Bone growth and related hormones for chapter 6 quiz

Longitudinal growth

growth in length of long bones

Stage 1 Longitudinal growth

New cartillage forms while chondroblasts divide to create cartilage matrix

Stage 2 Longitudinal growth

Cartilage is replaced with bone and everything else invades the area

Appositional growth

Process that enlarges the thickness and diameter of bone

Stage 1 of appositional growth

Osteoblasts within periosteum secretes new bone matrix on external bone surface

What do the osteoblasts in Stage 1 of appositional growth form

Circumferential lamellae

Stage 2 of appositional growth

Osteoclasts remove old bone from endosteal surface and enlarge the marrow cavity

What secretes the growth hormone?

The pituitary gland

What does the growth hormone do?

• stimulates division of chondroblasts in epiphyseal plate

• stimulates division and activity of osteoblasts

• Increases calcium retention

• Increases bone mineralization

Childhood hyposecretion

Dwarfism

Childhood hyper secretion

gigantism

Adult hypersecretion or GH abuse

Acromegaly

What glands secrete the parathyriod hormone

parathyriod hormones

Parathyriod hormone function:

Increases blood calcium levels and is the receptor when low blood calcium

Why is vitamin D important

It increases calcuim absorbtion

What is calcitonin secreted by

Thyriod gland

Purpose of calcitonin

Reduced blood calcium

Sex hormones that promote bone density

Estrogen, testosterone, and adrenal cortex

Sex hormone that promote bone mass

Testosterone and adrenal cortex

Sex hormones that inhibit osteoclasts and stimulates osteoblast activity

Estrogen and adrenal cortex