Skeletal

osteoblasts

bone bulding cells, synthesize extacellular matrix of bone tissue

most abundant mineral salt

calcium phosphate. can be fluoride, potassium, magnesium.

2. growth of the cartilage

a) inerstitial growth-chondroblasts then mature into chondrocyes allowing for growth in length. b) appositional growth- perichondrium secrets matrix, creating chondroblasts to condrocytes allowing growth in width.

diaphysis

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ephiphysis

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histology of bone tissue

4 types are present in done tissue. osteogenic cells, osteoblasts, osteocyes, and osteoclasts

bone deposition

addition of minerals and collagen fibers to bone by osteoblasts

appendicular skeleton

appendages and girdles

movement facilitation

assist muscles to produce movement of body parts

osteons

basic unit, contain blood vessels, nerves, osteoytes, and matrix

hemopoiesis

blood cell production; occurs in red marrow

osteoporosis

bone disorder; done resoprtion outpaces bone deposition

axial skeletal

bones of the midline

haversian canal

center os osteon; contains nerves and vessels

osteons

central(haversian) canal with cocentrically arranged lamellae, lacunae, osteocytes, and canaliculi.

clavicle

collar bone

spongy bone

contains all structures of compact bone EXCEPT osteons

collagen fiber

contribute to tensile strength(flexibility)

periosteum

covering of the bone

mineral salts

deposited and crystalize in the framework formed by the collagen fibers of the extracellular matrix; contribute to hardness of bone.

structure of long bone

diaphysis, epiphysis,metaphysis, articular cartilage, periosteum, medullary cavity, endosteum

pelvic/hip gridle

each side made of three bones that meet at the acetabulum and join at the pubic symphasis. Illium- largest Ishium-posterior and inferior Pubis-anterior inferior

5. secondary ossification center

epiphyseal artery enters the epiphyses( around birth) bone formation only spongy bone.

metaphysis

epiphyseal growth plate

factors affecting bone growht and remodeling

exercise-increases process of osteoblasts sedentary-slows process of bone formation diet- VA-stimulates osteoblasts. VC- synthesis collagen. VD-build bone. hormones. PTH decreases calcium in bone; calcitonin increases calcium, increases osteoblasts

canaliculi

extensions from osteocyte (radiating canals)

3) formation of trabeculae

extracellular matrix forms and develops into trabeculae which fuse together to form spongy bone

epiphyseal and metaphyseal

follow named artery

nutrient veins

follow named artery

nerves

follow vessles into bone and periosteum where they sense damage and trasmit pain messages

intramembranous ossification

formation fo bone directly from or within fibrous connective tissue. forms flat bones of the skull and mandible

endochondral ossification

formation of bone from hyaline cartilage models

1) development of occification center

forms from mesenchymal cells when they convert to osteoblasts and lay down matrix.

function of spongy bone

forms interior structure of shorts, flat, and irregular bones as well as the epiphyses of long bone

Skeletal System

framework of bones and cartilage that protects our organs and allows us to move

medullary cavity

hollow part of the diaphysis; bone marrow

6. articular cartilage and epiphyseal plate

hyaline cartilage covering epophyses becoming articular cartilage; epiphyseal plat is between epiphysis and diaphysis.

osteomalacia

inadequate calcification due to Viatimin d deficiency

endosteum

inside the medullary cavity

bone formation

intramembranous ossification and endochondral ossification

clacification

is initiated by bone building cells called osteoblasts

types of bones

long. short. flat. irregular. sesamoid.

trabeculae

makes bone lighter and is sometimes filled with red bone marrow. oriented along lines of stress; helps bones resist stresses without breaking.

2) calcification

matrix surrounds the cell, then calcifies as osteoblasts becomes osteocytes

osteocytes

mature bone cells, enchance nutrients and waste with the blood

1. cartilage model

mesenchymal cells develop into chondroblasts which then secretes matrix that forms hyaline cartilage periosteum then covers the outside.

3. primary ossification

nutrient artery penetrates perichondrium and catilage about midrang. perichondrium stiumulates osteoblasts to matrix over calcified cartilage, forming trabeculae.

venous supply

nutrient veins, epiphyseals and metaphyseal, nerves.

bone remodeling

ongoing replacement of old bone tissue by new bone tissue

4. medullary cavity

osteoclasts break down some newly formed trabeculae causign a cavity in the diaphysis most of the wall becomes compact bone.

articular cartilage

perforating fibers, prevent friction

4) development of periosteum

periphery of spongy bone forms then eventually is replaced by compact bone; spongy bone is left in the center

triglyceride storage

potential energy reserve

lamellae

produced around osteocytes (hard rings)

support

provides attachment sites for muscles and supports soft tissue

protection

provides bony covering for many of the body organs

nutrient artery

provides nutrients for osteocytes

osteoclasts

releases enzymes that digest the mineral components of bone matrix(resorption); regulate blood calcium level. break down bone tissue.

bone resportion

removal of minerals and collagen fibers from bone by osteoclasts

compact bone

resists the stress produced by weight and movement. components of compact bone are arranged into repeating structural units called osteons or haversian systems.

pectoral/ shoulder bone

scapula, clavicle

lacunae

space that contains osteocytes

scapula

spine-posterios gelnoid fossa- articulates with head of humerus acromion-superior; high point where scapula and clavicle articulate coracoid-anterior and lateral

storage

stores and releases minerals to maintain homeostasis

epiphyseal artery

supplies marrow and osteocells

periosteal arteries

supply compact bone

functions

support, protection, movement facilitation, storage, hemopoiesis, and triglyceride storage.

extracellular matrix

surround widely separated cells. 25% water, 25% collagen fibers, 50% crystallized mineral salts

bone formation (osteogenesis: ossification)

to grown/generate. 1.formation of bone in an embryo. 2.growth of bones until adulthood. 3.remodeling the bone. 4. repairing of fractures

balance must exist between osteoclasts and osteoblast

too much new tissue formed causes bone to be abnormally thick and heavy; excessive loss of calcium weakens the bone as in osteoporosis; may become too flexible, as in rickets and osteomalacia(lack of Vitamin D)

osteogenic cells

undergo cell division, the resulting cells devlop into osteoblasts