Thoracic Wall Lecture - PowerPoint Presentation

Slide1

Thoracic

Wall

Slide2

Lecture

Objectives

Describe the shape and outline of

the

thoracic cage

including

inlet

and

outlet

.

Describe the

anatomical

landmarks of

the

anterior chest

wall

.

List various structures

making the

thoracic

wall.

Make

a

list

of

muscles

of the

thoracic wall

including their nerve and blood supply and their

actions.

List various

parts

of

the

thoracic

vertebrae

and name its

characteristic

features.

Describe the

sternum

with

its

joints

.

Classify

ribs

, name their

various

parts and

compare

them with

each

other.

Define

intercostal

spaces

and discuss their various

components

including

intercostal

muscles.

Describe the

diaphragm

,

its origin, insertion, function, nerve and blood

supply.

Study openings in the

diaphragm

and

structures

that

pass

through.

Slide3

Thoracic

Cage

Bony cage

flattened

from front to backSternum (breastbone)Ribs1‐7 are true ribs (vertebrosternal)8‐10 are false ribs (vertebrochondral)11‐12 are floatingCostal cartilagesBodies of the thoracic vertebrae

Slide4

Skeleton

of Thoracic

Wall

Slide5

Thoracic

Cage: Functions

Enclose

and

protect the organs in the thoracic and abdominal cavitiesProvide support for the bones of the upper limbsPlay a role in breathing

Slide6

S

ternum

Manubrium

1st

& 2nd ribsClavicular notch (sternoclavicular joint)Sternal angle– T3‐T4BodyCostal cartilages of 2‐7 ribsXiphoidOssifies by 40CPR positionAbdominal mm.T9

Slide7

S

t

ernum

Slide8

Ri

bs

Increase

in

length from ribs 1‐7, thereafter decreasingHead and tubercle articulate with facetsBody with costal groove containing nerve & blood vesselsIntercostal spaces contain intercostal muscles

Slide9

Ri

bs

Typical

ribsLong & twistedRounded superior edgeGrooved inferior edge (costal groove)Head (2 facets 2‐9, 1 facet 1, 10‐12), neck, tubercle, shaft & angle

Slide10

Ri

bs

Atypical

ribs

1st ribWidest, shortest, most curved true ribArticulate with T1Surface marking …11th and 12thNo neckNo tubercleFloating

Slide11

Thoracic

Wall: Joints

Cartilaginous

JointsJoints of sternumManubriosternal joint (2°)Xiphisternal jointCostochondral joints1st sternocostal jointSynovial Joints (plane joints)Joints between ribs and thoracic vertebrae2nd ‐7th sternocostal joints6th – 10th interchondral joints

Slide12

Joints

of the Heads of

Ribs

2‐9

ribs2 synovial jointsWith the corresponding vertebra and one aboveIntra‐articular ligamentBetween head and IVD1, 10‐12 ribs1 synovial joint with the corresponding vertebra

Slide13

Costotransverse

Joint

Joints

of the

tubercles (1‐10 ribs)– With the transverse process of the corresponding vertebra

Slide14

Thoracic

Wall: Joints

Slide15

Slide16

Thoracic

Apertures

Slide17

Superior

Thoracic Aperture

Between

thoracic cavity

and the root of the neckBoundaries ..Orientation ..ContentTracheaEsophagusNerves & BVsLungs & pleuraeSuprapleural membraneClose the sides of the opening above the parietal pleurae

Slide18

Superior

Thoracic Aperture

Slide19

Inferior

Thoracic Aperture

Slide20

Intercostal

Spaces

Between successive

ribsContain the intercostal mm.External , internal, and innermost intercostal mm.Neurovascular bundle run superficial to the innermost intercostal m.Arranged from superior to inferior as vein, artery , and nerve

Slide21

Intercostal

Muscles

Nerve supply:

intercostal

nervesThree layersExternal intercostalOrientationAnterior (external) intercostal membraneHelps in inspirationInternal intercostalOrientationPosterior (internal) intercostal membraneHelps in expirationInnermost intercostalCross more than one intercostal spacesAttached to the endothoracic

fascia

internally

–

Attached

to parietal

pleura

Divided

into

three

parts

Works

with the

internal

intercostal

Slide22

Accessory

Muscles of Respiration

Transversus

thoracisHelp in expirationPectoralis major, pectoralis minor, serratus anterior, scalene mm.May help in inspiration

Slide23

Accessory

Muscles of Respiration

Levator

costarumBetween the transverse processes and the ribsNerve supply: posterior rami of thoracic spinal nervesHelp in inspirationSerratus posterior superior m.Deep to rhomboidsNerve supply: 1‐4 intercostal nervesHelp in inspirationSerratus posterior inferior m.Deep to latissmus

dorsi

Nerve supply:

last

4

intercostal

nerves

Help

in

expiration

Slide24

Slide25

Diaph

ragm

Physical

barrier

between thoracic and abdominal cavitiesFunctionsInspirationAbdominal pressureAbdominothoracic pumpDome like shapePeripheral muscularReach up to the 5th ribCentral tendonAt level of xiphisternal joint

Slide26

Sternal

‐ posterior

surface

of xiphoid

processCostal‐ the lower six ribs and their costal cartilagesVertebral‐Right crus‐ bodies of L1‐L3Left crus‐ bodies of L1‐L2Arcuate ligamentsMedial‐ L2 (body) to L1 (transverse process)Lateral‐ L1 (transverse process) to 12th ribMedian‐ connects crura anterior to aortaOrigin of the

diaphragm

Slide27

Openings

in the Diaphragm

Aortic

opening‐

T12Between cruraContentAorta, thoracic duct, & azygos veinEsophageal opening‐ T10In right crusContentEsophagus, vagi, BVs & lymphatic vesselsCaval opening‐ T8ContentIVC, branches of right phrenic nerve

Slide28

Openings

in the Diaphragm

Other

structures

pass the diaphragmSplanchnic nerves – through cruraSympathetic trunk – medial arcuate lig.Subcostal nerve – lateral arcuate lig.Superior epigastric vessels – between sternal & costal origins

Slide29

Diaphragm:

Innervation

Motor

Phrenic nerves

(C3‐C5)SensoryCentrally – phrenic nervesPeripherally – intercostal nerves (T7‐ T12)

Slide30

Diaphragm:

Blood Supply

Slide31

Slide32

Arteries of

Thoracic

Wall

Posterior

intercostal aa.1‐2 ← superior intercostal← costocervical trunk ← 2nd part of supclavian3‐12 ←descending thoracic aortaAnterior intercostal aa.1‐6 ← internal thoracic←1st part of subclavian7‐12 ← musculophrenic← internal thoracic

Slide33

Slide34

Veins

of Thoracic

Wall

Posterior

intercostal veinsDrain into azygos and hemiazygos veinsAnterior intercostal veinsFollow the corresponding aa. (internal intercostal and musculophrenic vv.)

Slide35

Nerves of

Thoracic Wall

Anterior

rami

of thoracic spinal nerves1‐11 intercostal nerves1‐6 end within the intercostal spaces7‐9 pass anterior deep to the costal cartilage to reach the abdominal wall10‐11 continue anteriorly to the abdominal wall12 subcostal nerveIn the abdominal wall

Slide36

Branches

of the Intercostal

Nerves

Rami communicantsCollateral branchLateral cutaneous branch1st ‐ part of the brachial plexusIntercostobrachial nerve (2nd)Referral pain in coronary artery diseaseAnterior cutaneous branchMuscular branchesPleural sensory branchesPeritoneal sensory branches (6‐11)

Slide37

Surface

Anatomy