Bone Development And The Mesoderm

Question 1

When does osteogenesis occur?

Answer 1

• 6-7 weeks of embryonic development,and continues into adulthood (approx age 25 years)

Question 2

What are two types of bone ossification ?

Answer 2

• intramembranous
• endochondrial

Question 3

Outline the 1st step of intramembranous ossification;

Answer 3

• mesenchymal cells differentiate into osteoblasts and group into ossification centres

Question 4

Outline the 2nd step of intramembranous ossification;

Answer 4

Osteoblasts become entrapped by the osteoid ,they secrete, transforming them to osteocytes

Question 5

Outline the 3rd step of intramembranous ossification;

Answer 5

Trabecular bone and periosteum form

Question 6

Outline the 4th step of intramembranous ossification;

Answer 6

Cortical bone forms superficially to the trabecular bone

Question 7

Outline the 5th step of intramembranous ossification;

Answer 7

Blood vessels form the red marrow

Question 8

What is endochondrial ossification?

Answer 8

A type of bone formation that requires a cartilage template for development

Question 9

Where does endochondrial ossification originate from?

Answer 9

Embryotic mesoderm

Question 10

Outline the definition of the perichondrium?

Answer 10

When chondocytes form the membrane surrounding the cartilage

Question 11

What are two types of attachments to muscle?

Answer 11

• tendons
• ligaments

Question 12

Outline the definition and an example of tendons,

Answer 12

W flexible but in elastic cord of steering fibrous collagen that connects a muscle to a bone
Example- Achilles tendon

Question 13

Outline the definition and an example of ligaments;

Answer 13

A tough band of tissue that holds bones/organs in position

Example- cruciate ligament

Question 14

Outline functions of the hyaline cartilage found in the joints

Answer 14

• colourless/transparent

-often found in joints where it protects from bone-on-bone friction

-chondrocytes are the cell type produce collagen and ground substance

-when damaged it is difficult for body to repair due to avascular

Question 15

Where and what is a pivot joint?

Answer 15

Found in the neck

Joint between the atlas and axis, directly under the skull, allowing turning of the head from side to side

Question 16

What is osteogenesis?

Answer 16

-brittle bone disease

-affects the connective tissue,caused by abnormal or reduced collagen production

Question 17

Outline type 1 of osteogenesis imperfecta;

Answer 17

-no symptoms at birth, may have hearing loss due to abnormalities in tiny bones in the inner ear

Question 18

Outline type 2 of osteogenesis imperfecta;

Answer 18

Present at birth, often result in still born/ fractures at birth, serve disability- very short life span, patient usually doesn’t survive u til adulthood

Question 19

Describe type 3+4 of osteogenesis imperfecta;

Answer 19

Similar to type 1 - with varying severity

Question 20

Outline what osteroporosis is?

Answer 20

-loss of bone mass

-often in past menopausal women, causes weakened bones that are more susceptible to injury

Question 21

What is rickets?

Answer 21

Softening of bones, caused my vitamin D deficiency

Question 22

How are rickets treated?

Answer 22

By eating calcium enriched/ vitamin supplements

Question 23

Describe paget disease;

Answer 23

Leading to weak deformed bones

The microscopic structure of the bone is not normal