Organization of thorax Flashcards
Superior and inferior borders of thorax
root of neck and thoracic diaphragm
what makes up the thorax. generally
osteocartilaginous components, muscles, fascia, skin and thoracic cavity(pulmonary and mediastinum)
function of thorax
protection of underlying viscera, respiration and muscle attachment
Which ribs have a full facet for rib
1,10,11,12
Which ribs are true ribs
1-7
which ribs are “false ribs”
8-10
which ribs are “floating ribs
11-12
what does the head of the rib articulate with
adjacent vertebral body
what does the tubercle on the rib articulate with
the transverse process
what runs in costal groove
intercostal vein artery and nerve
what provides the increased elasticity for thoracic wall
costal cartilage
What is unique anatomically of first rib
broad, horizontal shaft with pronounced curvature
head has a single facet for articulation TV1
shaft has groove to subclavian a and vein, scalene tubercle
where is the transverse thoracic plane
sternal angle to disk between L4 and L5
what is unique anatomically of second rib
serratus anterior tuberosity on superior surface
what is unique anatomically of 10th rib
single articular facet on head for articulation with body of TV10
what is unique anatomically of 11th and 12th ribs
single articular facet on head, absence of neck/tubercle
where do rib fractures occur most often
near the angle, middle ribs
what is a flail chest
multiple ribs broken in 2 or more places.
what disk is the suprasternal(jugular notch) in front of
TV2/TV3
what ribs articulate with manubrium
1 and 2
what ribs articulate with sternum
2-7
what do the lateral demi facets of the xiphoid process articulate with
costal cartilage of 7th rib
what does the sternal angle demarcate
articulation of 2nd rib
What is pectus excavatum
anterior thoracic wall is sunken in and carinatum protrusion- congenital anomalies from malformation of sternum and ribs
what are the boundaries of the superior thoracic aperture
anterior- jugular notch
lateral- 1st rib
posterior- 1st thoracic vertebra
injury or surgery within the superior thoracic aperture may have what consequence
pneuomothorax because the pleural space extends superiorly into neck region
what are the boundaries of the inferior thoracic aperture
anterior- xiphisternal joint
lateral- costal margin
posterior- 12th thoracic vertebra and 11th and 12th rib
injury or surgery within the inferior thoracic aperture may have what consequence
pnuemothorax because plueral space extends inferiorly to inferior aperture
what is radiate ligament
vertebral body to the head
superior costotransverse ligaments
rib to transverse process on vertebra above
lateral costotransverse ligaments
between transverse process and rib of same level
how many pairs are there of articulations of costal cartilages and sternum
7
describe joint of 1st sternocostal joint
synchondrosis, no movement
what types of joints are sternocostal 2-7
synovial plane
describe the articulation between the rib and costal cartilage
synchondrosis, very little movement
what are the interchonral articulations and where are they found
8th-10th
between costal cartilages of ribs 8-10 with costa cartilage above
what ligaments support joint capsule of ribs
anterior and posterior radiate ligaments
what are the three layers of mm in the thoracic cavity
external intercostals, internal intercostals and innermost intercostals
which way to the external intercostal m fibers go
infero-medially
which way to the internal intercostal m fibers go
inferio-laterally
what make sup the innermost intercostals
discontinuous sheet of muscle.
3 components that make up innermost intercostals
transverse thoracis (anteriorly) innermost intercostal (laterally) subcostalis (posteriorly)
where does the neurovascular bundle run between ribs
between the internal intercostal and innermost intercostal mm
what is the endothoracic fascia
CT lining entire surface of internal thoracic wall and superior surface of diaphragm
also adheres to parietal pleura
Why is the endothoracic fascia important for surgeries requiring access to thoracic cavity
cleavage plane between thoracic wall and pleura
which joint of thoracic cavity allows for elevation and depression of the most distal portio of ribs (anterior)
costotransverse joint
what is the importance of 1st rib in respiration
fixed joint, so moves entire sternum thus moving all the ribs
Describe what allows for the increase in transverse diameter of thoracic wall
gliding of costovertebral and costotransverse joints
what allows for considerable increase in anterior posterior cavity during respiration
the inferior slope of the distal portions of ribs
What allows the increase in vertical diameter during respiration
diphragm inn by phrenic C3 C4 C5
During expiration the superior portion of diaphragm extends to what intercostal space
4th intercostal space
What are the thoracic wall mm involved in inspiration
serratus posterior superior and inferior
leavator costorum
external intercostal mm
what are the thoracic mm involved in expiration
internal intercostal mm
transverse thoracic mm
what other mm are involved in forced inspiration
sternocleidomastoid scalene mm serratus anterior pectoralis minor and major quadratus lumborum
mm involved during forced expiration
anterolateral abdominal wall mm
what innervates thoracic wall
intercostal 11 pair and subcostal 1 pair
what type of information do the intercostal nn and subcostal n contain
preganglionic sympathetic nerve cell processes from spinal cord to sympathetic chain via 14 pair white rami communicantes
postganglionic sypathetic nerve cell proccesses via 31 pair gray rami communicantes
Where do the intercostal nn course
within endothoracic fascia
near rib angle, nerves pass between 2nd and 3rd m layers
What are the other branches of intercostal nn besides the rami communicantes
muscular branches, collateral branch, lateral perforating cutaneous branch
anterior perforating cutaneous branch
Where is the collateral branch of intercostal nn
near angle of rib, course superior border of rib
Describe the ventral ramus of T1
larger superior trunk which goes to brachial plexus and small inferior trunk– 1st intercostal n (no cutaneous to thoracic wall)
describe the lateral cutaneous branch of intercostal nerve 2 and soemtimes 3
intercostobrachial cutaneous n supplying skin and subcu tissue of axilla and medial brachial area
Describe the intercostal nn 7-11 and subcostal
continue anterolaterally as thoracoabdominal nn because inn abdominal wall as well
problem at TV10
look for problem at 10th thoracic n
describe dermatome for nipple level in males
T4
what dermatome is the xiphoid
T6
what is the dermatome for umbilicus
T10
How many anterior intercostal aa are there
9 pair
Where do the anterior intercostal aa originate from
the internal thoracic artery
what does the internal thoracic a branch from
the subclavian a
what are the terminal branches of the internal thoracic a
musculophrenic and superior epigastric aa
Where does the musculophrenic a course
follow costal arch and provides anterior intercostal aa to spaces below 6th
how many anteiror intercostal aa supply each space
2 usually
how many posterior intercostal aa are there
11 pair and 1 subcostal pair
where do the posterior intercostal aa arise from
thoracic, descending aorta 3-11 and subcostal a
costocervical trunk provides highest intercostal a to posterior 1st and 2nd spaces
What posterior intercostal vv join to form superior intercostal v
1-3
where do the rest of the posteiror intercostal vv drain into
azygos system
where do the anterior intercostal vv drain into
internal thoracic vv
what order do you find the structures of the neurovascular bundle of intercostal space
Vein superior
artery middle
nerve inferior
Where do the superficial structures of thoracic cavity drain lymphatics
axillary lymph nodes
what drains into the parasternal nodes
anteiror thoracic wall, superior portion of abdominal wall, superior surface of liver and medial portions of mammary gland
where do the parasternal nodes drain into
bronchomediastinal trunk
Where are the intercostal nodes found
near heads and necks of ribs
what drains into intercostal nodes
posterolateral thoracic wall
what do the intercostal nodes drain
thoracic duct of right lymphatic duct 1-6 spaces
7-11 spread to abdomen and enter cisterna chyli directly
What are the groups of diphragmatic nodes
anterior lateral and posterior
what diaphragmatic nodes drain to parasternal
anterior and lateral
where do the posterior diphragmatic nodes drain to
posterior mediastinal nodes
Where would you place a chest tub in the intercostal space to avoid the bundle
superior border- be careful for collateral branches
where is the pressure greatest in arterial supply of thorax. anteriorly or posterior
posterior because aorta supplies it
What are the three compartments of the thoracic cavity
2 lateral pulmonary cavities and a central mediastinum
boundaries of mediastinum
superior- superior thoracic aperture lateral- mediastinal parietal pleura inferior- diaphragm anterior- sternum and costal cartilages posterior- bodies of thoracic vertebra
what are the divisions of the mediastinum
superior and inferior.
anterior middle and posterior
what part of azygous system forms hemiazygous
lower third on left side. from junction of ascending lumbar and subcostal v, also drains 11,10,9 and crosses midline
what forms middle third azygous system
accessory hemiazygous v, spaces 5,6,7,8 (left) crosses midline
where to the top left intercostal spaces drain venous blood 1-4
directly into subclavian v
what are the boundaries of the superior mediastinum
superior- superior thoracic aperture
inferior- transverse plane
anterior- manubrium
posterior- anterior surface of vertebral bodes of TV1-TV4
where does the azygous v drain into
superior vena cava
are there valves in azygous system
no
what does the azygous system provide collaterally
connection between superior and inferior vena cava
what are the major structures in the superior mediastinum
thymus, brachiocephalic vv, superior vena cava, aortic arch and branches, trachea, esophagus, thoracic duct, sympathetic trunk, phrenic n, vagus n
where is the thymus found
posterior to manubrium
what is the primary lymphatic organ in infants
thymus
what supplies thymus arteriorly
internal thoracic and inferior thyroid vessels
what innervates the thymus
vagus and sympathetic trunk
what forms the brachiocephalic vv
subclavian and internal jugular vv
which brachiocephalic v is longer and why?
left traversely across superior mediastinum
what forms the superior vena cava
union of left and right brachiocephalic vv
at what level does the superior vena cava enter right atrium
third costal cartilage
Where does the aortic arch being (what segment level)
TV4 TV5 intervertebral space
where does the aorta arch
posteriorly to left over root of left lung
what are the 3 main branches of aortic arch
brachiocephalic trunk, left common carotid a and left subclavian a
where is the ligamentum arteriosum
passes from origin of left pulmonary a to arch of aorta
What levels are in phrenic and what does it inn
C3-5 motor inn to thoracic diaphragm
sensory to diaphragm, mediastinal pleura and pericardium
where does the phrenic n descend in relation to lungs
anterior to root of lungs
where does the vagus n descend in relation to lungs
posterior to root of lungs
what type of info does vagus carry
preganglionic PARAsympathetic to thoracic autonomic plexuses
what does the left vagus give off in the superior medistinum
left recurrent laryngeal
where does the left recurrent laryngeal travel
under arch of aorta just lateral to the ligamentum arteriosum, then superior
when the vagus nn approach esophagus in posterior mediastinum what do they become
left- anterior vagal trunk
right- posterior vagal rtunk
what n is compressed with hoarseness of voice
the recurrent laryngeal
what can impinge recurrent laryngeal
aoritic aneurysm, esophageal cancer, enlargement of mediastinal lymph nodes
What is the division of the anterior and posterior mediastinum
the pericardium
At what segmental level does the esophagus originate
CV6 as continuation of pharynx
in relation to trachea where does esophagus travel
left
where does the esophagus exit the thorax
through esophageal hiatus of diaphragm at TV10
Where is the cervical constriction
CV6 pharyngoesophageal
where is the thoracic constriction
TV4/5 broncho-aortic
where is the diaphragmatic constriction
TV10
what inn the esophagus autonomically
the esophageal autonomic plexus- SANS and PANS
where do the SANS of esophageal plexus come from
preganglionic nerve cell bodies at T2-T6
post ganglionic nerve cell bodies in sympathetic chain
How can esophageal pain and pain from MI present similarly
esophageal nn travel with cardiopulmonary splanchnic nn
what is the funciont of SANs on esophagus
vasoconstriction, and decreased gland secretion
Where are the postganglionic cell bodies of the PANs of esophagus
in its wall
what is the function of PANS on esophagus
vasodilation, increased gland secretion and increased peristalsis
Where does the descending aorta go in relation to midline
left
where does the descending aorta exit thorax
TV12 through aortic hiatus in thoracic diaphragm
What are the branches of the descending aorta
posterior intercostal 9 pari and subcostal aa bronchial a(2L, 1R) esophageal aa 3-5 unpaired pericardial and mediastinal aa superior phrenic aa (1 pair)
what percent of body does thoracic duct drain lymph
75%
where does the thoracic duct being
LV2 level from cisterna chyli
where does thoracic duct ascend in relation to esophagus
posterior
What branches come off ascending aorta
the coronary aa
At TV5 where does the thoracic duct traverse
across midline to left of esophagus and posterior to left common carotid a
Where are the postganglionic sympathetic nerve cell bodies found in abdomen
sympathetic chain ganglia
what is the smooth m in the trachea
trachealis
What nn supply the preaortic abdominal autonomic plexuses
thoracic splanchnic nn
what type of info is int thoracic splanchnic nn
preganglionic sympathetic nerve cell processes
3 parts of thoracic splanchnic nn and give cord levels in each
greater T5-T9
lesser T10-T11
least T12
