thorax (SEM 2) Flashcards
1st rib order of structures that pass above (on superior surface)
subclavian vein scalene anterior to scalene tubercle subclavian artery brachial plexus scalene medius
platysma
facial nerve (cervical) pulls corners of mouth down and mandible down to open mouth
what articulates with the facets of the vertebrae (Demi and costal)
costal transverse = tubercle of rib
demi + inferior demi of above vertebrae = rib head
true/false ribs
1-7 = true 8-12 = false 11-12 = floating
pectoralis major
pectoralis minor
major:
- ORIGIN: clavicle, sterno-costal cartilages, manubrium
- INSERTION: inter-tubercular groove
- INNERVATION : medial + lateral pectoral nerves
minor:
- ORIGIN: ribs 3-5
- INSERTION: coracoid process of scapula
- INNERVATION: onlymedial
serrates anterior
Origin: external surfaces of 1-8th ribs
Insertion: medial border of scapula
long thoracic nerve (winged scapula)
serrates anterior
Origin: external surfaces of 1-8th ribs
Insertion: medial border of scapula
long thoracic nerve (winged scapula)
long thoracic = C5-7 roots of brachial plexus
paralysis of diaphragm
HEMI-DIAPHRAGM:
each dome has a separate nerve supply
On x-ray the paralysed dome appears higher
Instead of descending on inspiration, the paralysed dome is pushed superiorly by the abdominal viscera that are being compressed by the active side
The diaphragm falls during expiration in response to the positive pressure in the lungs
paralysis of diaphragm
HEMI-DIAPHRAGM:
each dome has a separate nerve supply
On x-ray the paralysed dome appears higher
Instead of descending on inspiration, the paralysed dome is pushed superiorly by the abdominal viscera that are being compressed by the active side
The diaphragm falls during expiration in response to the positive pressure in the lungs
internal thoracic artery
aka internal mammary artery
from subclavian
travels lateral to sternum
gives off many branches
divides into musculophrenic and superior epigastric at 6th intercostal space
Thoraco-acromial artery and vein
Lateral thoracic artery(external mammary artery)
both from 2nd part of axilla
thoraco-acromial = anterior axillary wall
Lateral thoracic = anterior+medial axillary wall
-gives rise to lateral mammary
medial and lateral pectoral nerve origin
thoracodorsal nerve
medial - medial cord of brachial plexus
lateral - lateral cord of brachial plexus
(both for major; only medial for minor)
thoracodorsal - posterior cord (supplies lattisumus dorsi)
blood supply of breast
medial(from internal thoracic)
and lateral mammary(from lateral thoracic) artery/veins
lymphatic drainage of breast
axillary lymph nodes
APICAL:
–Apical - medial to axillary vein, superior to pectoralis minor
-Posterior(subscapular) - along subscapular vessels
-Infra-clavicular -
-Central - near base of axilla
-Anterior (pectoral)- deep to pectoralis major
-Lateral (humeral) - behind axillary vein
medial breast) drains to the parasternal lymph nodes or the opposite breast
how are the axillary lymph nodes divided in surgical practice
divided into 3 levels in relation to the pectoralis minor
- Level I : lateral to the lateral border of the muscle
- Level II: behind the muscle
- Level III: medial to medial border of muscle
deviation of the nipple and produce a leather-like, thickened appearance of the skin of breast - why?
Interference with the lymphatic drainage of the chest by cancer
anterior and posterior continuation of innermost intercostal muscles
anterior = transversus thoracis (sternocostalis)
-from posterior lower sternum/xiphoid to the inner costal cartilages of ribs 2-6
posterior = subcostalis (near angles of rib)
intercostal arteries (in each intercostal space there is 1 posterior, 2 anterior)
11 posterior(right are longer due to aorta being on left)
- Upper 2 arise from supreme intercostal artery (branch of costocervical)
- Lower 9 arise from back of thoracic aorta
9 anterior (2 in each space)
- Upper 6 arise from internal thoracic artery
- Lower 3 arise from musculophrenic artery
Upper anterior intercostal artery anastomoses with corresponding posterior intercostal artery.
Lower anterior intercostal artery anastomoses with collateral branch of the corresponding posterior intercostal artery.
intercostal nerves
within costal groove of ribs
In the 8th intercostal space, the nerve crosses deep to the costal margin and enters the anterior abdominal wall
The increasing obliquity of the intercostal nerves such that T10 supplies the level of the umbilicus and T12 supplies the skin at the supra-pubic level
chest drains
Thoracic Anaesthesia
CHEST DRAINS
above a rib to avoid structures in costal groove
done if haemothorax/pneumothorax/pleural effusion(inflammatory fluid)
THORACIC ANAESTHESIA
below a rib –> intercostal nerve between the paravertebral line (between transverse processes of vertebrae)
due to skin usually supplied by more than 1 nerve - doesn’t usually lead to complete loss of sensation unless >2 intercostal nerves are anesthetized
thoracic outlet syndrome
abnormal compression of brachial plexus
two roughened areas of 2nd rib
anterior - scalene anterior
posterior (superior) - scalene posterior
which ribs only articulate with one demi facet
1,10,11,12
axillary artery border
lateral border of 1st rib to inferior border of teres major
in a left tension pneumothorax which direction is the heart pushed towards
right
pleural recesses
during quiet breathing lungs don’t fill these spaces of pleural cavity
Costo-diaphragmatic recess
Costo-mediastinal recess
what does the pleural cavity become when lungs collapse
real space
fissures of lung
oblique
T3–>6th rib
horizontal (right) 4th
azygos lobe
on right where azygous vein may arch over the apex of right lung (instead of right hilum)
mediastinum compartments
superior and inferior (t4/5 tans-thoracic plane)
inferior
- anterior (thymus)
- middle
- posterior
difference in position of mediastinum structures when standing/lying down
When lying down:
- Arch of aorta lies superior to the transverse thoracic plane
- Bifurcation of the trachea is transected by the plane
- The central tendon of the diaphragm (or the diaphragmatic surface or inferior extent of heart) lies at the level of the xiphisternal junction and vertebra T9
When standing:
- Arch of aorta is transected by the thoracic plane
- Tracheal bifurcation lies inferior to the plane
- Central tendon of diaphragm may fall to the level of the middle of the xiphoid process and the T9/10 intervertebral disc
Transverse pericardial sinus
behind aorta and pulmonary trunk
Surgeons can stop or divert the circulation of blood of these arteries while performing surgery
Cardiac Tamponade
heart compression as fibrous pericardium is tough and cannot expand
Thus reduces CO and circulation of blood
coronary veins
Middle cardiac vein (back) - runs with posterior descending artery
Small cardiac vein (right) - runs with right coronary artery
Great cardiac vein (left) - runs with circumflex + LAD
sensory innervation of pleura
Both intercostal nerves (From anterior rami) and phrenic nerves (From C3, C4 and C5 spinal nerves) provide sensory innervation for the PARIETAL pleura. —> referred pain
The visceral pleura receive no sensory innervation
Insertion of a chest tube
Fluid (e.g. blood, pus) tends to accumulate in the costo-diaphragmatic recess (due to gravity). This would typically be removed with a chest tube. Chest tubes are inserted in the 5th intercostal space in the mid axillary line to avoid any vital structures.
Malignant mesothelioma
The mesothelium is the epithelial lining of the pleura. This is the cell origin of malignant mesothelioma, which is a rare cancer associated with asbestos exposure that has a particular poor prognosis.
how does sympathetic/parasympathetic innervation affect the bronchioles/ pulmonary vessels
sympathetic
- bronchodilation
- vasoconstriction
parasympathetic (vagus)
- bronchoconstriction
- vasodilation
3 hiatuses of diaphragm
T8- CAVAL through central tendon
T10- oesophageal
T12 - aortic behind diaphragm(median arcuate ligament)
vena cava/aorta not affected by muscle contraction
blood supply of diaphragm
superior supply
- superior phrenic (thoracic aorta)
- musculophrenic (internal thoracic)
- pericardiacophrenic (internal thoracic)
inferior supply
-inferior phrenic artery (from abdominal aorta)
ligaments of diaphragm + what passes through them
- Median arcuate ligament is attaches together via the right(to3rd) and left crus(2nd lumbar vertebrae)
- aorta*
- Medial arcuate ligament is from the vertebral body to the transverse process
- psoas major/ sympathetic chain*
- Lateral arcuate ligament is from the transverse process to the 12th rib
- quadratus lumborum*
recurrent pharyngeal nerve (branch of vagus) loops around what
left = aorta
right = subclavian
which vagus nerve make up posterior/anterior oesophageal plexus vagal trunk
left = anterior
right = posterior
splanchnic nerves (roots from sympathetic chain)
T5-T9 form the greater splanchnic nerve (to foregut)
T10-T11 form the lesser splanchnic nerve (to midgut)
T12 forms the least splanchnic nerve (to kidneys)
T1-T5 sympathetic chain form what plexuses
Cardiac plexus
Pulmonary plexus
Aortic plexus
Oesophageal plexus
3 constrictions of the oesophagus
- Upper/pharyngeal constriction
- Middle/aortic constriction
- Inferior/diaphragmatic constriction
where does thoracic duct start and empty
start = cisterna chyli
empties into the point where the internal jugular and left subclavian veins join in the neck
it runs up via aortic hiatus (diaphragm) and then behind oesophagus
tracheobronchial lymph nodes (4)
Tracheal - either side of trachea
Bronchial - in the angles between lower part of trachea and bronchi and in the angle between the 2 bronchi
(usually black due to smoke)
Bronchopulmonary - in the hilum of each lung
Pulmonary - in the parenchyma(lung tissue that also surrounds alveoli), on the larger branches of the bronchi
oblique pericardial sinus
transverse pericardial sinus
oblique pericardial sinus lies posterior to the left atrium, you can get to it if your finger from the apex (posterior side) of the heart and move it up, you will slip it into the oblique pericardial sinus.
transverse pericardial sinus is between the aorta and pulmonary arteries in front, and superior vena cava behind.
Pericardial reflections
parietal layer is continuous with visceral layer around the roots of the great vessels forming pericardial reflections
modulator band in the heart
in right ventricle
carries the right bundle branch of the AV bundle of the conduction system of the heart to the anterior papillary muscle
most common place for aortic Coarctation and what happens if it occurs inferior to this site
near the point of attachment of the ligamentum arteriosum
collateral circulation may develop between the proximal and distal parts of the aorta through the intercostal and internal thoracic arteries.
branches of thoracic aorta
Visceral
- Bronchial arteries
- Oesophageal arteries
- Pericardial arteries
Parietal
- Superior phrenic arteries
- Posterior intercostals arteries (lower 9 pairs)
- Subcostal arteries (1 pair)
further triangle divisions of anterior triangle
Carotid
Muscular
Digastric
Sub-mental
torticollis
abnormal position of neck for a long time due to no innervation to move on one side
(eg. no accessory nerve innervation to SCM)
azygos system
+ tributaries of azygous vein
drainage of posterior thoracic wall:
Right:
- superior intercostal vein(2nd-4th intercostal spaces) drains to azygos vein
- azygos vein drains into SVC
left:
- Hemiazygos(left ascending lumbar+ left subcostal) - drains to azygos
- Accessory hemiazygos(4th-8th Posterior intercostal) - drains to azygos
- Left superior intercostal - drains 2nd-4th intercostal spaces to the left brachiocephalic vein
azygos vein = RIGHT subcostal vein + RIGHT ascending lumbar vein (tributaries from 4th-11th,subcostal, hemiazygos,a.hemiazgous, oesophageal and right bronchial)
what is the 1st intercostal (posterior) vein called
SUPREME intercostal vein
