Bone Tissue

Question 1

Bone Tissues Composition

Answer 1

Connective tissue (supports and maintains form)

Question 2

Organic Extracellular Component

Answer 2

33% is organic
- Collagen (long fibres throughout bone)
- Ground substance (proteoglycans - surround collagen)
- Functions to resist tension

Question 3

Inorganic Extracellular Component

Answer 3

67% is inorganic
- Mineral salts: makes bone hard and resistant to compression

Question 4

Cellular Component of Bone

Answer 4

2% of bone by weight
- Four types of cells
- Cells maintain bone homeostasis, bone destruction = bone formation

Question 5

Osteogenic Cells

Answer 5

Stem Cells, produce osteoblasts

Question 6

Osteoblasts

Answer 6

Produce new bone matrix

Question 7

Osteocytes

Answer 7

Control activity of osteoblasts/clasts, recycle protein and minerals from matrix

Question 8

Osteoclasts

Answer 8

Remove bone matrix

Question 9

Compact Bone : Macroscopically

Answer 9

Outer surfaces dense and impenetrable

Question 10

Compact Bone : Microscopically

Answer 10

Made up of circumferential lamelle and osteons

Question 11

Osteon

Answer 11

Longitudinal unit within compact bone
Provides pathway for nutrients and to get cells in ECM

Question 12

Central Canal

Answer 12

Contains blood vessels and nerves

Question 13

Lamellae

Answer 13

• Series of cylinders formed of ECM around central canal
• Form shape of osteon
• Collagen fibres within lamellae resist force

Question 14

Lacunae

Answer 14

Lakes for osteocytes

Question 15

Canaliculi

Answer 15

Channels for nutrients through ECM

Question 16

Trabeculae

Answer 16

Found in struts of lamella bone
Marrow fills the cavities between trabeculae
Osteocytes housed in lacuna in between lamella/on surface
Resists force from multiple directions spreads force distally

Question 17

Pelvic Girdle Force Distribution

Answer 17

Trabeculae channel weight around ilia into femora

Question 18

Bone Remodelling

Answer 18

Allows bones to grow appositionally
- Osteoblasts add bone matrix in lamelle
- Osteoclasts remove bone from medullary cavity

Question 19

Bone homeostasis

Answer 19

Balance of OB and OC
Bone is constantly being made and destroyed
Allows bones to mobilise calcium, phosphate and other minerals
If not maintained osteoporosis could form

Question 20

Epithelial Tissue

Answer 20

• Epithelia
• Glands (exocrine or endocrine)

Question 21

What are the three types of Connective Tissue?

Answer 21

• Proper: loose, dense
• Fluid connective tissues: blood, lymph
• Supporting connective tissues: cartilage, bone

Question 22

What are the three types of Muscle Tissue?

Answer 22

• Skeletal
• Cardiac
• Smooth

Question 23

Nervous Tissue

Answer 23

• Sensory input
• Control centre

Question 24

What is feedback in homeostasis ?

Answer 24

Returning the controlled variable to normal when it moves too far from the set point

Question 25

What is feedforward in homeostasis ?

Answer 25

• Minimising a future effect that would alter a controlled variable from set point