Thorax.pptx

Thorax Slides from Snell's Anatomy.

1. Thorax Dr. Aliza Moin

2. Surface Anatomy

3. Thorax The thorax (or chest) is the region of the body between the neck and the abdomen SHAPE Flattened in front and behind Rounded at the sides

4. Thoracic cage Boundaries Vertebral column behind Ribs and intercostal spaces on either side Sternum and costal cartilages in front Communications Superiorly communicates with neck Inferiorly separated from viscera by diaphragm

5. Thoracic cavity The cavity of the thorax can be divided into a Median partition, called the mediastinum laterally place pleurae and lungs

6. Thoracic Wall

7. Structure of the Thoracic Wall The thoracic wall is formed posteriorly -- vertebral column anteriorly -- sternum and costal cartilages laterally -- ribs and intercostal spaces superiorly -- suprapleural membrane Inferiorly -- the diaphragm

8. Bones Of Thorax

9. STERNUM Location -- sternum lies in the midline of the anterior chest wall Shape – flat bone Parts Manubrium Body of sternum Xiphoid process

10. Manubrium It makes the upper part of the sternum Location : opposite the 3 rd and 4 th thoracic vertebrae Articulation Manubrium articulates with 1. body of the sternum at the manubriosternal joint 2. clavicles 3. 1st costal cartilage and the upper part of the 2nd costal cartilages.

11. Body of the sternum It articulates with above with the manubrium at the manubriosternal joint below with the xiphoid process at the xiphisternal joint. On each side it articulates with the 2nd to the 7th costal cartilages

12. Xiphoid process It is a thin plate of cartilage making the lower most part of sternum It ossifies at its proximal end during adult life. No ribs or costal cartilages are attached to it.

13. Sternal angle – Angle of Louis sternal angle formed by the articulation of the manubrium with the body of the sternum, can be recognized by the presence of a transverse ridge on the anterior aspect of the sternum This ridge lies at the level of the 2nd costal cartilage importance all costal cartilages and ribs are counted from this point. The sternal angle lies opposite the intervertebral disc between the 4th and 5th thoracic vertebrae.

14. RIBS There are 12 pairs of ribs. All Ribs are attached posteriorly to the thoracic vertebrae The ribs are divided into three categories: True ribs False ribs Floating ribs

15. True ribs The upper seven pairs are attached anteriorly to the sternum by their costal cartilages

16. False ribs The 8th, 9th, and 10th pairs of ribs are attached anteriorly to each other and to the 7th rib by means of their costal cartilages and small synovial joints

17. The 11th and 12th pairs have no anterior attachment

18. Typical Rib A typical rib is a long, twisted, flat bone . It has two borders superior border -- rounded, smooth inferior border -- sharp, thin. The anterior end of each rib is attached to the corresponding costal cartilage

19. Parts of typical Rib Head Neck Tubercle Shaft angle

20. Head The head has two facets. These articulate with 1. the numerically corresponding vertebral body 2. vertebra immediately above

21. Tubercle A prominence on the outer surface of the rib at the junction of the neck with the shaft. It has a facet for articulation with the transverse process of the numerically corresponding vertebrae.

22. Neck a constricted portion situated between the head and the tubercle

23. Shaft shaft is thin and flattened and twisted. Its inferior border has the costal groove. This accommodates the intercostal vessels and nerve

24. Atypical Rib 1st, 2nd, and 10th–12th The 1st rib is important clinically because of its close relationship to the lower nerves of the brachial plexus and the This rib is small and flattened

25. Typical and Atypical Ribs

26. Costal Cartilages Costal cartilages are bars of cartilage connecting the upper seven ribs to the lateral edge of the sternum 8th, 9th, and 10th ribs to the cartilage immediately above cartilages of the 11th and 12th ribs end in the abdominal Musculature Function : They contribute significantly to the elasticity and mobility of the thoracic walls.

27. Joints of the Chest Wall

28. Joints Of The Manubrium Manubriosternal joint is a cartilaginous joint between the manubrium and the body of the sternum. A small amount of angular movement is possible during respiration.

29. Xiphisternal joint cartilaginous joint between the xiphoid process (cartilage) and the body of the sternum. The xiphoid process usually fuses with the body of the sternum during middle age

30. Joints of the Ribs The Joints of the Heads of the Ribs 1st rib and the three lowest ribs have a single synovial joint with their corresponding vertebral body. For the 2nd to 9th ribs , the head articulates by means of a synovial joint with the corresponding vertebral body and that of the vertebra above it .

31. Joints of the Tubercles of the Ribs The tubercle of a rib articulates by means of a synovial joint with the transverse process of the corresponding vertebra This joint is absent on the 11th and 12th ribs

32. Joints of the Ribs and Costal Cartilages These joints are cartilaginous joints. No movement is possible.

33. Joints of the Costal Cartilages with the Sternum The 1st costal cartilages articulate with the manubrium, by cartilaginous joints that permit no movement. The 2nd to 7th costal cartilages articulate with the lateral border of the sternum by synovial joints . 6th, 7th, 8th, 9th, and 10th costal cartilages articulate with one another along their borders by small synovial joints. The cartilages of the 11th and 12th ribs are embedded in the abdominal musculature

34. Thank you