Growth of bone

1. Growth of Bone
Lloyd Dean
Skeletal System

2. Ossification
Humans have 206 bones
New born babies have more than
300!
In the embryo (our state before
birth) most of the skeleton is made
up of cartilage
Cartilage is a firm, but elastic
material

3. Ossification
As the embryo grows, cartilage is changed to bone
The development of bone from cartilage is termed “ossification”
Ossification is impacted by 3 cells
“Osteo” is Greek for “bone”
1.Osteoblasts
2.Osteocytes
3.Osteoclasts

4. Ossification
Completed during three stages:
3.Production of an extracellular matrix
Osteoblasts produce collagen (Tough elastic)
Calcium is utilised
4.Mineralisation of matrix to form bone
Osteoblasts fill spaces in bone with matrix, and then become trapped
There are then known as Osteocytes and have a star shape appearance
5.Bone remodelling
Osteoclasts break down bone and Osteoblasts rebuild them
Enables skeleton to repaid, adapt and build strong bones

5. Osteoblasts and Osteoclasts

6. Bone Remodelling

7. Osteoblasts, Osteoclasts and
Osteoporosis

8. Bone growth cannot occur without
sufficient dietary intake
Calcium required for bones
Vitamins C (Orange), A (Milk), K
(Wholegrain), and B
12
(Red meat) are
all necessary for bone growth
Nutritional Impact On Bone

9. Growth hormone stimulates bone growth
Thyroxine (Thyroid gland) increases the rate of osteoblast
activity
At puberty, sex hormones (estrogens in females and
androgens in males) cause osteoblasts to produce bone faster
than the epiphyseal cartilage can divide. Commonly know as
“growth spurt” as well as the closure of the epiphyseal
plate.
Estrogens cause faster closure of the epiphyseal growth plate
than androgens - Girls grow faster than boys!
Hormones Impacting Bone Growth