Mediastinum · 2020. 3. 25. · Competencies & special learning objectives • AN21.11 Mention...

Mediastinum Dr. P. S. Mittal

Associate Professor, DeptARTMENt of Anatomy, GIMS

1

Competencies & special learning objectives

• AN21.11 Mention boundaries and contents of the superior, anterior, middle and posterior mediastinum

• Specific Learning Objectives – AN21.11.1 List the boundaries of superior mediastinum.

– AN21.11.2 Enumerate the contents of superior mediastinum.

– AN21.11.3 List the boundaries of anterior mediastinum.

– AN21.11.4 Enumerate the contents of anterior mediastinum.

– AN21.11.5 List the boundaries of middle mediastinum.

– AN21.11.6 Enumerate the contents of middle mediastinum.

– AN21.11.7 List the boundaries of posterior mediastinum.

– AN21.11.8 Enumerate the contents of posterior mediastinum.

2

DEFINITION • It is a partition between

the right & left pleural sacs.

• It includes all the structures which lie in the intermediate compartments of the thoracic cavity.

3

Concept

• All of organs between the left and right mediastinall pleurae is called mediastinum.

• It extends from the sternum in front to the vertebral column behind, and from the thoracic inlet above to the diaphragm below.

4

Subdivisions

• Superior mediastinum

• Inferior mediastinum

– Anterior mediastinum

– Middle mediastinum

– Posterior mediastinum

5

• It is divided by a horizontal plane extending from sternal angle to lower border of 4th thoracic vertebra into:

1. Superior mediastinum: above the plane

2. Inferior mediastinum: below the plane, it is subdivided into:

– Anterior mediastinum: in front of pericardium – Middle mediastinum: contains heart &

pericardium – Posterior mediastinum: behind pericardium

SubdiviSionS ConTd…

6

SubdiviSionS ConTd…

7

8

9

SUPERIOR MEDIASTINUM

• It is the part of Mediastinum above the horizontal plane extending from sternal angle to lower border of 4th thoracic vertebra.

BOUNDARIES:

• Anterior: manubrium sterni

• Posterior: Upper 4 thoracic vertebrae

• Superior: Plane of thoracic inlet

• Inferior: Horizontal plane

• On each side: Pleura

10

Contents of Superior mediastinum

• In the Anterior part:

– Thymus

– Three veins

• Left brachiocephelic v.

• Right brachiocephelic v.

• Superior vena cava

11

A. In the Middle part:

• Aotic arch and its three

branches:

1. Brachiocephalic

2. Left common carotid

3. Left subclavian arteries

• Phrenic nerve

• Vagus nerve

Contents of Superior mediastinum contd…

12

• In the Posterior part:

– Esophagus

– Trachea

Contents of Superior mediastinum contd…

13

• FROM BEHIND FORWARD:

1. Esophagus

2. Trachea

3. Arch of aorta & its 3 branches: brachiocephalic, left common carotid & left subclavian arteries

4. Right & left brachiocephalic veins & superior vena cava

5. Thymus gland

Contents of Superior mediastinum contd…

14

OTHER CONTENTS: – Muscles:

1. Sternohyoid 2. Sternathyroid 3. Longus colli

– Nerves:

1. Right & left vagus 2. Right & left phrenic 3. Right & left sympathetic trunks 4. Left recurrent laryngeal

– Lymphatic structures:

1. Thoracic duct 2. Lymph nodes (Brachiocephalic & Tracheobranchial)

Contents of Superior mediastinum contd…

15

17

SUPERIOR MEDIASTINUM

19

T.S. at tHe level of T4

20

CLINICAL ANATOMY

21

CLiniCAL AnAToMY ConTd… Compression of mediastinal structures by any mass give rise to group of symptoms known as MEDIASTINAL SYNDROME

22

THANKS