3. BONE
Bone is made up of Osseous tissue,
cartilage, dense connective tissue,
epithelium, adipose tissue.
The entire framework of bones and
cartilages constitute the “Skeletal
System”.
4. The bones, muscles and joints
together form “Musculoskeletal
system”
The branch of medical science
concerned with the prevention or
correction of disorders of the
musculoskeletal system is called
“Orthopedics”
5. FUNCTIONS OF BONE
Support
Protection
Assists movement
Mineral storage
Hematopoesis
12. TYPES OF BONE TISSUE
Compact bone tissue
Spongy bone tissue
13.
14. MICROSCOPIC STRUCTURE OF
BONE
Bone may be Compact or Spongy.
1. Compact Bone
Strongest form of bone tissue with few
spaces.
Found beneath the periosteum.
Provides protection, support, resists the
pressure produced by weight and
movement.
15. COMPACT BONE
Few spaces, found beneath the Periostuem
Consist of:
1. The main structural unit is called
OSTEON.
2. Each Osteon consist of a CONCENTRIC
LAMELLAE arranged around CENTRAL
CANAL.
3. Radiating from lacunae are tiny
projections called CANALICULI.
16. 4. Blood vessels, nerves, lymphatic vessels
from periosteum penetrate the Compact
bone through VOLKMANN’S CANAL/
PERFORATING CANALS.
5. Arranged around the entire outer and
inner circumference of bone are
CIRCUMFERENTIAL LAMELLAE.
17. Spongy or Cancellous Bone
Makes the bone light.
Short, flat and irregularly shaped bone
contain spongy bone tissue.
Consist of lamellae arranged in irregular
pattern called TRABECULAE.
Between these Trabeculae are spaces filled
with yellow and red bone marrow.
The trabeculae consist of concentric
lamellae, lacunae and canliculi
18. HISTOLOGY OF BONE TISSUE
Called Osseous Tissue.
It contains extracellular matrix or bone
matrix which is composed of 25% water,
25% collagen fibers and 50% crystallized
mineral salts.
As these mineral salts are deposited in
the extracellular matrix, they crystallize
and the tissue hardens. This process is
known as Calcification.
19. BONE CELLS
Four types of cells:
Osteogenic cells
Osteoblasts
Osteocytes
Osteoclasts
21. DIVISIONS OF THE SKELETAL SYSTEM
The human skeleton consists of 206
named bones.
Bones of the skeleton are grouped into
two principal divisions:
I) Axial skeleton
II) Appendicular skeleton
22. I) Axial skeleton
Consists of the bones that lie around
the longitudinal axis of the human body
Skull bones, hyoid bone, ribs, sternum
and bones of the vertebral column
51. FACIAL BONES
Nasal Bones (2)
Form the bridge of the nose
Maxillae (2)
Form the upper jawbone
Form most of the hard palate
Separates the nasal cavity from the oral
cavity. Contains maxillary sinus.
54. Zygomatic Bones (2)
Commonly called cheekbones, form the
prominences of the cheeks
Lacrimal Bones (2)
Resemble finger nail in size and shape.
They are posterior to nasal bone. Form
a part of the medial wall of each orbit
55. Palatine Bones (2)
L shaped, form the posterior portion of
the hard palate, part of the floor of nasal
cavity
Inferior Nasal Conchae (2)
Form a part of the inferior lateral wall of
the nasal cavity. Helps to filter the air in
nasal cavity.
56. Vomer (1)
Roughly triangular bone, forms the
inferior portion of the nasal septum
Mandible (1)
Lower jawbone, largest and strongest
facial bone, only movable skull bone
59. THE HYOID BONE
“U” shaped, does not articulate with
any other bone. It is suspended by
ligaments and muscles.
Located in the anterior neck between
mandible and larynx.
It supports tongue, provides attachment
site for tongue muscles and muscles of
neck and pharynx.
Figure 7–12c
60. WHAT ARE THE VERTEBRAL REGIONS,
THE CURVATURES OF THE VERTEBRAL
COLUMN, AND THEIR FUNCTIONS?
61. THE VERTEBRAL COLUMN
The spine, spinal column or vertebral
column:
protects the spinal cord
supports the head and body
It is composed of series of bones called
as Vertebrae.
62. 71 cm in adult male and 61 cm in adult
female.
The adult vertebral column typically
contains 26 vertebrae.
67. PRIMARY CURVES
Thoracic and sacral curves:
are called primary curves (present
during fetal development)
SECONDARY CURVE
Lumbar and cervical curves:
are called secondary curves (appear
after birth)
69. INTERVERTEBRAL DISCS
Found between the bodies of adjacent
vertebrae from C2 to Sacrum. They are
pads of fibrocartilage.
Absorb shocks, form strong joints and
permit various movements of the
vertebral column.
76. VERTEBRAL COLUMN (REGIONS)
Cervical Region
Cervical vertebrae (C1–C7)
The atlas (C1) is the first cervical vertebra
The axis (C2) is the second cervical vertebra
Thoracic Region
Thoracic vertebrae (T1–T12)
Articulate with the ribs
Lumbar Region
Lumbar vertebrae (L1–L5)
Provide for the attachment of the large back muscles
Sacrum
The sacrum is a triangular bone formed by the union of five sacral
vertebrae (S1–S5)
Serves as a strong foundation for the pelvic girdle
Coccyx
The coccyx, like the sacrum, is triangular in shape
It is formed by the fusion of usually four coccygeal vertebrae
85. THORAX
Thoracic cage is formed by the:
Sternum
Ribs
Costal cartilages
Thoracic vertebrae
Functions to:
Enclose and protect the organs in the thoracic
cavity.
Provide support for the bones of the upper
limbs
Play a role in breathing
86. Sternum
“Breastbone” located in the center of the
thoracic wall
Consists of the manubrium, body, xiphoid
process
Ribs
Twelve pairs of ribs give structural support to
the sides of the thoracic cavity
Costal cartilages
Costal cartilages contribute to the elasticity of
the thoracic cage