The human skeleton consists of the axial skeleton and appendicular skeleton. The axial skeleton includes the skull, vertebral column, ribs, and sternum. The skull is made up of 22 bones that form the cranium and facial bones. The vertebral column is divided into 5 regions - cervical, thoracic, lumbar, sacral, and coccyx. It provides structure and protection for the spinal cord. The appendicular skeleton includes the pectoral and pelvic girdles and their limb bones.

1. The human skeleton

2. Axial Skeleton
Includes:
1. Skull
2. Vertebral column
3. Ribs
4. Sternum
Appendicular
skeleton
Includes:
1. Girdles – Pectoral and Pelvic
2. Limb Bones – Fore limb and
Hind limb
https://askabiologist.asu.edu/sites/default/files/SkeletonViewer/SkeletonViewer.swf

3. The Skull
Cranium:
Consists of 8 flat bones joined together by immovable
joints called sutures.
Surrounds and protects the brain.

4. The bones of the cranium:
 Frontal Bone (1)

5.  2. Parietal Bones (2)

6.  – the “back” of the
head
 3. Occipital Bone (1)

7.  4. Temporal Bones (2)

8.  Sphenoid Bone (1)

9.  Ethmoid Bone (1)

10. There is a large opening at the base of the skull called
the FORAMEN MAGNUM through which the spinal
cord passes

11. On either side of the foramen magnum is a projection or
condyle which articulate with the first vertebra (called the
ATLAS) to give the nodding movement of the head

12. Facial bones:
15 facial bones.
Irregular bones that include: cheek nasal , temple and
upper and lower jaw bones.
The only movable bone is the lower jaw.
Mandible- Lower Jaw

13.  The upper and lower jaws bear the sockets for the
32 permanent teeth.
 The human dental formula is: 2.1.2.3

14. The vertebrate column
The vertebral columns is divided into 5 regions:
 Cervical (neck) region
Thoracic region (chest)
 Lumbar region (lower back)
Sacral region
 Coccyx

15. Cervical (neck) region
Consisting of 7 vertebrae.
 1st vertebra  Atlas
 2nd vertebra  Axis

16. Thoracic region (chest)
 12 vertebrae each of which bears a pair of ribs

17. Lumbar region (lower back)
The largest vertebrae as they carry the weight of the body

18. Sacral region
 Consist of 5 fused vertebrae forming a bone called the sacrum.

19. Coccyx
 Made up of 4 infused bones

20. Curves of a spine
Four curves:
 The cervical and lumbar regions curving FOWARD
 The thoracic and sacral regions curve BACKWARD

21. FUNCTIONS OF VERTEBRAL COLUMN
Supports the skull
Surrounds and protects the spinal cord.
Provides attachment for ribs, girdles, and back muscles
Separate vertebrae and S-shaped curvature provide flexibility
allowing humans to bend backwards, forwards and sideways.
Cartilage discs act as shock absorbers

22. RIB CAGE
 Consists of 12 thoracic vertebrae, 12 pairs of ribs and the
sternum or breastbone

23. Functions of rib cage:
 Protection of the heart and lungs
 With the help of the diaphragm and the intercostal
muscles they increase. And decrease the volume of the
thoracic cavity thereby allowing inhalation and exhalation
to take place.