ECHO FINAL

• 1. Superior
• 2. Anterior
• 3. Middle
• 4. Posterior

Lies above the sternal angle to the inferior border of the 4th thoracic vertebrae.

Contains:

• AO Arch
• Innominate A 
• Innominate V'(s)
• SVC
• Trachea
• Esophagus
• CCA Prox
• Subclavian A'(s) 
• Subclavian V'(s)

A very small section that lies anterior to the heart or pericardial sac.

Contains:

• Lymph nodes
• Mucles
• Small blood vessels.

Contains:

• Heart
• Asc AO
• Pericardium
• Terminal end of SVC
• Pulmonary A
• Terminal parts fo the Rt & Lt Pulmonary V'(s)
• Phrenic nerves

Contains:

• Desc Thoracic AO
• Rt & Lt Main Bronchi
• Esophagus
• Azygous V'(s)
• Hemiazygous V'(s)
• Splenic nerves
• Thoracic lymph duct

• Manubrium (Top portion)
• Body (Middle portion)
• Xiphoid Process (Bottom portion)

Scalene muscles:

Aid in inspiration by elevating the 1st & 2nd ribs.

External Intercostal muscles:

11 pairs elevate the ribs durin inspiration and increase lateral and anterioposterior dimensions of the thorax.

Internal Intercostal muscles:

11 pairs serve as antagonists to the external intercostals. They decrease the lateral and anteroposterior dimensions of the thoracic cavity by drawing adjacent ribs together during forced expiration.

Diaphragm:

Most important muscle of inspiration.

• vertically
• horizontally

Average length: 12 cm

Greatest width: 8-9 cm

Smallest width: 6 cm

Weight: 

• Males 280-340 grams OR 10.58 oz
• Females 230-280 grams OR 8.8 oz