BIOMECHANICS OF THORAX.pptx thorax and chest wall

thorax and chest wall

1. BIOMECHANICS OF THORAX

2. Contents GENERAL STRUCTURE: Rib Cage: Sternum Thoracic vertebrae Ribs KINEMATICS Ribs and manubriosternum Ribs and thoracic vertebrae MUSCLES ASSOCIATED WITH RIB CAGE Primary muscles of ventilation Secondary muscles of ventilation PATHO-MECHANICS

3. Introduction The thorax , commonly known as the chest, is a complex anatomical structure that plays a critical role in respiration, protection of vital organs, and postural stability . It consists of the rib cage, sternum, thoracic spine, and associated muscles , all working together to maintain both structural support and dynamic movement .

4. Function of thorax protection of vital organs Helps for ventilation Provide base for muscle attachment

5. Component of Thorax Consists of : Ribs Thoracic vertebrae Sternum

6. 1.Sternum

7. 2. Ribs

8. Structure of a Typical Rib

9. 3.Vertebra There are 12 thoracic vertebra 6 coastal articulation 4 on body 2 on transverse process Each thoracic vertebra (T1–T12) has six costal articulations (rib joints) for rib attachment. These are divided into: Four articulations on the vertebral body (Costovertebral joints) Two articulations on the transverse process (Costotransverse joints)

10. Thoracic Vertebrae

11. Articulation of thorax and chest wall

12. Manubriosternal Joint Place where manubrium attach to the sternum Synchondrosis joint- Fibrocartilagenous disc Present in between the bone and articular cartilage is covered by the hyaline cartilage. these joint similar to symphisis pubic joint in pelvis. later in 45-50 these joint will be ossify

13. Xiphisternal Joint where sternum and xiphoid meets similar like manubrio sternal joint

14. Costovertebral joint synovial joint Ribs meet the vertebral body articulation happens with head of the ribs with 2 adjuacent vertebral body and also disc in between

15. Ribs your having superior and inferior articulation

16. There are 2 types of vertebra 1. Typical CV Joint - Ribs 2 to 9 form typical CV Joint 2.Atypical CV Joint - Ribs 1,10,11,12 form atypical

17. superior facet- inferior facet of T 2 vertebra inferior facet-superior facet of T3 vertebra

18. ligamnet of CV Joint Radiate ligamnet : radiate ligament present with in the capsule with 3 bands superior, intermediate and inferior Inetrroseouss ligament: creast of the rib to annular fibrosis of disc

19. Atypical CV joint Here it is more mobile Ribs articulate with only one vertebra radiate ligament is present and interoseous ligament is absent Ribs 1,10,11,12 forms atypical cv joint

20. Costotransvere joint Transverse process of the vetebra+ribs Synovial joint with capsule around it Articultion happens B/W tubercle of the rib and trasverse process oof the vetebra

21. In total there is 10 costo trasvere articulation These can be divided into T1 to T6 The facet presnt on the transverse process are concave and tubercle resent in the ribs are convex in nature They allow some amount of rotation T7 to T10 the articulating surface are falt which allow gliding motion

22. ligaments 1.Costo transverse ligament: neck of thr rib to transverse process of same level

23. 2.Lateral constotransverse ligament:lateral portion of coastal tubercle to tip of the transverse process of same level

24. 3.superior costotransverse ligament: creast of the neck of the rib to inferior border of the transverse process of vertebra above

25. costochondral joint costo-cartilage chondral-rib articulation B/W the cartilage and ribs is costochondral articulation it happen from rib 1 to rib 10 synchondrosis articulation present anterolaterally in this outerlayer of bone and cartilage fuse together and gives stability

26. Chondrosternal joint it is the articulation B/W the cartilage and the sternum it is synovial joint it has capsule around them and they have ligament the coatal cartilage 1-7 articulate with sternum anteriorly out of these 7 the 1,6,7 are synchondrosis joint articulation happes on the lateral facet 2-5 are synovial joint where joint capsule is continues with periosteium along with help of ligament

27. ligaments anterior and posterio sternocoastal ligament coastosternal ligament coastoxiphoid ligament

28. Inter-chondral joint At the inter chondral we have coastal cartilage of the ribs 7-10 which articulate with each other immediately above them ribs 8to 10 join the sternum only through these these are the synovial joint with capsule and interchondral ligament

29. Difference Between Neonate and Adult Lungs (Based on Provided Text Only)

30. KINEMATICS

31. Dimensions of thorax Expansion of thorax take place in three dimensions: Anterio -posterior (A-P) Transverse Vertical

32. Movement of the rib cage is a combination of geometry governed by Angle of articulation Movement of Manubriosternum Elasticity of the Costal cartilage

33. Single Axis of the motion It is believed that CV and CT joints are mechanically interlinked Single axis passing through the centre both joints Axis of upper ribs lies close to frontal plane (allows motion in sagittal plane) Axis of lower ribs lies close to sagittal plane (allows motion in frontal plane)

34. First rib: ~ Anteriorly : Thicker anterior articulation Costal cartilage is stiffer than the others 1 st chondrosternal joint is synchondrosis Limit mobility Posteriorly: CV joint has only one facet Increase mobility

35. Movement of Upper ribs Take place at anterior aspect of ribs at coronal axis Costal cartilage become more horizontal Ribs pushes sternum ventrally and superiorly Excursion of manubrium is less than the body 1 st rib has shortest length Length increase caudally till 7th rib This discrepancy cause movement at MS joint

36. Movement of lower ribs Elevation occurs about axis of motion lying nearly in the sagittal plane Have more angled shape (obliquity increases 15t-10t") Indirect attachment anteriorly to the sternum These factors allow the lower ribs more motion at the lateral aspect of the rib cage Increase the transverse diameter, (BUCKET HANDLE)

37. Movements of thoracic vertebrae Depends up on the orientation of the zygoepiphyseal (ZP) joints orientation Orientation of ZP joints are in 20* off the frontal plane Thoracic facets

38. kinetics And under this we will talk about the internal intercoastal external intercoastal Para sternal fibers subcoastal

39. internal and external inter coastal

40. scalenes c3to c7 origin 1st and 2nd rib parasternal muscle

41. Primary muscles: Recruited for quite ventilation Diaphragm External intercostal Sclaene These muscle promote inspiration Expiration is a passive process

42. Diaphragm Accounts for 70-80% of inspiration during quite breathing Circular set of muscles arises from: ~ Sternum ~ Costal cartilage ~ Ribs ~ Vertebral bodies

43. Intercostals External and internal intercostals Only parasternal portion are considered as primary muscles of ventilation Sub costal group of muscles Connects adjacent ribs to one another

44. Accessory muscles of ventilation Attaches the rib cage to shoulder girdle, head, vertrbral column, or pelvis Assist with inspiration or expiration in situation of stress When trunk is stabilized, they move: Vertebral column Arm head