WARM UP 1/30WARM UP 1/30

1.1. What do you call the cavities that hold osteocytes?What do you call the cavities that hold osteocytes?2.2. What are lamellae?What are lamellae?3.3. What is the long main portion of long bone called?What is the long main portion of long bone called?4.4. What does calcified mean?What does calcified mean?5.5. What are tiny radiating canals that bring nutrients What are tiny radiating canals that bring nutrients

to bone cells called? to bone cells called? 6.6. From your homework – what are 5 ways that From your homework – what are 5 ways that

increase chances of bone fractures?increase chances of bone fractures?7.7. What are 3 ways to see a bone fracture?What are 3 ways to see a bone fracture?

NOTES Ch 6 1/30NOTES Ch 6 1/30

Bone growth and strengthBone growth and strength

Grow in diameter due toGrow in diameter due to

1.1. OSTEOCLASTS – found in endosteumOSTEOCLASTS – found in endosteum

* enlarge inside of medullary * enlarge inside of medullary

cavity by eating away the wallscavity by eating away the walls

2.2. OSTEOBLASTS – found in the periosteumOSTEOBLASTS – found in the periosteum

* add new cells to increase the outside * add new cells to increase the outside

of the boneof the bone

OSSIFICATION – turning to boneOSSIFICATION – turning to bone

RESORPTION – breaking down boneRESORPTION – breaking down bone

YEARSYEARS RESULTRESULT

0-180-18 Ossification > Ossification > ResorptionResorption

Bone growBone grow

19-3519-35 Ossification = Ossification = ResorptionResorption

Bone stays Bone stays samesame

36+36+ Ossification < Ossification < ResorptionResorption

Bone becomes Bone becomes thinnerthinner

Grow in length due toGrow in length due to

EPIPHYSEAL PLATEEPIPHYSEAL PLATE Cartilage area in the epiphysisCartilage area in the epiphysis

Grows wider to make bones longerGrows wider to make bones longer

Males (0-20) Females (0-18)Males (0-20) Females (0-18) Adult – epiphyseal plate calcifiesAdult – epiphyseal plate calcifies

* X-ray – no epiphyseal plate, then done growing * X-ray – no epiphyseal plate, then done growing (can see in bones of legs or wrists)(can see in bones of legs or wrists)

Add EPIPHYSEAL PLATE to #6 on your bone diagram

Amount of growth due toAmount of growth due to

1.1. Sex hormones – estrogen and testosteroneSex hormones – estrogen and testosterone

2.2. Growth hormone – produced by pituitary Growth hormone – produced by pituitary glandgland

3.3. Physical activity – more=growthPhysical activity – more=growth

4.4. GeneticsGenetics

Bone StrengthBone Strength

Calcium makes bones strong Calcium makes bones strong Vitamin D helps your body absorb calciumVitamin D helps your body absorb calcium If you don’t have enough calcium, it comes If you don’t have enough calcium, it comes

out of your bones and makes them weakerout of your bones and makes them weaker Exercise puts pressure on bones which Exercise puts pressure on bones which

makes them strongermakes them stronger

Cartilage development at the growth plate of the long bones. (A) Normal growth plate showing

(B) Growth plate in dysplasia. The growth plate is disorganized and shows no region of reproducingchondrocytes.

NOTES Ch 6NOTES Ch 6

Bone problems and diseasesBone problems and diseases

2/22/2

DYSPLASIA - bone and cartilage disorders that affect the growth and development and result in short limbs.

In addition to physical characteristics such as short arms and legs, people with skeletal dysplasias may have many other health-related problems, such as spine disorders; cardiac defects; ear, nose and throat problems; and neurologic disability.

ACHONDROPLASIAACHONDROPLASIA

a hereditary skeletal disorder characterized by a unique form of dwarfism.

(shortness of the extremities relative to the trunk. )

The adult height in achondroplasia is usually less The adult height in achondroplasia is usually less than four feet. The extremities (legs, arms, fingers, than four feet. The extremities (legs, arms, fingers, toes) are very short (micromelia) relative to the toes) are very short (micromelia) relative to the trunk which is only slightly shortened. trunk which is only slightly shortened. Intramembraneous ossification is not affected. The Intramembraneous ossification is not affected. The head (cranial vault) is large. The root of the nose head (cranial vault) is large. The root of the nose is depressed. The skeletal deformities just noted is depressed. The skeletal deformities just noted along with normal intelligence and sexual along with normal intelligence and sexual development distinguish achondroplasia from development distinguish achondroplasia from dwarfism resulting from endocrine and nutritional dwarfism resulting from endocrine and nutritional deficiencies and other causes. deficiencies and other causes.

Vitamin D helps body to absorb Ca you eat.Vitamin D helps body to absorb Ca you eat.

RICKETS–bending of bones from weight of RICKETS–bending of bones from weight of body due to bones not hardeningbody due to bones not hardening

* during childhood* during childhood

* from lack of Ca or vitamin D (sunlight)* from lack of Ca or vitamin D (sunlight)

In addition to being synthesized in the skin, vitamin D is also found in the following foods:

•Fatty fish •Fish liver oils •Fortified milk and dairy products •Egg •Butter

OsteoporosisOsteoporosis

Most common and severe bone diseaseMost common and severe bone disease

Loss of fiber and Ca in boneLoss of fiber and Ca in bone

Bone pain, curve of spine, break easilyBone pain, curve of spine, break easily

Bone strength Bone strength

1.1. Calcium amountCalcium amount * Ca in blood* Ca in blood * PTH released from parathyroid gland* PTH released from parathyroid gland * resorption by osteoclasts in bones* resorption by osteoclasts in bones * Ca released from the bone matrix and into the blood* Ca released from the bone matrix and into the blood2.2. ExerciseExercise * exercise* exercise * pressure on bone* pressure on bone * ossification (fibers)* ossification (fibers) * Ca being stored* Ca being stored * bone strength **the opposite is also true* bone strength **the opposite is also true

WARM UP 1/25 COPY THIS INFORMATION

2.2. ExerciseExercise * exercise* exercise * pressure on bone* pressure on bone * ossification (fibers)* ossification (fibers) * Ca being stored* Ca being stored * bone strength* bone strength

ALSO true of the oppositeALSO true of the opposite