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)

Sternocostal joints: 1st to7th ribs to sternum

Interchondral joints: costal arch (cartilages of the 7th to 10th rib)

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 C1-

C2, 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 1/ trapezius

- 2/ latissimus dorsi

2nd layer 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: 1/ posterior intercostal aa. (for 3rd to 11th intercostal

spaces)

2/ subcostal a. Subclavian artery : 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)

Axillary artery: 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 1/ posterior intercostal Vein

(in kranio-caudal direction) 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/ phrenic

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: 1/ axillary (predominantly pectoral) lymph nodes

(important for metastases) 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