Skeletal Cartilage: Hyaline

support, most abundant, collagen fibers, chondrocytes

4 types: Articular- movable joints

           Costal- connect ribs to sternum

Respiratory- skeleton of larynx; respiratory tract

Nasal- external nose

elastic fibers,

location: external ear, epiglottis

Fibrocartilage- compressible, tensile strength, collagen fibers, chondrocytes

location: menisci of knee, vertebrae

Cartilage Growth

-flexible matrix for mitosis

1. appositional- growth from outside

2. interstitial- growth from inside

calcification- calcium salts in matrix harden

Classification of bones

axial skeleton- long axis of body; skull, vertebral column, ribs, protection, support

appendicular- upper/lower limbs, girdles, locomotion

Shape of Bones

1.Long bones- have diaphyses(shaft) and 2 epiphyses(ends)

2.Short bones- cube shape, wrist, ankle

sesamoid bones- special type of short bone in tendon

3.Flat bone- thin,flat, sternum, scapula, ribs, skull

4.Irregular bones- complicated shape, hip, vertebra

5 Functions of Bones

1.Support- supports body, cradles organs

2.Protection-

3.Movement- walk, grasp

4. Mineral & Growth Factor Storage- stores minerals, calcium phosphate, insulin, proteins

5. Blood cell formation- hematopoiesis occurs in marrow cavities

Bone Structure

Bones are organs (composed of many tissues)

nervous tissue-nerves

osseous-bones

cartilage

fibrous connective-cavities

muscle/epithelial- blood vessels

Bone Structure Cont.

Bone Markings- depressions (allow passage of nerves/blood), projections (bulge out), openings

Bone Textures- external layer compact bone

inside compact bone is spongy bone

trabeculae- filled w/ bone marrow

Structure of Long Bone

Diaphyses- tubular shaft along along surrounds medullary cavity

medullary cavity in adults has fat (yellow bone marrow cavity)

Epiphyses-bones end (proximal/distal)

compact bone-exterior

spongy bone-interior (hyaline/articular)

epiphyseal line

epiphyseal plate- hyaline cartilage lengthens bone

metaphysis (diaphyses/epiphyses meet)

Structure of Long Bone cont.

periosteum- external white double layer membrane

outer layer (fibrous)

inner (osteogenic)- osteoblasts (bone forming) & osteoclasts (bone destroyers)

nutrient foramen- allows entrance of nerve fibers, lymphatic vessels, blood vessels

Sharpeys fibers- secure periosteum to bone

Endosteum- connective tissue covers internal bone surfaces,covers spongy bone, lines compact bone 

Structure of Short, Irregular, and Flat bones

-no shaft

-no epiphyses

-periosteum covers compact bone

-endosteum covers spongy bone

-bone marrow

-diploe(spongy bone in flat bones)

Location of Hematopoietic Tissue in Bones

red marrow- Hematopoietic tissue

Location: spongy bone of long bones, diploe of flat bones

infants; medullary cavity, spongy bone

adults; spongy bone, femur, humerus

Anatomy of Bone

Four cell types: each has matrix

osteogenic- mitotic stem cell in periosteum/endosteum

 osteoblasts

osteocytes

osteoclasts

Compact Bone(amellar)

Osteon/Haversian system- structural unit for compact bone, hollow tubes(lamella) with alternating collagen fiber

Central/Haversian canal- core contains blood vessels/ nerve fibers

Volkmann's canal- connect blood/nerve supply to canals

osteocytes- in lacunae

Compact Bone Cont

canaliculi- connect lacunae to central canal; tie osteocytes together

osteocytes- maintain bone matrix, repairs

Interstitial lamellae- fill gaps between osteons

 Circumferential lamellae- extend around diaphyses, resist twisting

Spongy Bone

trabeculae- help resist stress, irregular lamellae/osteocytes

no osteon

nutrients diffuse through canaliculi

Chemical Composition of Bone

Organic components (cells)

osteoid- organic part of matrix

ground substance

collagen fibers

sacrificial bonds(between collagen fibers provide resilience)

Inorganic (mineral salts) calcium phosphates(hardness)