Topographical Anatomy of the Thorax

TOPOGRAPHICAL ANATOMY

THE THORAX

INTRODUCTION

The trunk of the body is divided by the diaphragm into an upper part, called the thorax, and a lower part called the abdomen.

Upper part

Lower part

THORACIC CAGE

Clinical correlate

THE LUNGS

Right and Left Pleural Cavities

• Parietal Pleura• Visceral (Pulmonary) Pleura• Parietal– Costal– Mediastinal– Diaphragmatic– Cupola

• Connecting Pleura

Pleural Cavities

Pleural Cavities

Lungs

• Pair of Cone-shaped organs • Lie in pleural cavity• Weigh approx 800g– 90% air– 10% tissue

• Left lung is narrower• Right lung is shorter

Right Lung

Right Lung

Left Lung

Left Lung

Left Lung

Lungs

• Apices-extend 1-2 cm past clavicles• At end-expiration

– 6th rib – midclavicular– 8th rib – laterally

• Posteriorly– Tops is at 1st vertebra

• Inferior border– Rises & falls betwee 9th & 12th rib

MEDIASTINUM

The median septum of the thorax between the two lungs.

DIVISIONS OF THE MEDIASTINUM

Split into two for descriptive purposes:Superior and Inferior Mediastina

Lower border of T4

Sternal angle

CONTENTS OF THE MEDIASTINUM

Superior mediastinum:EsophagusTracheaArch of AortaBig branches of Aortic archBrachiocephalic (innominate) veinsUpper half of superior vena cavaPhrenic nervesVagi nerves

Middle mediastinum:PericardiumHeartPulmonary trunkAscending AortaLower half of SVCUpper part of IVCBifurcation of tracheaPosterior mediastinum:Esophagus.Descending thoracic Aorta.Azygos and hemiazygos veins.Vagi, greater, lesser and least splanchnic nerves.

THE CARDIOVASCULAR SYSTEM

“Cardio” = Heart“Vascular” = Vessels

SIZE, LOCATION, AND SURFACES

COVERINGS OF THE HEARTPericardiumMyocardiumEndocardium

MAJOR VESSELS OF THE HEART

Anterior view

Posterior view

GROSS ANATOMY

MYOCARDIAL THICKNESS AND FUNCTION

R.A

R.V

L.A

L.V

HEART VALVES

ATRIOVENTRICULAR VALVES

SEMILUNAR VALVES

BLOOD SUPPLY TO THE HEART

VENOUS DRAINAGE THE HEART

INNERVATION OF THE HEART

INNERVATION OF THE HEART

1- Sympathetic innervation: Stimulates heart rate (tachycardia) coronary vasodilatation

2- Paraympathetic innervation: Slows heart rate (bradycardia) Coronary vasoconstriction

3- Pain fibers: upper thoracic segments of the spinal cord

CLINICAL ANATOMY

CORONARY ARTERY DISEASEHeart muscle receiving insufficient blood supply

narrowing of vessels---atherosclerosis, artery spasm or clotatherosclerosis--smooth muscle & fatty deposits in walls of arteries

Treatmentdrugs, bypass graft, angioplasty, stent

BY-PASS GRAFT

MI = MYOCARDIAL INFARCTIONdeath of area of heart muscle from lack of O2 replaced with scar tissueresults depend on size & location of damage

BLOOD CLOTuse clot dissolving drugs streptokinase or t-PA & heparinballoon angioplasty

ANGINA PECTORISheart pain from ischemia (lack of blood flow and oxygen)

of cardiac muscle

PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY

CONGESTIVE HEART FAILURE (CHF)

Congestive heart failure (CHF) is caused by:Coronary atherosclerosisPersistent high blood pressureMultiple myocardial infarctsDilated cardiomyopathy (DCM) – main pumping

chambers of the heart are dilated and contract poorly.

CONGENITAL HEART DEFECTS

ATRIAL SEPTAL DEFECT

ARTIFICIAL HEART

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