1. Chapter 5 The Skeletal System Provides an internal framework for the body, protects organs by enclosure, and anchors skeletal muscles so that muscle contractions can cause movement

2. The Axial Skeleton

3. The Skull  Two sets of bones  Cranium  Facial bones  Bones are joined by sutures  Interlocking, immovable joints  Only the mandible is attached by a freely movable joint

4. The Skull

5. Bones of the Skull

6. Deviated Nasal Septum

7. Human Skull, Superior View

8. Human Skull, Inferior View

9. Paranasal Sinuses  Hollow portions of bones surrounding the nasal cavity

10. Paranasal Sinuses  Functions of paranasal sinuses  Lighten the skull  Give resonance and amplification to voice

11. Sinusitis Website

12. The Hyoid Bone  The only bone that does not articulate with another bone  Serves as a moveable base for the tongue

13. The Fetal Skull  The fetal skull is large compared to the infants total body length

14. The Fetal Skull More info More info  Fontanelles- fibrous membranes connecting the cranial bones  Allow the brain to grow  Convert to bone within 24 months after birth

15. 7 cervical vertebrae 7 cervical vertebrae C1 = Atlas; C2 = Axis C1 = Atlas; C2 = Axis 12 thoracic vertebrae, larger than the cervical vertebrae 12 thoracic vertebrae, larger than the cervical vertebrae 5 lumbar vertebrae have massive block-like bodies; sturdiest of the vertebrae 5 lumbar vertebrae have massive block-like bodies; sturdiest of the vertebrae Sacrum formed by the fusion of five vertebrae Sacrum formed by the fusion of five vertebrae Coccyx formed from the fusion of three to five tiny, irregularly shaped vertebrae, human “tailbone” Coccyx formed from the fusion of three to five tiny, irregularly shaped vertebrae, human “tailbone”

16. The Vertebral Column  Vertebrae separated by intervertebral discs  The spine has a normal curvature  Each vertebrae is given a name according to its location

17. Structure of a Typical Vertebrae

18. Three common types of abnormal spine curvatures: scoliosis, kyphosis, lordosis Three common types of abnormal spine curvatures: scoliosis, kyphosis, lordosis These abnormalities may be present at birth or result from disease, poor posture, or unequal pull on the spine These abnormalities may be present at birth or result from disease, poor posture, or unequal pull on the spine

22. Herniated Disk website

23. Sciatica

24. The Bony Thorax  Forms a cage to protect major organs

25. The Bony Thorax  Made-up of three parts  Sternum  Ribs  Thoracic vertebrae

26. The Appendicular Skeleton  Limbs (appendages)  Pectoral girdle  Pelvic girdle

27. The Pectoral (Shoulder) Girdle  Composed of two bones  Clavicle – collarbone  Scapula – shoulder blade  These bones allow the upper limb to have exceptionally free movement

28. Bones of the Shoulder Girdle

29. Bones of the Upper Limb  The arm is formed by a single bone  Humerus

30. Bones of the Upper Limb The forearm has two bones Ulna Radius

31. Bones of the Upper Limb  The hand  Carpals – wrist  Metacarpals – palm  Phalanges – fingers

32. Bones of the Pelvic Girdle  Hip bones  Composed of three pair of fused bones  Ilium  Ischium  Pubic bone  The total weight of the upper body rests on the pelvis  Protects several organs  Reproductive organs  Urinary bladder  Part of the large intestine

33. The Pelvis

34. Gender Differences of the Pelvis

35. Bones of the Lower Limbs  The thigh has one bone  Femur – thigh bone

36. Bones of the Lower Limbs  The leg has two bones  Tibia  Fibula

37. Bones of the Lower Limbs  The foot  Talus – ankle  Metatarsals – sole  Phalanges – toes