Fetal Skeletal Development and Ossification

At what stage of fetal development does the skeleton originally start growing?

• About 6 weeks into fetal development

• At birth

• After 3 months

• During childhood

What are all skeletal elements originally made of?

• Cartilage

• Bone

• Muscle

• Tendons

Tags

NGSS.MS-LS1-3

NGSS.MS-LS1-1

Which statement best describes cartilage?

• A connective tissue with a gel-like matrix containing a lot of fibers

• A hard tissue with no fibers

• A liquid tissue with no structure

• A fatty tissue with few fibers

Tags

NGSS.MS-LS1-3

NGSS.MS-LS1-2

Where does intramembranous ossification occur?

• Within sheets or membranes of connective tissue

• Inside muscle fibers

• In the blood vessels

• In the digestive tract

Which bones develop by intramembranous ossification?

• Flat bones of the skull, mandible, clavicles

• Long bones of the legs

• Ribs and vertebrae

• Pelvic bones

What is the starting point for bone formation in intramembranous ossification?

• Ossification center

• Growth plate

• Bone marrow

• Cartilage model

Most bones form through which type of ossification?

• Endochondral ossification

• Intramembranous ossification

• Interstitial ossification

• Appositional ossification

What is the first step in endochondral ossification?

• Ossification starts at the chondrocytes within the cartilage

• Blood vessels grow into the cartilage

• Osteoblasts break down bone

• Secondary centers of ossification form

What happens when chondrocytes enlarge during endochondral ossification?

• The surrounding matrix calcifies

• The bone shrinks

• The cartilage dissolves

• The tissue becomes fatty

What do newly developed osteoblasts do during endochondral ossification?

• Cover the diaphysis of the cartilage model in a thin layer of bone

• Remove calcium from the bone

• Destroy the cartilage

• Form muscle tissue