OSTEOLOGY BONES. 21. September 201 2 Friday. Kaan Yücel M.D., Ph.D . . INTRODUCTION TO OSTEOLOGY. Osteology ( Gk , osteon, bone, logos, science) branch of medicine concerned with the development and diseases of bone tissue The human skeleton 206 bones in adults .
21. September2012 Friday
Kaan Yücel M.D., Ph.D.
Osteology (Gk, osteon, bone, logos, science)
branch of medicine concerned with the development and diseases of bone tissue
The human skeleton
206 bones in adults
one of the hardest structures of the animal body
calcification of its extracellular matrix
results from the organic matter
results from their lamellous structures and tubes of inorganic calcium phosphate
colorin a fresh state
pinkish-whiteexternally, deep red within.
HISTOLOGY OF THE BONE
sparse cells surrounded by an extracellular network/matrix
secrete proteins into the matrix.
Mature bone is composed of proteins and minerals.
60% the weight of the bone mineral
Rest- water & matrix.
90% of the matrix proteins collagen1/3 of the bone weight
forms bone, cartilage, skin, and tendons.
High resolution image of cortical bone and single collagen fibril (inset)
Mineralsof the matrix
Mainlycalcium phosphate & calcium carbonate
Embedded in the protein network
Providehardness and compressive strength.
Matrix maintained by osteocytes
Haversiansystems or osteons
concentric rings of osteocytes arranged around a central blood vessel.
Principal types of bone cells
membranesurroundingthe bone tissue
provides a routeforthevasculatureandnervesupply.
participates in bone growthandrepair.
linesthe marrow cavity
active during bone growth, repair, and remodeling
covers trabeculaeof spongy bone
lines the inner surfaces of the central canals
articulating of bones participating in a synovial joint capped with articular cartilage
provides smooth, low-friction, gliding surfaces for free movement
The skeleton is composed of cartilages and bones.
The amount and kind of extracellular fibers in the matrix
depends on the type of cartilage.
Heavyweightbearing areas or areas prone to pulling forces
support soft tissues
provide a smooth, gliding surface for bone articulations at joints
enable the development and growth of long bones.
Long bones develop by replacement of hyaline cartilage plate endochondral ossification
a shaft diaphysis - two ends epiphyses
a part of the diaphysis adjacent to the epiphyses.
Diaphysisencloses the marrow cavity.
2types of bones according to histological features
compact bone &spongy (trabecular) bone
relative amount of solid matter
#&size of the spaces they contain
is supported on the summit of the vertebral column, and is of an oval shape, wider behind than in front.
It is composed of a series of flattened or irregular bones which, with one exception (the mandible), are immovably jointed together. It is divisible into two parts:
cranium, which lodges and protects the brain, consists of 8 bones
skeleton of the face,of 14
at the back and lower part of the cranium
trapezoid in shape and curved on itself.
pierced by a large oval aperture, the foramen magnum,
cranial cavity communicates with the vertebral canal
form, by their union, the sides and roof of the cranium
each bone irregularly quadrilateral in form
external surface convex, smooth
@front of the skull. Forms theforehead.
Entersinto the formation of the roofs of the orbital and nasal cavities.
at the sides and base of the skull.
consist of the pathway to the inner ear and contributes to the formation of the jaw with the mandible.
at the base of the skull in front of the temporals and basilar part of the occipital.
median portion or body, two great and two small wings extending outward from the sides of the body, and two pterygoid processes which project from it below.
supplies the bed for the pituitary gland.
exceedingly light and spongy
cubical in shape
at the anterior part of the base of the cranium
between the two orbits, at the roof of the nose
contributes to each of these cavities.
Anterior cranial fossa
occupiedbytheinferior and anterior parts of
the frontal lobes of the brain
shallowest cranial fossa
Middle cranial fossa
central part composed of the sellaturcica on the body of the sphenoid
large, depressed lateral parts on each side
Posterior cranial fossa
largest and deepest cranial fossa
formed mostly by the occipital bone
smallest & most fragile bone of the face
at the front part of the medial wall of the orbit
ZygomaticBone (Malar Bone)
small and quadrangular
at the upper and lateral part of the face
prominence of the cheek
part of the lateral wall & floor of the orbit.
zygomaticprocess of the temporal bone temporal process of the zygomaticbone
@ back part of the nasal cavity.
contributes to the walls of three cavities
floor and lateral wall of the nasal cavity
roof of the mouth
floor of the orbit.
Inferior Nasal Concha
extends horizontally along the lateral wall of the nasal cavity.
in the median plane
thin, somewhat quadrilateral in shape
forms hinder & lower part of the nasal septum.
Mandible (Lower Jaw)
largest and strongest bone of the face
serves for the reception of the lower teeth.
G. sternon, chest
The change in size is related to the fact that successive vertebrae bear increasing amounts of the body's weight as the column descends.
The vertebrae reach maximum size immediately superior to the sacrum, which transfers the weight to the pelvic girdle at the sacroiliac joints.
The vertebral column is flexible because it consists of many relatively small bones, called vertebrae (singular = vertebra), that are separated by resilient intervertebral (IV) discs.
BONES OF THE UPPER LIMB
sphericalhead of the humerus articulates with the glenoid cavity of the scapula.
surgical neck of the humerus, a common site of fracture, is the narrow part distal to the head and tubercles.
distal end of the humerus makes up the condyle of the humerus.
BONES OF THE FOREARM
The two forearm bones serve together to form the second unit of an articulated mobile strut (the first unit being the humerus), with a mobile base formed by the shoulder, that positions the hand.
Its more massive proximal end is specialized for articulation with the humerus proximally and the head of the radius laterally.
lateral and shorter of the two forearm bones.
Itsproximal end includes a short head, neck.
Proximally, the head of the radius is concave for articulation with the humerus during flexion and extension of the elbow joint.
The head also articulates with the ulna.
The shaft of the radius, in contrast to that of the ulna, gradually enlarges as it passes distally.
bones of the lower limb
THE PELVIC GRIDLE
The skeleton of the lower limb (inferior appendicular skeleton)
may be divided into two functional components:
bones of the free lower limb.
The mature hip bone (L. oscoxae) is the large, flat pelvic bone formed by the fusion of three primary bones—ilium, ischium, and pubis.
Tibia (Shine bone)
on the anteromedial side of the leg, nearly parallel to the fibula
second largest bone
anterior border of the tibia -most prominent border.
tibia & adjacent medial surface subcutaneous throughout their lengths
commonly known as the “shin”
periosteal covering and overlying skin vulnerable to bruising.
Inferiorsurface of the shaft & lateral surface of medial malleolus articulate with the talus.
Interosseous membrane unites the two leg bones.
Inferiorly, the tibia articulates with the distal end of the fibula.
posterolateral to the tibia
no function in weight-bearing
serves mainly for muscle attachment.
distal end enlarges prolonged as lateral malleolus
proximalend an enlarged head superior to a small neck.
patella (knee cap)
largest sesamoid bone in the body
embedded in the quadriceps femoris tendon.
jointbetweenthepatellaandfemursharethesamearticularcavity w/ thejointbetweenfemur & tibia
patellar ligament connects the patella to the tibia.
Bones of the foot
Tarsus (7 bones)
Metatarsus (5 bones)
Phalanges (14 phalanges)