Skeletal System

Question 1

What are the main components of the skeletal system?

Answer 1

Bone and cartilage

Question 2

What is the role of hyaline cartilage in the skeletal system?

Answer 2

Provides firm support with some pliability

Covers the ends of long bones providing springy pads that absorb compression at joints

Question 3

What is the structure of hyaline cartilage?

Answer 3

Has cartilage cells (chondrocytes) located within lacunae in the tissue matrix

Vascularized perichondrium surrounds the cartilage, nourishing the tissue and producing new tissue.

Question 4

What is the role of fibrocartilage in the skeletal system?

Answer 4

Strong and compressible. Found in the knees and discs between vertebrae and pubis

Question 5

What is the structure of fibrocartilage?

Answer 5

Has rows of chondrocytes alternate with rows of thick collagen fibres.

Question 6

What are the main functions of the skeleton and of bone?

Answer 6

Support
Protection 
Movement 
Mineral Storage 
Blood cell formation
Fat storage
Hormone production

Question 7

What are the 4 shapes of bones?

Answer 7

Long bones
Short bones
Flat bones
Irregular bones

Question 8

Describe the structure of long bones.

Answer 8

Bones that are longer than they are wide. Has a shaft plus two ends

All limb bones are long bones. (named after elongated shape, not overall length)

Question 9

Describe the structure of short bones.

Answer 9

Cube shaped. The wrist and ankles are examples.

Sesamoid bones are a special type of short bone forms in a tendon.

Question 10

Describe the structure of flat bones.

Answer 10

Thin, flattened and usually a bit curved.

The sternum, ribs and most skull bones are flat bones

Question 11

Describe the structure of irregular bones.

Answer 11

Complicated shapes that fit none of the proceedings.

The vertebrae and hip bones are examples.

Question 12

What are the two types of bone?

Answer 12

Spongey bone

Compact bone

Question 13

Describe the gross anatomy of a compact bone.

Answer 13

Bone riddled with passageways that serve as channels for nerves, blood vessels and lymphatic vessels

Question 14

Describe the gross anatomy of a spongey bone.

Answer 14

Bone that aligns precisely along the lines of stress and help the bones resist stress.

Question 15

What are osteoblasts?

Answer 15

They are the ‘builder’ cells.

Matrix-synthesizing cells that are responsible for bone growth.

Osteoblasts produce calcium to the tissues, calcifying the tissue.

Question 16

What are osteoclasts?

Answer 16

They are bone-resorbing cells.

Polynuclear, meaning they produce a lot of proteinaceous enzymes and acidic compounds

The cells will push the ruffled border against bony material to digest it away.

Question 17

What do osteoblasts and osteoclasts work together to do?

Answer 17

They work together to continuously remodel the bone.

Question 18

What are osteocytes?

Answer 18

Mature bone cells that maintain the bone matrix.

Sit in the lacunae for years acting as sensory cells.

Question 19

What do bone lining cells do?

Answer 19

Work with and communicate with osteocytes to help regulate remodelling and repair of bony tissue.

Question 20

What is an osteon?

Answer 20

Group of hollow tubes of bone matrix.

Tiny weight-bearing pillars providing strength.

Question 21

What is the Haversian canal?

Answer 21

Runs through the core of each osteon. Contains small blood vessels and nerve fibres that serve the needs of the osteon’s cells.

Question 22

What are Volkmann’s canals?

Answer 22

Canals of a second type called Volkmann’s canals lie at right angles to the long axis of bone and connect the blood and nerve supply of the periosteum to the central canals.

Question 23

What are interstitial lamellae?

Answer 23

Incomplete lamelle. They fill the gaps between forming osteons

Question 24

What are circumferential lamellae?

Answer 24

Located just deep to the periosteum.

Resist the twisting of long bone.

Question 25

What is the chemical make-up of bone?

Answer 25

30% organic (for flexibility and strength) | 70% minerals (for hardness)

Question 26

What is osteoid?

Answer 26

Makes up ~1/3 of bone matrix. Contribute to bone structure and flexibility. Helps resist stretch and twisting.

Question 27

Explain why a bone is so tough and has great tensile strength.

Answer 27

A bone's resilience comes from the presence of sacrificial bones in or between collagen molecules. The bones break easily on impact, dissipating energy to prevent the force from rising to a fracture value. These bonds can re-form.

Question 28

What are synovial joints?

Answer 28

Joints in which the articulating bones are separated by a fluid-containing joint cavity. The arrangement permits substantial freedom of movement, and all synovial joints are freely moveable.

Question 29

Structure of synovial joint - Articular cartilage.

Answer 29

Glassy, smooth hyaline cartilage covers the opposing bone surfaces as articular cartilage. The thin but spongey cushions absorb compression placed on the joint.

Question 30

Structure of synovial joint - Joint cavity.

Answer 30

A feature unique to synovial joints, the joint cavity is really just a potential space that contains smalls mount of synovial fluid.

Question 31

Structure of synovial joint - Articular capsule.

Answer 31

The joint cavity is enclosed by a 2-layered articular capsule that is tough and fibrous. Strengthens the joint so the bones are not pulled apart.

Question 32

Structure of synovial joint - Synovial fluid.

Answer 32

Small amount of slippery fluid occupies all free spaces within the joint capsule. Delivered by filtration from blood flowing through capillaries in the synovial membrane.

Question 33

Structure of synovial joint - reinforcing ligaments.

Answer 33

Joints are reinforced and strengthened by ligaments.

Question 34

Structure of synovial joint - Nerves and blood vessels.

Answer 34

Joints are richly supplied with sensory nerve fibres that detect pain and monitor joint position and stretch.

Question 35

What are the 6 types of synovial joints?

Answer 35

1. Ball-and-socket joint 2. Hinge joint 3. Saddle joint. 4. Pivot joint 5. Condyloid joint 6. Gliding joint

Question 36

What is the bursae? (Synovial joint accessory structures)

Answer 36

The bursae are not strictly part of synovial joints, but often found closely associated with them. The bursae are bags of lubricant that reduce friction during joint activity.

Question 37

What are fat pads? (Synovial joint accessory structures)

Answer 37

Cushioning pads that absorb forces. A condition called Hoffa's disease is where this pad swells and gets pinched when the knee moves

Question 38

What are ligaments? (Synovial joint accessory structures)

Answer 38

Ligaments unit the bones and prevent excessive or undesirable motion. As a rule, the more ligaments a joint has, the stronger it is.

Question 39

What are the menisci? (Synovial joint accessory structures)

Answer 39

The medial and lateral meniscus are made of fibrocartilage and act as shock-absorbers of the stresses of walking, running, moving etc....

Question 40

What are the tendons and tendon sheaths? (Synovial joint accessory structures)

Answer 40

A tendon sheath is essentially an elongated bursa that wraps completely around a tendon subjected to friction. Common where several tendons are crowded together.