostal: sternum»_space; costal cartilage
plane/gliding
What are the unique landmarks of the 1st rib?
scalene tubercle
groove for subclavian artery
groove for subclavian vein
What is the position of the anterior scalene muscle relative to the subclavian artery?
anterior to subclavian artery
What are the unique landmarks of the sternum?
manubrium
- jugular and clavicular notch/facet
body
- sternal angle (joint between manubrium and body)
- costal notches/facets
xiphoid process
Where does the 2nd rib attach to the sternum?
sternal angle
What are the muscles of the thoracic wall?
external intercostal
internal intercostal
innermost intercostal
tranversus thoracis
diaphragm
What are the OIAN for the external intercostal?
O: rib superior-lateral
I: rib inferior medial
A: elevation of ribs
N: intercostal nerve (segmental)
start from spine, do not reach sternum
What are the OIANs of the internal and innermost intercostal muscles?
O: rib superior-medial
I: rib inferior-lateral
A: depression of ribs
N: intercostal nerve (segmental)
start from sternum, do not reach spine
What are the OIANs of the tranversus thoracis muscle?
O: posterior sternum
I: costal cartilages
A: depress ribs
N: intercostal nerves (segmental)
What are the OIANs of the diaphragm?
O: xiphoid process, inner surface of lower ribs, costal cartilages, lumbar vertebrae via crura
I: central tendon
A: inspiration(negative pressure)
N: phrenic nerve c3-5 (R+L)
What are the actions of the sternum and ribs during expiration?
sternum: move downward and back
ribs: depress and move middle of shaft medially (bucket handle)
What are the actions of the ribs and sternum during inspiration?
sternum: moves upward and forward (pump handle)
ribs: elevate and move middle of shaft laterally
What is the naming convention of intercostal nerves?
T1-6: upper intercostal
T7-11: lower intercostal
T12: subcostal
What are the major landmarks of the innervation of the thoracic wall?
T4: nipple line
T6: skin over xiphoid
T10: umbilicus
What branches of arteries come off of the descending aorta?
bronchials
esophageal
posterior intercostals (3-11)
subcostal (12)
What arteries branch off th internal thoracic artery?
pericardiophrenic a.
anterior intercostals (1-6)
superior epigastric
musculophrenic
What artery do the anterior intercostal arteries (7-9) branch off of?
musculophrenic artery
What is the function of cisterna chyli?
forms below diaphragm and provides origin to thoracic duct
What is function of the thoracic duct?
drains nodes of the right and left lower extremities, pelvis, abdomen left thorax, left upper extremity, left head, and left neck
What is the function of the right lymphatic duct?
drain nodes of the right thorax, right upper extremity, and right head & neck
forms union of right jugular, right subclavian, and right bronchomediastinal trunks
What nodes drain into the right and left broncomediastinal trunks?
parasternal, visceral, and diaphragmatic nodes
What nodes are parietal?
parasternal
intercostal
posterior mediastinal
diaphragmatic
What is the function of parasternal lymph nodes?
drain breast, abdominal wall, pleura, and liver
What is the function of intercostal lymph nodes?
drain lateral and posterior thoracic wall
What is the function of posterior mediastinal lymph nodes?
drain pleura and esophagus
What is the function of diaphragmatic lymph nodes?
drain liver, pleura, and diaphragm
What are the 4 visceral lymph nodes?
pulmonary
bronchopulmonary
tracheobrocnial
paratracheal
What is the function of pulmonary lymph nodes?
drain lung
What is the function of bronchopulmonary lymph nodes?
drain bronchi
What is the function of tracheobronchial lymph nodes?
drain trachea & heart
What is the function of paratracheal lymph nodes?
drain tracheobronchial nodes
What are the 5 breast lymph nodes?
parasternal
inguinal
infraclavicular
axillary
apical axillary
What is the function of parasternal lymph?
drain medial breast bilaterally
What is the function of inguinal lymph?
may drain inferior breast
What is the function of infraclavicular lymph?
may drain superior breast
What is the function of axillary lymph?
predominant drainage of the breast
Where does the neurovascular structure of the intercostal muscles run?
between the inner and innermost intercostal muscles.
What is the orientation of intercostal neurovasculature?
vein
artery
nerve
What are the external features of the right lung?
- apex
- 3 lobes (superior, middle, inferior)
- horizontal fissure
- oblique fissure
What are the external features of the left lung?
- apex
- 2 lobes (superior and inferior)
- oblique fissure
- lingula
What pattern of branching of the bronchial tree?
trachea > primary bronchi > secondary (lobar) bronchi > tertiary (segmental) bronchi
What is the point of bifurcation of the trachea?
carina
What is different about the right bronchus compared to the left bronchus?
more vertical and larger
(easier for objects to go down this bronchus)
How many bronchopulmonary segments are there?
10 segments
What structures comprise the root of the lung?
- pulmonary artery
- pulmonary vein
- bronchi
What pleural covering covers the root of the lung and what is its purpose?
- pulmonary ligament
- allows expansion of blood vessels
What structure does the root of the lung pass through?
the hilum
What is the difference between the structures in the root of the right lung and the root of the left lung?
Right: pulmonary artery is anterior to bronchus
Left: pulmonary artery is superior to bronchus
R.A.L.S.: Right lobe-anterior, Left lobe- superior
What vessels supply the lungs?
bronchial branches from the descending aorta
What are the two pleural coverings of the lungs?
parietal pleura (outer) and visceral pleura (inner)
What are the regions of the parietal pleura?
- cervical: neck
- costal: largest
- diaphragmatic: over diaphragm
- mediastinal: medial
What are the reflections of the parental pleura?
costodiaphragmatic
costovertebral
costomediastinal
What are the recesses of the parietal pleura and their significance?
- costodiaphragmatic = costal > diaphragmatic region
- costomediastinal = costal > mediastinal region
- site of fluid accumulation
What is the significance of pulmonary collapse?
- puncture of parietal pleura
- air enters between pleura, descreasing surface tension causing clinging and collapsed lung
- can be trauma from dry needling
- pneumothorax
What is the order of pericardium, superficial to deep?
fibrous pericardium > parietal pericardium > visceral pericardium (epicardium) > myocardium > endocardium
What pericardium layers are part of the serous pericardium?
parietal pericardium and visceral pericardium (epicardium)
What pericardium layers are part of the heart?
epicardium (visceral pericardium)
myocardium
endocardium: single layer of cells
What are the surface features of the heart?
- R auricle
- R coronary sulcus
- L auricle
- anterior interventricular sulcus
- apex
Not pictured:
- L coronary sulcus
- posterior interventricular sulcus
What are the internal features of the right atrium?
- crista terminalis: smooth ridge
- interatrial septum
- fossa ovalis
- pectinate muscle
- opening of the:
- coronary sinus
- IVC and SVC
- atrioventricular valve
What are the internal features of the left atrium?
- valve of foramen ovale
- opening of the:
- L atrioventricular valve
- pulmonary veins
What are the internal features of the left ventricle?
- opening of the:
- aortic valve
- L atrioventricular valve
- chordae tendinae
- papillary muscle (2)
- onterventricular septum
- trabeculae carneae
What are the internal features of the right ventricle?
- opening of the:
*pulmonary trunk - R atrioventricular valve
- chordae tendineae
- papillary muscle (3)
- conus arteriosus
- septomarginal trabecula (moderator band)
- trabeculae carneae
How many papillary muscles are in the R Ventricle?
3
- anterior
- posterior
- septal
How many papillary muscles are in the L Ventricle?
2
- anterior
- posterior
Which ventricle is thicker?
L ventricle because it shunts blood to entire body
How many pulmonary veins are there?
4
What is the difference between the Right and Left AV valves?
Right = tricuspid
Left = bicuspid (mitral)
Which chamber of the heart does the pulmonary trunk connect to?
right ventricle
What chamber of the heart does the aortic valve connect to?
left ventricle
Where do the coronary arteries originate in the heart?
ascending aorta
What is the role of the chordae tendineae and what do they attach to?
- anchor valve flaps from allowing blood reflux from the R and L ventricles into the R and L atrium
- papillary muscle
How many secondary bronchi are in the L and R lung?
L: 2 = superior and inferior
R: 3 = superior, middle, & inferior
What are the cardiac auscultation sites?
Aortic
- upper right, 2nd intercostal space
Pulmonary
- upper left, 2nd intercostal space
R AV valve
- medial right, 5th intercostal space
L AV valve
- lower left, 5th intercostal space
What structures branch off the R coronary artery?
- right marginal artery
- posterior interventricular artery (anastomosis with anterior)
What structures branch off the L coronary artery?
- anterior interventricular artery
- circumflex artery
- L marginal artery
Does the heart have collateral circulation supplying it?
no, the anastomoses are not great enough to do so
Describe the blood flow through the heart including chambers and valves.
SVC + IVC > R Atrium > tricuspid valve > R ventricle > pulmonary valve > Pulmonary trunk/artery > lung > pulmonary veins > L atrium > bicuspid valve > L Ventricle > aortic valve > ascending aorta
What is the conduction system of the heart?
Sinoatrial Node (RA) > atrioventricular node (R AV Valve) > atrioventricular bundle > L + R bundle branches
What is the role of the moderator band?
gives right bundle branch rapid access to the lateral wall of the R ventricle
What is referred pain during cardiac arrest?
pain receptors in the myocardium relay stimuli through visceral afferent axons that share somatic axons with the skin, the brain then interprets the pain coming from the skin
What are the sites of referred pain?
L pectoral region
L shoulder
L Medial Upper Extremity to pinky
What is the location of fossa ovalis and its previous function?
- interatrial septum
- fetal remnant of foremen ovale
- connected right and left atrium for blood flow
What is the location of the ligamentum arteriosum?
- fetal remnant of ductus arteriosus
- connected arch of aorta to pulmonary trunk
What are the veins of the coronary sinus and their locations?
- great cardiac: ant IV sulcus
- oblique vein of left atrium: superior of coronary sinus
- posterior vein of the left ventricle
- middle cardiac: post IV sulcus
- small cardiac: R coronary sulcus
What is the role of white rami communicans?
T1-L2
- carry preganglionic sympathetic axons to the sympathetic chain and abdominal ganglia and sensory axons from the visceral spinal cord
What is the role of gray rami communicans?
carry postganglionic sympathetic axons from the sympathetic chain to spinal nerves for distribution through the dorsal and ventral rami, and sensory axons from the viscera to the spinal cord
What is the role of the phrenic nerve?
C3-5
- sensory and postganglionic sympathetic innervation to the pericardium and central tendon; motor and postganglionic sympathetic innervation to the diaphragm
What is the role of the vagus nerve?
wandering
- carries preganglionic parasympathetic axons innervating thoracic and abdominal viscera to the level of the left colic flex and visceral sensory axons innervating the same
What is the relation between rami communicans, sympathetic chain, and intercostal nerves?
ventral rami (intercostal nerves) > white rami > symp chain > grey rami > intercostal nerve
What structures does the thoracic duct lie between?
Azygos vein and esophagus
Duck between 2 goose
What structures does the thoracic duct lie between?
Azygos vein and esophagus
Duck between 2 goose
What is the sequence of the great vessels of the heart?
Anterior to posterior:
Pulmonary trunk > Ascending aorta > sup vena cava
What is the role of the septomarginal trabecula?
Moderator band; holds nervous cell tissue allows for jumping off the right bundle branch to the lateral side of the right ventricle
What area of the heart does the great cardiac vein drain?
Drains blood from left side of heart, located in Ant IV Sulcus
What is the role of the coronary sinus?
Veins empty here then to the right atrium
What is the role of the middle cardiac vein and its location
Drains blood from posterior side of heart, located in Post IV Sulcus
What part of the heart does the right coronary artery supply?
- right atrium
- most of right ventricle
- part of left ventricle
- part of IV septum
- SA node
- AV node
What part of the heart does the left coronary artery supply?
- left atrium
- most of the left ventricle
- part of the right ventricle
- most of the IV Septum
- SA node
- AV node
What is the reason for referred pain?
Phrenic nerve is C3-5, when heart pain occcurs, it shares sensory skin cells of C3-5 dermatome, making the left shoulder, left pectoralis, and left arm hurt
What is the conducting system of the heart?
Action potential generated in SA node, right atrial walls to the AV node. potential goes through AV node to bundle branches to purkinje fibers to ventricular walls
What is sympathetic innovation of the heart?
Sympathetic chain
What is the parasympathetic innovation of the heart?
Valgus nerve
What arteries anastomos in the heart?
Right coronary and circumflex of LC
Post IV Art and Ant IV Art
What is the relation of the rami communicans to the sympathetic chain ganglia and intercostal nerves including the type of axon found within?
sympathetic pre-ganglionic branch leaves the lateral horn of the spinal cord > travels along ventral root through mixed spinal nerve > goes into white rami communican in the sympathetic chain ganglion > synapses with post-ganglionic branch axons > leaves through grey rami communicans > travels through ventral ramus to corresponding intercostal space for sympathetic innervation
