Anatomy Lab exercise 8

Axial Skeleton

1. Lab Exercise 8 Axial Skeleton: Vertebrae, Ribs, sternum, hyoid

2. Overview of Vertebrae Vertebral column Lower vertebrae are larger than upper Intervertebral discs Fibrocartilaginous pads between vertebrae Vertebral foramen Large hole where the spinal cord passes through Body Supports the weight In contact with the disc Vertebral arch Posterior to the body Consist of two pedicles and two lamina

3. Overview of Vertebrae Pedicles Extends from the body of the vertebra to the two lateral projections Transverse processes Lamina broad flat structure between the transverse process and the dorsal spinous process Superior articular process and superior articular facet Articulates with the vertebra above Inferior articular process and inferior articular facet Articulates with the vertebra below Intervertebral foramen Hole where the spinal cord is located

4. Spinal Curvatures 4 Curvatures Cervical Convex Thoracic Concave Lumbar Convex Sacral (pelvic) Concave These allow for balance in an upright posture and provide room for the lungs and other organs

5. Cervical Vertebrae (7) C1-C7 They are the only vertebrae that have three foramina Vertebral and two transverse foramina Vertebral arteries and veins C2-C6 Bifid spinous processes Split in two C7 Vertebra prominens Spinous process that projects sharply in a posterior direction Body is less massive than the inferior vertebrae

6. Atlas vs Axis (C1&C2) Atlas (C1) Only vertebrae without a body Atlas was a titan in Greek mythology who held up the world Atlas joins with the head and allows you to shake your head ”Yes” Axis (C2) Dens Process which runs superiorly through the atlas Allows the axis to move on the atlas allowing you to rotate head to indicate “No”

7. Thoracic Vertebrae (12) T1-T12 Markings on their lateral posterior bodies Articulation points for the ribs Rib (Costal) facet Marking when just one rib is attached Demifacet Marking when two rids are attached The head of the rib attaches to the demifacet Longer spinous processes and angle more inferiorly Looks like a Giraffe

8. Lumbar Vertebrae (5) L1-L5 Do NOT have transverse foramina or rib facets Spinous process tend to be more horizontal Lumbar body is larger Carry more weight Looks similar to a Moose

9. Vertebrae Cervical vertebrae C1-C7 I eat breakfast at 07:00 AM Thoracic vertebrae T1-T12 I eat lunch at 12:00 or noon Lumbar vertebrae L1-L5 I eat dinner at 05:00 PM

10. Sacrum Large, wedge-shaped bone composed of 5 fused vertebrae Shallow, triangular bowl Transverse lines These are the fusion lines on posterior and anterior view Anterior surface The shallow depression Anterior sacral foramina The two rows of holes on the anterior surface Posterior sacral foramina The two rows of holes on the posterior surface

11. Sacrum cont.. Sacral promontory Rim on the anterior superior part of the sacrum Ala Lateral to the promontory Wing-like Articular or Auricular (ear-shaped) surfaces Lateral to the ala Each joins with the ilium to form the sacroiliac joint Helps with additional force that is applied to the sacrum

12. Sacrum Posterior View Median and lateral sacral crests Sacral canal Superior and inferior openings Superior articular processes and the superior articular facets Joins with L5 vertebra Sacral hiatus Opening at the inferior part of the sacrum

13. Coccyx “Tail bone” The terminal portion of the vertebral column 4 fused vertebrae

14. Hyoid Found at the junction of the floor of the mouth and neck The floating bone Anchored by muscles from the anterior, posterior and inferior direction Aids tongue movement and swallowing Body Located in the center of the bone Greater and Lesser Horn ( Cornu ) Greater is more posterior Lesser is more anterior

15. Ribs (12) Total of 12 paired ribs along with the sternum that makes up the thoracic cage True ribs First 7 pairs Attached to the sternum by their own cartilage False ribs Ribs 8-12 Do NOT attach to the sternum by their own cartilage Floating ribs Ribs 11 & 12 Do NOT attach to the sternum at all

16. Rib Structures Head Articulates with the body of one or more vertebrae Neck Constricted region near the head of the rib Tubercle Process near the neck and head of the rib 1-10 Articulates with the transverse process of vertebra Shaft Posterior view bending outward Angle or Costal angle Ribs 2-10 proximal bend near the head of the rib Sternal end Attaches to a costal cartilage prior to joining the sternum Costal groove Depression that runs along the inferior edge of each rib

17. Sternum Composed of 3 fused bones Manubrium Superior segment Jugular notch Depression at the top of the manubrium Clavicular notches Lateral side of the manubrium Articulation sites for the clavicles Body or Gladiolus Main portion of the sternum Sternal angle Between the body and the manubrium Costal notches Cartilage of the ribs attach Xiphoid process Narrow, bladelike part of the sternum Most inferior segment CPR- Careful

18. Thoracic Cage

19. Know For The Lab Exam Vertebrae ID the differences of each vertebrae (C/T/L) Name all significant surface features of the vertebrae Atlas vs Axis Hyoid bone Locate major features Ribs True, False, and Floating ribs # and how they differ Left form right rib Anatomical features Sternum ID the 3 different parts Significant surface features