THORACIC CAVITY

ANATOMY OF THETHORAX

Dr. Heba Al-Hussaini

Assistant professor

Department of Anatomy

Faculty of Medicine

11/12/2012

OBJECTIVES

•Describe the thoracic wall.

•Describe the thoracic apertures.

•Describe the organization of the thoraciccavity – pleural cavities and mediastinum.

•Describe the organization of the thoracicviscera.

THE THORAXTHE THORAX

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0001.jpg$

•Function of thoraciccage:

1- Protect thoracic organs.

2- Support the pectoralgirdle.

3- Provide attachments formuscles

4- Take part in breathing.

5- Conduit for structuresthat pass to and out ofthorax

THE THORACIC WALLTHE THORACIC WALL

$C:\Users\h.alhussaini\Pictures\thoracic region\sca01.jpg$

•The skeletal elements of the thoracic wall consist of 12 thoracic vertebraeposteriorly, 12 pairs of ribs laterally and the sternum anteriorly.

$C:\Users\h.alhussaini\Pictures\thoracic region\123.jpg$

SUPERIOR THORACIC APERTURESUPERIOR THORACIC APERTURE

$C:\Users\h.alhussaini\Pictures\thoracic region\123.jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0011.jpg$

THORACIC OUTLET SYNDROMETHORACIC OUTLET SYNDROME

$C:\Users\h.alhussaini\Pictures\thoracic region\11a.jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\11b.jpg$

•The axillary inlet to the upper limb lies on each side of the superior thoracic aperture.

•Cervical rib syndrome results from compression of the inferior trunk of brachial plexus.

•The costoclavicular syndrome results from compression of the subclavian artery betweenthe clavicle and 1st rib.

INFERIOR THORACIC APERTUREINFERIOR THORACIC APERTURE

•Generally muscle fibers of the diaphragm arise radially from the margins of the inferior thoracicaperture, and converge into a large central tendon.

•Attachment of the diaphragm: xiphoid process, distal cartilaginous ends of ribs VII to X, ribs XI and XII,vertebrae of lumber region.

$C:\Users\h.alhussaini\Pictures\thoracic region\123.jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\Copy (3) of scan0018.jpg$

DIAPHRAGM SUPERIORDIAPHRAGM SUPERIOR

VIEW VIEW

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0010.jpg$

MAJOR STRUCTURES THATPASS THROUGH THEDIAPHRAGMMAJOR STRUCTURES THATPASS THROUGH THEDIAPHRAGM

$C:\Users\h.alhussaini\Pictures\thoracic region\Copy (2) of scan0018.jpg$

•The esophagus pass through the muscular part of the diaphragm and the inferior venapass through the central tendon of the diaphragm whereas the aorta passes posteriorto the diaphragm.

THE THORACIC CAVITYTHE THORACIC CAVITY

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0014.jpg$

•The thoracic cavity is subdivided into three major compartments.

•The pleural cavities are completely separated from each other by themediastinum.

MEDIASTINUMMEDIASTINUM

$C:\Users\h.alhussaini\Pictures\thoracic region\1.jpg$

•The sternal angle is used to find the position of the rib II as reference for counting ribs.

•Anterior mediastinum contains a portion of thymus and fat.

•Middle mediastinum contains the pericardium and heart.

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0025.jpg$

CONTENT OF THE MEDIASTINUMCONTENT OF THE MEDIASTINUM

•Superior mediastinum contains the thymus, Superior vena cava, brachiocephalicveins, arch of aorta and roots of its major branches.

•Posterior mediastinum contains the esophagus, descending aorta, azygos vein,thoracic duct, sympathetic trunk and thoracic splanchnic nerves.

$C:\Users\h.alhussaini\Pictures\CVS\Figure0207.jpg$

$C:\Users\h.alhussaini\Pictures\CVS\Figure0202.jpg$

PERICARDIUMPERICARDIUM

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0015.jpg$

•The pericardium is a fibroserous sac surrounding the heart and the roots of the great vessels.

•Consists of two components: 1- fibrous pericardium is a tough connective tissue outer layer that definesthe boundaries of the middle mediastinum, 2- the serous pericardium is thin and consist of the parietallayer lines the inner surface of the fibrous and visceral layer adheres to the heart and forms its outercovering.

BORDERS OF THE HEARTBORDERS OF THE HEART

•Right border formed by right atrium and extend between the SVC & IVC.

•Inferior border formed by the right ventricle and slightly by the left ventricles.

•Left border formed mainly by the left ventricle and slightly by left auricle.

•Superior border formed by the right and left atria and auricles.

$C:\Users\h.alhussaini\Pictures\CVS\Untitled-2a.jpg$

Posterior view

Anterior view

• Anterior formed (sternocostal) mainly by Rt. Ventricle.

• Inferior formed (diaphragmatic) mainly by the Lt. ventricles and partly by Rt. Ventricle.

• Posterior (base) formed by the Lt. atrium.

$E:\cardiovascular\heart structure.jpg$

$E:\cardiovascular\heart-posterior-view.gif$

Lt. Atrium

THREE SURFACES OF THE HEART THREE SURFACES OF THE HEART

PLEURAL CAVITYPLEURAL CAVITY

$C:\Users\h.alhussaini\Pictures\thoracic region\Copy (2) of scan0017.jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\Copy of scan0017.jpg$

•Each pleural cavity is lined by the pleura which is divided in to two types:

•1- Parietal pleura associated with the walls of the pleural cavity.

•2- visceral pleura which reflects from the medial wall and onto the surface of the lung tocover the lung.

ARTERIES OF THE THORACIC WALLARTERIES OF THE THORACIC WALL

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0009.jpg$

•Vessels that supply the thoracic wall consist of posterior intercostal which originatefrom the aorta and anterior intercostal arteries which originate from the internalthoracic (branch of subclavian).

VEINS OF THE THORACIC WALLVEINS OF THE THORACIC WALL

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0008.jpg$

•Most intercostal veins ends in the azygos venous system of veins which ultimately drains into the SVC.

•The 1st -3rd superior intercostal veins drain into brachiocephalic vein.

LYMPHATIC DRAINAGE THORACICWALLLYMPHATIC DRAINAGE THORACICWALL

$C:\Users\h.alhussaini\Pictures\thoracic region\33.jpg$

•Lymphatic vessels of the thoracic wall drain mainly in to parasternal, intercostal and diaphragmaticlymph nodes.

•Parasternal nodes drains into bronchomediastinal and intercostal nodes into thoracic duct.

$C:\Users\h.alhussaini\Pictures\thoracic region\Copy (3) of scan0015.jpg$

TRANSVERSE SECTION THROUGH THE SUPERIORMEDIASTINUM AT THE LEVEL VERTEBRA TIIITRANSVERSE SECTION THROUGH THE SUPERIORMEDIASTINUM AT THE LEVEL VERTEBRA TIII

$C:\Users\h.alhussaini\Pictures\thoracic region\ct6.jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\ct4.jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\ct3.jpg$

TRANSVERSE SECTION THROUGH THESUPERIOR MEDIASTINUM AT THELEVEL VERTEBRA TVTRANSVERSE SECTION THROUGH THESUPERIOR MEDIASTINUM AT THELEVEL VERTEBRA TV

$C:\Users\h.alhussaini\Pictures\thoracic region\1 (3).jpg$

$C:\Users\h.alhussaini\Pictures\thoracic region\1a.jpg$

CLINICAL APPLICATIONCLINICAL APPLICATION

$C:\Users\h.alhussaini\Pictures\thoracic region\scan0024.jpg$

THANK YOUTHANK YOU