Growth

Identify 3 types of bone cells

1.

2.

3.

3 types of bone cells

Osteocytes (osteons) – mature bone cells, in both spongy and compact bone

Osteoclasts- multinucleated & dissolve bone matrix

Osteoblasts- build new cells

Osteons

Structures Functions Location Parallel to long axis of bone Therefore, limb does not bend Stress from one direction

Composition of bones

Compact

Spongy

Epiphyseal line/plate

What is the main difference between spongy and compact bone?

Why is a fracture more likely from the side of a bone?

What does the presence of an epiphyseal line mean?

Bones

If collagen increases in a bone, how is the strength of the bone affected?

What is the anatomical and thus physiological difference between the diaphysis and epiphysis ?

If osteoclast activity is higher than osteoblast activity what happens to a bone?

Calcification / ossification

Calcification vs. Ossification

Calcification

Buildup of Ca

Occurs during ossification

Can also occur in joints or other ares

Ossificiation

Intramembranous – bone develops directly

Endochondral – bone replaces catilage

Epiphyseal cartilage - at ends of epiphysis

reduces as growth slows

What affects the growth of bones?

Why do teens grow suddenly?What happens at puberty?

Is exercise important to bone development? How?

Primary/Secondary growth

Elongation –diaphysis growth Laterally- the periosteum is increasing in

osteoblasts, towards the inside, ________ are __________ and marrow cavity is increasing

When does one stop osteoblasting? Skull Toes Long bones Pelvis

What is needed for bone growth?

Vitamins and minerals Sex hormones Fractures – will they stop growth? Stress applied to bones- good or bad?

Why?

Vitamins

A

C

D

Minerals

Ca

P

Age Normal loss of bone due to aging= osteopeniaj Hormone levels change Reduction in osteoblast activity Bones become ----? Who is affected more? Men/women Is this equally affecting the entire body or are

some areas more affected earlier? What helps to reduce this process? Disorders/ diseases

What type of tissue is replaced by bone during intramembranous ossification?

How would an X-ray of a femur tell if a person had stopped growing?

Why should a pregnant woman take vitamin and mineral supplements?