Download Thorax – skeleton, joints, muscles, arterial blood supply, venous and

Ingrid Hodorova, Assoc. Prof., MD, PhD.
Thorax – skeleton, joints, muscles, arterial blood supply, venous and
lymphatic drainage, innervation, regional anatomy
Thorax
upper part of the trunk
box for vital organs
Boundaries
external upper:
1/ jugular notch
2/ clavicule
3/ acromion of scapula
4/ spine of C7 (vertebra prominens)
external lower:
1/ xiphoid process
2/ left and right costal arches
3/ vertebra Th12
internal upper:
1/ superior thoracic aperture (made from jugular notch, 1st pair of ribs,
vertebra Th1)
internal lower:
1/ inferior thoracic aperture (full filed by diaphragm, which extends on
the right side to the 4th intercostal space (ICS), on the left side extends
to the 5th ICS)
Arteficial lines on the thorax
unpaired:
1/ anterior median line
2/ posterior median line
paired:
1/ sternal line
2/ parasternal line
3/ mid-clavicular line
4/ anterior axillary line
5/ midddle axillary line
6/ posterior axillary line
7/ scapular line
8/ paravertebral line
Thoracic wall
1st layer (proper thoracic wall):
1/ osteothorax (ribs, sternum, Th vertebrae + their joints)
2/ proper mm. of thoracic wall (intercostal muscles,
transversus thoracis, subcostalis)
3/ intrinsic mm. of the back (erector spinae m.)
4/ intercostal neuro-vascular bundle (vein, artery, nerve)
5/ endothoracic fascia
6/ parietal pleura
2nd layer (middle):
1/ pectoral fascia
2/ thoracohumeral mm.
3/spinohumeral mm.
4/spinocostal mm.
3rd layer (superficial):
1/ skin
2/ subcutaneous tissue + mammary gland
3/ superficial structures (supraclavicular nn.,
intercostobrachial nn., thoracoepigastric vv.)
Osteothorax
Thoracic vertebrae (12):
1/ body - costal facets,
2/ arch - vertebral notches – intervertebral foramen,
vertebral foramen
3/ processes – transverse, sup. and inf. articular, spinous
Ribs (12 pairs):
1/ head - articular facet of the head
2/ neck
3/ body – tubercle, articular facet, costal crest, costal
sulcus
1st rib - groove for subclavian artery, tubercle for scalenus
anterior m., groove for subclavian vein
True ribs: 1st to 7th
False ribs: 8th to 10th
Floating ribs: 11th to 12th
Sternum:
1/ manubrium — jugular notch, clavicular notch, costal
notch (1st and 2nd ribs)
2/ body (costal notches 2nd to 7th ribs)
3/ xiphoid process
sternal angle - attachment the 2nd pair of ribs
Joints of the ribs
Costovertebral joints:
1/ joints of the heads of the ribs (head of the ribs to the
body of the thoracic vertebrae)
2/ costotransverse joints (costal tubercle and transverse
process)
1st to7th ribs to sternum
costal arch (cartilages of the 7th to 10th rib)
Sternocostal joints:
Interchondral joints:
Connections of the vertebral column
Syndesmosis:
1/ short ligaments: interspinous, intertransverse, flava
2/ long ligaments: anterior and posterior longitudinal
ligamens
Synchondrosis:
Intervertebral discs, between vertebral bodies (nucleus
pulposus, anulus fibrosus) total numer 23, 1st between C1C2, last one between L5-S1
Synostosis:
sacrum
Joints of vertebral column:
between superior et inferior articular processes
Curvatures of vertebral column: 1/ in sagittal plane
lordosis - cervical and lumbar
kyfosis - thoracic and sakral
2/ in frontal plane
scoliosis
Muscles of the thorax
Thoracohumeral muscles:
1/ pectoralis major
2/ pectoralis minor
3/ serratus anterior
4/ subclavius
Mm. of proper thoracic wall:
1/ intercostal (external, internal, intimi)
2/ transverse thoracis m.
3/ subcostal mm.
Diaphragm:
1/ muscular portion - sternal part, costal part, lumbar part
oesophageal hiatus (Th10) – oesophagus, vagus nn.,
oesophageal vv., phrenocoabdominal br. of left phrenic n.
aortic hiatus (Th12) – aorta thoracic duct,
2/ central tendon
opening for inferior vena cava (Th8) – inferior vena
cava, phrenocoabdominal br. of right phrenic n.
innervation - phrenic nerve
through crus of lumbar parts pass: azygos v., hemiazygos
v., sympathetic trunk, splanchnic nn. (greater, lesser and
least)
Muscles of the back
Spinohumeral mm.: 1st layer
2nd layer
1/ trapezius
2/ latissimus dorsi
1/ levator scapulae
2/ rhomboid major
3/ rhomboid minor
Spinocostal mm:
1/ posterior superior serratus
2/ posterior inferior serratus
Intrinsic mm. of the back:
1/ m. erector spinae
Arterial blood supply of the thorax
Thoracic aorta:
Subclavian artery :
Axillary artery:
1/ posterior intercostal aa. (for 3rd to 11th intercostal
spaces)
2/ subcostal a.
1/ internal thoracic a.:
anterior intercostal aa.
musculophrenic a.
superior epigastric a. (anastomoses with inferior
epigastric a.)
2/ costocervical trunk
supreme intercostal a. (for 1st and 2nd intercostal spaces)
1/ thoracoacromial a.
2/ lateral thoracic a.
3/ thoracodorsal a.
Veinous drainage of the thoracic wall
Azygos v. - right posterior intercostal vv., right superior intercostal v., arch of
azygos v., drains into superior vena cava.
Right supreme intercostal v., drains into right brachiocephalic v.
Hemiazygos and accessory hemiazygos veins - left posterior intercostal vv.,
drain into azygos vein.
Left superior intercostal v., drains into left brachiocephaliv v.
Left supreme intercostal v., drains into left brachiocephalic v.
Internal thoracic vv. , left drains into left brachiocephaic v., right drains into superior vena
cava
Thoracoepigastric vv., they form lateral thoracic v., it drains into axillary v.
Vertebral venous plexus — external and internal
Veins of the thoracic wall form important cavo-caval and porto-caval anastomoses!
Neurovascular bundle in intercostal spaces – VAN
VAN is made from
(in kranio-caudal direction)
1/ posterior intercostal Vein
2/ posterior intercostal Artery
3/ intercostal Nerve
Runs between:
1/ endothoracic fascia and internal intercostal membrane
(in dorso-ventral direction)
2/ inside internal intercostal mm., separates innermoust
(intimi) intercostal mm.
3/ between endothoracic fascia and internal intercostal mm.
Lymphatic drainage of the thoracic wall
Parietal lymph nodes:
1/ intercostal
2/ parasternal
3/ phreni c
Innervation of the thoracic wall
Thoracic wall is supplied from nerves of brachial plexus and from intercostal nn.
Sensory:
1/ intercostals nerves
2/ supraclavicular nerves
3/ intercostobrachial nerves
Motor:
1/ phrenic n. (diaphragma)
2/ intercostals nn. (intercostal mm., transverse thoracic
m., subcostal m.)
3/ long thoracic n. (serratus anterior m.)
4/ medial and lateral pectoral nn. (pectoralis major and
minor)
5/ thoracodorsal n. (latissimus dorsi m.)
6/ dorsal brr. of spinal nerves (intrinsic muscles of the
back)
7/ accessory n. (trapezius m.)
8/ subclavian n. (subclavius m.)
Mammary gland
Blood supply
1/ pectoral brr. of thoracoacromial a.
2/ lateral mammary brr. of lateral thoracic a.
3/ medial mammary brr. (perforating brr.) of internal
thoracic a.
Innervation:
1/ lateral mammary br., from intercostal nn.
2/ medial mammary br., from intercostal nn.
3/ medial and intermediate supraclavicular nn., from
cervical plexus
Lymphatic drainage:
(important for metastases)
1/ axillary (predominantly pectoral) lymph nodes
2/ parasternal lymph nodes
3/ supraclavicular (deep cervical) lymph nodes
4/ superficial inguinal lymph nodes
Mediastinum
-
part of the thoracic cavity between two pleural cavities (right and left)
Borders
ventral: sternum + costal cartilages + transverse thoracis m.
dorsal: thoracic vertebrae (bodies)
caudal: diaphragm
lateral: mediastinal pleura right and left
cranial: superior thoracic aperture
Division
- horizontal line, which connects sternal angle and intervertebral disc between Th4-5
into:
superior mediastinum
inferior mediastinum – by pericardium is divided into: anterior mediastinum
middle mediastinum
posterior mediastinum
Superior mediastinum
-
communicates with anterior mediastinum and posterior mediastinum
content:
- thymus
- right brachiocephalic vein
- left brachiocephalic vein + its tributaries
- superior vena cava + its tributaries
- right and left phrenic nerve – different passage
- right and left vagus nerve – different course, left recurrent laryngeal n.
- aortic arch – course, branches: brachiocephalic trunk, left common
carotid a., left subclavian artery, bronchial aa.
- trachea (thoracic part)
- oesophagus
- thoracic duct
- superficial cardiac plexus
- sympathetic trunk (covered by endothoracic fascia)
- anterior mediastinal lymph nodes
Anterior mediastinum
- fissure behind the body of sternum and in front of pericardium, it communicates with
superior mediastinum
content:
- thymus
- parasternal lymph nodes
- superior et inferior sternopericardiac ligaments
Middle mediastinum
- it is separated by pericardium from other parts of mediastinum (from posterior
mediastinum is also separated by bronchopericardiac membrane)
content:
- heart + pulmonary trunk
- ascending aorta
- left and right pulmonary veins
- superior et inferior vena cava
- deep cardiac plexus
- left and right phrenic nerves + pericardiacophrenic vessels
(between pericardium and mediastinal pleura)
- tracheal bifurcation
- tracheobronchial lymph nodes
Posterior mediastinum
borders:
anterior - pericardium, bronchopericardiac membrane
posterior - Th5-Th12
inferior - diaphragm
superior - imaginary line: intervertebral disc Th4-5 and sternal angle,
direct communication with superior mediastinum (important for the
spreading of inflammation to the neck and to the abdominal cavity)
content:
thoracic aorta
oesophagus
anterior et posterior vagal trunk
thoracic duct
azygos vein
hemiazygos vein
accessory hemiazygos vein
sympathetic trunk (covered by endothoracic fascia!)
greater, lesser et least splanchnic nerve
posterior mediastinal lymph nodes