How the epiphyseal plate forms into the epiphyseal line

step 1

There are four layers that make up the epiphyseal plate. The top zone is called the resting cartilage, and is fixed to the epiphysis

step 2

The second zone below the resting cartilage is called the zone of perliferating cartilage, where the cartilage pushes the resting cartilage as it expands and divides, causing the diaphysis to lengthen

step 3

In the zone below the proliferating cartilage, the hypertrophic zone. In this zone, chondrocytes mature and expand. this process expands lecunae and contributes to the diaphysis’ growth

step 4

The lowest zone, the calcified cartilage is made up of old and dying chondrocytes. The cartilage matrix calcifies. Osteoclasts break down the cartilage, allowing osteoblasts to deposit new boney matrix. This increases the cell number and adds to the growth.

step 5

this process continues until the epiphyseal plate is closed, forming the epiphyseal line

How does estrogen play a role in

estrogen plays the role of finalizing the length of the plates

how does testosterone play a role in bone elongation

Testosterone stimulates osteoblasts, leading to the increase of density

what glands do Testosterone, estrogen, and human growth horomes come from

Estrogen: ovaries

testosterone: testicles, adrenal glands

HGH: pituitary gland