Bones and Joints

Question 0

State some metabolise processes of the skeleton and where abouts in the bone they occur.

Answer 0

Haemopoiesis in red marrow.
Lipid storage in yellow marrow.
Mineral storage in bone matrix, e.g. Calcium and phosphate.

Question 1

State some mechanical roles of the skeleton.

Answer 1

Support, protects, provides shape and movement, attachments for muscles and levers.

Question 2

Name the 5 bone type/shapes and give examples of each.

Answer 2

Long bones e.g. Humerus.
Short bones e.g. Calcaneus.
Flat bones e.g. Skull
Irregular bones e.g. Scapula. Either accessory (2nd ossification centres) or pneumatic which have air in them, e.g. Sinus.
Sesamoid e.g. Patella

Question 3

Define a joint.

Answer 3

Articulation between 2 or more bones.

Question 4

What are the 3 classifications of joint types?

Answer 4

Fibrous, cartilaginous and synovial.

Question 5

What 3 factors does the stability of joints depend on?

Answer 5

The shape, size and arrangement of the articulating surfaces.
The ligaments.
The tone of the muscles around the joint.

Question 6

What are the 2 types of cartilaginous joints, what’s the difference between them and where can they be found?

Answer 6

In cartilaginous joints there is a piece of cartilage holding the bones together. The bones in primary/synchondroses are held together by hyaline cartilage, e.g ilium. They are often temporary and replaced by bone. The bones in secondary/symphyes are covered by fibrocartilage, e.g. Pubis symphysis. Tend to be permanent joints.

Question 7

In synovial joints, where is the synovial fluid secreted from?

Answer 7

From the serous synovial membrane which is the internal lining of the fibrous capsule.

Question 8

What movement does a hinge joint allow?

Give an example of where it’s found.

Answer 8

Flexion and extension.

Elbow.

Question 9

What movements does a condyloid joint permit?

Give an example of its location.

Answer 9

Flexion and extension, abduction and adduction and circumduction.
MCP joint.

Question 10

Does cartilage contain blood vessels?

Answer 10

No, it’s avascular.

Question 11

How does the blood supply enter bone?

Answer 11

Via Haversian system and Volkmans canals.

Question 12

What embryonic cell are all bones derived from?

Answer 12

Mesenchymal tissue.

Question 13

What are the two ways of ossification and what’s the difference between them?

Answer 13

Intramembranous ossification- mesenchymal condenses.
Endochondral ossification- replacement of pre-existing hyaline cartilage by bone. Develop primary and then secondary ossification centres.

Question 14

What is osteogenesis imperfecta?

Answer 14

Autosomal dominant disorder of connective tissue, due to a mutation in type 1 collagen. Causes fractures.

Question 15

What is osteoporosis and what is the difference between the two types?

Answer 15

Reduction in quantity of bone/atrophy of skeleton due to enhanced bone reabsorption compared to formation. Type 1 occurs in post menapausal women where there is an increase in osteoclasts number due to a withdrawal of oestrogen. Type 2 occurs in the elderly due to attenuated osteoblasts function.

Question 16

What is osteomalacia what are some of the associated symptoms?

Answer 16

Adult version of rickets, due to a lack of calcium or vitamin D. Symptoms include bone pain, back ache and muscle weakness. Bones are soft so can fracture.

Question 17

What is rickets?

Answer 17

Childhood disease where bones don’t harden due to a vitaminD deficiency. Bones are soft and weak, which can lead to deformities such as bowed legs. Can get bone pain and poor growth.

Question 18

What is Paget’s disease?

Answer 18

A disruption to the normal cycle of bone renewal and repair. Bones become weak and deformed and you get bone pain. Bone is replaced at a faster rate then usual, so get enlarged bones that are weak and brittle. Influenced by genetic and environmental factors.