1. Bones
Dr. Sama ul Haque

2. Objectives Define Skeleton.
Differentiate between Axial and Appendicular skeleton.
Define bones with their constituents.
Enumerate their functions.
Define Cartilage.
Discuss different types of cartilage with examples.
Classify the bones on the following basis.
1. Histological or Microscopically
2. Gross Appearance or Macroscopically

3. Objectives Define Ossification and its types.
Describe developing parts of a typical long bone.
Give the arterial supply of a Mature long Bone.
What are different types of bone break.
Define terms used for describing Bony features.

4. Axial Skeleton These bones lie around the longitudinal
axis of the body.
Skull (cranium and facial bones)
Vertebral column (vertebrae and discs)
Thoracic cage (ribs and sternum)
Function:
Axial skeleton supports and protects
organs of head, neck and thorax.

5. Appendicular skeleton
Pectoral or Shoulder girdle
(clavicles and scapulae)
Upper limbs (arms)
Pelvic girdle
(Hip bones, sacrum, coccyx)
Lower limbs (legs)
Function:
Voluntary movements
Protection of delicate Structures

6. Composition of Bones Collagen: chief organic constituent (protein)
Inorganic Calcium Salts: Vitamin D essential for absorption

7. A Chemical Analysis of Bone

8. Cells
Osteoblasts: bone building, bone repairing cells in the periosteum and synthesize new matrix (Osteogenesis)
Osteocytes: osteoblast embedded within the bone matrix (mature bone cells)
Osteoclasts: cells that cause absorption of bone or
dissolve bone matrix (Osteolysis)

9. Periosteum Endosteum Dense, fibrous membrane covering bone
Contains blood vessels
Essential for bone cell survival and bone formation
Endosteum

10. Functions of Bones Shape Support Protection => Skull
=> Thoracic cage
=> Vertebral Column

11. Functions of Bones Movement => Muscles => Tendons
=> Ligaments
Locomotion:
To provide a lever system against which muscles can pull.
Weight Transmission

12. Functions of Bones Mineral Storage => Calcium => Phosphate
=> Results in maintaining Electrolyte balance
Helps in Respiration

13. Functions of Bones Blood cell formation Red Bone Marrow
 Red gelatinous mass consisting of
Haemopoietic tissue
> Ends of long bones
> Bodies of vertebrae
> Sternum
> Flat bones of skull

14. Cartilage Type of Dense connective tissue ( Cells and fibers)
Perichondrium ( Fibro-vasculo-cellular membrane)
Cells = Characterized by Rigid with flexibility and
Resilience.
Avascular
Nerves and lymphatics are absent
Cells (Chondroblasts and chondrocytes)
Matrix => Connective tissue fibers (Collagen, Elastin)

15. Types of cartilage: 3 Hyaline cartilage: flexible and resilient
Elastic cartilage: highly bendable
Fibrocartilage: resists compression and tension

16. Hyaline Cartilage Hyaline (Glass) Commonest form
Bluish white, translucent and homogenous in appearance with collagen fibers
=> Articular cartilage
=> Costal cartilage
=> Tracheal cartilage
 Ossifies to form bone in young age

17. Elastic Cartilage Yellow; Elastin fibers More elastic than hyaline
Sites
=> Pinna of the ear
=> Epiglottis
 Never ossifies

18. Fibro-cartilage White, Opaque with collagen fibers Sites
=> Intervertebral disc
=> Intra articular disc
=> Menisci
 Ossifies in old age

19. Classification of bones
Histological or Microscopically
Gross Appearance or Macroscopically

20. Compact and Spongy Bone
Histological or Microscopically
Compact and Spongy Bone

21. Compact and Spongy Bone

22. Classification of Bones According to Shape
Long Bones
Short Bones
Flat Bones
Irregular Bones
Sesamoid Bones

23. Developing parts of a typical long bone

24. Long Bones Epiphysis (Spongy): Covered with Hyaline cartilage.
Diaphysis (Compact):
Covered with Periosteum.
Medullary cavity with yellow
and red marrow.
Examples:
Femur, Tibia, Fibula, Humerus,
Ulna, Radius, Clavicle.

25. Miniature Long Bones Only one Epiphysis: Examples: Metacarpals
Metatarsals
Phalanges

26. Short Bones Cube-shaped Allows flexible movement Spongy bone
covered by
Compact bone
Examples:
Carpals & Tarsals,

27. Flat Bones Flat Plates Protect Vital Organs Examples:
Bones of Vault of
Skull
Ribs
Scapula
Sternum

28. Flat bones

29. Irregular Bones Peculiarly Shaped to provide Support and Protection
with Flexibility.
Examples:
Vertebrae
Hip bone
Bones of base
of Skull.

30. Sesamoid Bones Periosteum absent. Ossify after birth. Functions:
Resist pressure
Reduce friction
Examples:
Patella
Pisiform
Fabella

31. Ossification OR
Osteogenesis

32. CLASSIFICATION of BONES According to development:
1. Membranous = starts as fibrous membrane,
calcium gradually deposited until structure
becomes ossified  intramembranous ossification
e.g.: bones of the skull, mandible
2. Cartilagenous = starts as cartilage, gradually ossified
enchondral or intracartilagenous ossification.
e.g.: long bones

33. Developing parts of a typical long bone

34. The arterial supply of a Mature long Bone

37. Types of bone breaks
Simple: Skin is not pierced.
Compound: Skin is pierced.
Complete: Bone is broken in half
Greenstick: Incomplete break on outer arc.
Comminuted: Broken into several pieces

39. Thank you