Basic human anatomy. axial Lecture 2.pdf

axial anatomy

1. AXIAL SKELETAL SYSTEM
Muthee Daniel

2. The Axial Skeleton
•Overview:
•-Central axis of the skeleton.
•-Protects vital organs like the brain, heart, and
lungs.
•-Includes the skull, vertebral column, and
thoracic cage.

3. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

4. Bone Classifications: Types of Bones
•Classification of bones by shape:
•-Long Bones: Found in limbs (e.g., femur,
humerus).
•-Short Bones: Cube-shaped (e.g., wrist bones).
•-Flat Bones: Thin and protective (e.g., skull
bones).
•-Irregular Bones: Complex shapes (e.g.,
vertebrae).
•-Sesamoid Bones: Embedded in tendons (e.g.,
patella).

5. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

6. Bone Classifications: Surface Markings
•Functions of surface markings:
•-Depressions and Openings: Form pathways
for blood vessels and nerves.
•* Example: Foramen magnum in the skull.
•-Processes: Attachments for tendons,
ligaments, or joints.
•* Example: Condyles, tubercles, and spines.

7. https://youtu.be/z8_hFSQKXm8
References: Tortora's Principles of Anatomy and Physiology – Chapter 7

8. The Skull: Structure and Functions
•Key Features:
•-22 bones grouped into:
•* Cranial Bones (8): Form the braincase (e.g.,
frontal, parietal).
•* Facial Bones (14): Shape the face (e.g., maxilla,
mandible).
•-Foramina: Allow passage of nerves and blood
vessels.
•-Functions: Protects the brain and supports
sensory organs.

9. The Vertebral Column: Overview
•Structure:
•-26 vertebrae organized into regions:
•* Cervical (7): Neck region.
•* Thoracic (12): Rib attachments.
•* Lumbar (5): Lower back.
•* Sacrum (5 fused): Base of the spine.
•* Coccyx (4 fused): Tailbone.
•-Supports the head and body weight.

10. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

11. Intervertebral Discs
•Components:
•-Annulus Fibrosus: Outer fibrocartilage ring.
•-Nucleus Pulposus: Gel-like core.
•Functions:
•-Absorbs shock.
•-Facilitates movement and flexibility of the
spine.

12. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

13. The Thoracic Cage: Sternum and Ribs
•Components:
•-Sternum: Divided into three parts:
•* Manubrium, Body, Xiphoid Process.
•-Ribs: 12 pairs:
•* True Ribs (1–7): Directly attach to sternum.
•* False Ribs (8–10): Indirect attachment.
•* Floating Ribs (11–12): No anterior
attachment.

14. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

15. The Thoracic Cage: Functions
•Key Roles:
•-Protects the heart and lungs.
•-Supports the shoulder girdle and upper
limbs.
•-Provides attachment points for muscles
involved in breathing.

16. Disorders of the Axial Skeleton
•Common Conditions:
•-Herniated Disc: Nucleus pulposusprotrudes,
compressing nerves.
•-Abnormal Spinal Curvatures:
•* Scoliosis: Lateral curvature.-Congenital,chronic
sciatica,paralysis
•* Kyphosis: Excessive thoracic curve-TB of spine, Osteoporosis
in women
•* Lordosis: Excessive lumbar curve-Increasedweightof
abdomen
•-SpinaBifida: Incomplete vertebral fusion
(congenital).

17. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

18. References: Tortora's Principles of Anatomy and Physiology – Chapter 7

19. Functions of the Axial Skeleton
•Summary of Key Roles:
•-Support: Framework for the body.
•-Protection: Shields vital organs like the brain,
heart, and lungs.
•-Movement: Provides attachment for
muscles.
•-Hematopoiesis: Certain bones produce blood
cells.

20. •Long Bone?
•Short Bone?
•Functionsof surfacemarkings?
•Functionof skull?
•How manybonesin Vertebralcolumn?
•Segmentsof vertebralcolumn? And numberof
bonesin eachsegment.
•Spinalcurvaturesdisorders?