MINERALIZED TISSUES

MESENCHYME

FIBROBLAST SCLEROBLAST MYOBLAST

FIBROCYTEMYOCYTES

ODONTOBLAST CHONDROBLAST OSTEOBLAST

DENTIN CHONDROCYTESOSTEOCYTES

TEETH CARTILAGES BONE

Function Of Bones Support Protection Movement Mineral storage Hemopoeisis/hematopoiesis Leverage for locomotion

➲Osteology – study of structure, function and composition of bones

Chondrology - study of structure, function and composition of cartilges

Gross Anatomy of BonesI. Compact Bones

Long BonesDiaphysis-tubular part

Epiphyses-bone ends

Epiphyseal Plate

• Blood Vessel-with nutrient arteries and veins

• Medullary cavity-marrow cavity of bones

MembranePeriosteum

-covers the entire outer surface of each bone except in epiphyses

Endosteum - innermost covering of bones

Chemical Composition of Bones

1. Organic components Collagen fibers CHON Polyssacharides2. Inorganic components calcium phosphate calcium carbonate Hydroxypatite ions

Microscopic anatomy of bones

The haversian system

Bone DevelopmentOSSIFICATION – process of bone

development1. Intramembranous ossification

- direct bone development of membrane

bones

2.Endochondral ossification - development of bones

preceeded by cartilages

Classification of Bones1. Long Bones Ex. femur, humerus

2. Short Bones Ex. trapezoid

3. Flat Bones Ex. Sternum, ribs

4. Irregular Bones Ex. Hip bones, vertebrae

TYPES OF BONES : (OSTEOGENESIS)

1. Compact Bone (Lamellar Bone)- hard bone matrix – CaCO3,CaPO4,OH)

- long bones

2. Spongy Bone (Cancelous Bone)- consist of bony trabecullae and bone marrow- trabeculae – beams,bars,rods

- irregularly arranged lamellae without haversian canals

BONE MARROW

Occupies cavities between trabellae Yellow marrow – a reticulum of

connective tissue fibers that support blood vessels, nerve fibers, adipose tissues

Red Marrow – (Hemopoietic Bone) - site of RBC and Some type of

WBC production- ex. Flat bones

3.ACELLAR BONES (ASPIDIN)

formed by blastema (mesenchymal cells w/c differentiates into tissues)

Develop through ossification Bone deposited directly within the membranous

blastema without being preceeded by cartilages (intramembranous)

May be compact or spongy,lamellar or non-lamellar, no haversian canals

Ex. Lower jaw, skull, pectoral girdles,dentin, dermal bones of teleost,apodans

4. MEMBRANE BONE

Bones formed in scales of modern fishes

No canaliculi Ex. Scales of fishes,cementum of

teeth

5. Replacement Bones

Arise from pre-existing cartilages Soft bones Endochondral ossification Ex. Fontannels, tetrapod bones with

cartilaginous diaphysis and 2 epiphysis, epiphyseal plate

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II. Cartilage

- specialized connective tissue in which fibers are laid down along the lines of stress in long, parallel arrays firm and flexible chondrocytes - cartilage cells that live within spaces (lacunae) within cartilage matrix

-CHONDRIFICATION – chondroblast- chondrocytes

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Cartilage

TYPES OF CARTILAGESBASIS HYALINE ELASTIC FIBRO-

CARTILAGE

1.Matrix Fine collagenousfibers

Collagenous,elastic fibers

Dense collagenous

2. Function

Cover and protect bones,support

Flexible strength

Withstand tension & compression

3. Location

Joints, trachea,costal ribs

Ears,nose, larynx,audi-tory canal

Vertebral discs,pubic sysmphysis

4. THE CALCIFIED CARTILAGE

The cartilages replaced by bones Ex. Jaw, fins of sharks, fontannels of

the fetal human skull

III. DENTIN

Developed from the odontoblast Odontoblast are not trapped in

lacunae during osteogenesis – retreat as dentin deposits

Canaliculi – dentibal tubules Ex. Enameloid of placoid scales,

dentin of the teeth

IV. ENAMEL

Developed from ameloblasts Teeth – important for digestion

V. BONE REMODELING

PRESKELETAL MESENCHYMAL BLASTEMA

CARTILAGES

RESORPTION OF Ca Membrane Bone

Replacement Bones

CONTINUAL RESORPTION AND REMODELING

PARATHORMONE AND CALCITONIN

The hormones that influence or regulates the withdrawal of calcium to maintain calcification

OSTEOBLAST – developing bone cells

OSTEOCLAST – bone destructing cells

OSTEOCYTES – bone-building cells

VI. CONNECTIVE TISSUES OF BONES

1. TENDON

2. LIGAMENTS

3. CARTILAGES

Phases of Healing of Fractures

Hematoma Formation

Fibrocartilaginous Callus Formation

Body Callus Formation

Bone Remodeling

FRACTURE HEALING

HEMATOMA FORMATION

CARTILAGINOUS CALLUS

REMODELINGBONY CALLUS

& CARTILAGI-NOUS

MEMBRANE

NORMAL

BONE

The Articular System

Joints/articulation-places where the rigid elements of the

skeleton meet.

TYPES OF JOINTS ACCORDING TO FUNCTION:

1. Synarthroses-fixed or immovable joints

2. Amphiarthroses-slightly movable joints

3. Diarthroses-freely movable joints

TYPES OF JOINTS ACCORDING TO STRUCTURE:

1. FIBROUS JOINTSa. structures-minimal connected tissueb. syndesmoses-connected by ligamentsc. gamphoses-peg-in-socket joint

2. CARTILAGINOUS JOINTSa. synchondrosis-hyaline cartilageb.symphyses-fibrocartilage

3. SYNOVIAL JOINTS-most movable joints of the body

-diarthoroses

Features of Synovial joints

1. Articular cartilage2. Joint cavity/ synovial cavity3. Articular Capsule

2 LAYERS:a. fibrous capsule

-strengthens joint so that bones are not pulled apart

b. synovial membrane-cover enternal joint surfaces

4. Synovial fluid-a filtrate of blood which contains glycoproteins

5. Reinforgang ligaments-thickened parts of fibrous capsule itselfa. Extracapsular ligamentb. Intracapsular ligament

6. Nerves and Blood vessels

SYNOVIAL MEMBRANE

Types of Synovial joints

1. Plane joints-nonaxial joint

2. Hinge joints-uniaxial joint(flexible)

3. Pivot joints- rotatory, uniaxial joint

4. Condyloid joints- biaxial joint

5. Ball and Socket joints-multiaxial joint

HETEROTROPIC BONES

OS CORDIS OS CLITORIDIS OS BACULUM ROSTRUM