Thoracic wall-Skin

-Superficial fascia-deep fascia

Muscles of respiration:It includes muscles which are used in ordinary respiratiratory effortThis group includes 3 groups of muscles:1- 3 muscles which connect vertebral column to the ribs

- Serratus posterior superior -Serratus posterior inferior -Levator costorum 2- 3 groups of muscles which connect adjacent ribs: -External intercostal muscles (11 pairs) -Internal intercostal muscles (11 pairs) -Innermost intercostal3- The muscle which fill-in the thoracic outlet: the diaphragm which forms the thoraco-abdominal partition

1

2

3

Intercostal muscles:1- External intercostal muscle:Origin, insertion, direction2- Internal intercostal muscle:Origin, insertion, direction3- Innermost intercostal muscle + transversus thoracicOrigin, insertion, direction

Nerve supply and action

Respiratory Movement:

A- Quite inspiration:During inspiration, movements of thoracic wall and diaphragm result in an increase in all diameters of the thorax:1- Vertical diameter: It is increased by contraction (descent) of the diaphragm2- Transverse diameter: Bucket-handle movements3- Anteroposterior diameter: Pump- handle movements

B- Forced inspiration: more muscles are called in action; as muscles of head and neck and upper limb

C- Quite expiration: elastic recoil

D- Forced expiration: forcible contraction of muscles of anterior abdominal wall

Intercostal nerves: .They are the ventral rami of thoracic nerves.They are 11 pairs + subcostal nerves .3- 6 are called typical intercostal nerves. First, second and lower 5 intercostals are atypical intercostal nerves

VAN

Internal thoracic artery

Thoracic Aorta

VAN

Intercostal arteries:Anterior intercostal arteries: -2 in each space except lower 2 spaces - They are branches of internal thoracic artery and musculophrenic arteryPosterior intercostal arteries: - One in each space (11 in No) - They are branches of thoracic Aorta and costocervical trunk

Interernal mammary artery:Originates from the 1st part of subclavian arteryTerminates at the 6th CC-------and gives musculophrenic and superior epigastric arteries

Intercostal veins:Anterior intercostal veins -----internal thoracic veinPosterior intercostal veins: Rt-----azygos vein Lt----hemiazygos vein superior vena cava

VAN

Azygos vein

Hemiazygos vein