skeletal system

Question 1

Describe the difference between spongy and compact bone

Answer 1

• Spongy bone is made up of trabeculae. Trabeculae has holes and arches that contain bone marrow, allowing haematopoiesis to take place. It is found in the inner layer of flat and irregular bones, contributing to shock absorption. There are no osteons within spongy bone.
• Compact bone is the outer layer of long bones, it is dense and solid providing strength and protection. Compact bone has osteons.

Question 2

What are the main functions of the bone?

Answer 2

• Protection
• Support
• Movement
• Mineral storage
• Blood cell formation
• Hormone storage
• Hormone production
• Triglyceride (fat) storage in bone cavities

Question 3

What is haematopoiesis?

Answer 3

• Formation of blood cellular components

Question 4

What are the three sections/ layer of bone

Answer 4

• Proximal epiphysis
• Diaphysis
• Distal epiphysis

Question 5

What is the periosteum

Answer 5

• Thin layer of connective tissue that covers outer surface of bones, on all places except joints. It has a rich nerve supply.
• It has two layers: Fibrous & osteogenic

Question 6

What is an endosteum?

Answer 6

• Lining of cavities and canals that pass through compact bone. Release endosteal cells

Question 7

What are endosteal cells?

Answer 7

• They are bone lining cells that communicate with osteocytes.

Question 8

What are canaliculi?

Answer 8

• Is found in compact bone, they are hairlike canals that connect lacunae to each other and central canal.

Question 9

How is canaliculi formed?

Answer 9

• Osteoblasts secrete bone matrix
• They maintain close contact to each other and other bone cells.
• Mature osteocytes develop as bone matrix calcifies
• Then a very fine web of canaliculi is formed.

Question 10

What are synovial joints?

Answer 10

• Freely moveable joints
• It has synovial fluid, which is produced in the synovial membrane. It is made up of hyloronich acid and lubricate. It lubricates articular cartilage.

Question 11

What are the accessory structures of synovial joints, describe them.

Answer 11

• Bursae= fluid filled sacs allowing tendon and articulating cartilage to roll against each other without creating friction.
• Fat pads= contain fat cells, act as a cushion. Have a rich blood supply.
• Ligaments= Fibrous structure attaching bone to bone. They help to maintain the integrity of a structure.
• Menisci= made of fibrocartilage. They are two wedge shaped pieces of fibrocartilage that act as a shock absorber between the tibia and femur.
• Tendon= Attach muscle to bone. Tendon sheath wraps around the tendon and are fluid filled.