1. Thoracic Cage

2. A. Thoracic Cage- What does it include? Ribs Thoracic Vertebrae Sternum Costal Cartilages

3. B. What does it do? Supports the pectoral girdle and upper limbs Functions in breathing Protects thoracic and upper abdominal organs Provides attachment for muscles of neck, back & shoulder

4. C. Ribs Normally, there are 12 pairs of ribs that attach to the thoracic vertebrae The first seven pairs of ribs are true (or vertebrosternal) ribs that join the sternum directly by their costal cartilages

5. Ribs (cont’d) The remaining 5 pairs are false ribs The first three pairs of these are vertebrochondral ribs The last two pairs are floating ribs

7. Features of a Typical Rib Head Neck Tubercle Shaft Costal groove Anterior (sternal) end

8. Structure of a Typical True Rib Bowed, flat bone consisting of a head, neck, tubercle, and shaft Figure 7.20a

9. Ribs (cont’d) The head articulates with the vertebrae above it The tubercle articulates with the transverse process of the thoracic vertebrae

10. Structure of a Typical True Rib Figure 7.20b

11. D. Sternum The sternum (breastbone) is located along the anterior midline of the thoracic cage It consists of an upper manubrium, middle body, and lower xiphoid process

13. Pectoral Girdle

15. Pectoral Girdle (shoulder girdle) A. Makes an incomplete ring B. Supports the upper limbs and provides attachment for muscles C. Made up of 2 scapulae and 2 clavicles

16. Pectoral Girdles (Shoulder Girdles) Figure 7.22a

17. C. Clavicles (collarbones) Elongated S-shaped bones Located at base of the neck Function: brace the scapulae (help hold shoulders in place)

19. D. Scapulae (shoulder blades) Flat, triangular bones on either side of the upper back A spine divides the scapula into unequal portions

20. Scapulae (cont’d) The spine leads to the acromion process (articulates with the clavicle) and the coracoid process (provides attachments for limb and chest muscles) The glenoid cavity articulates with the head of the humerus