Bone II- bone tissue and structure

Question 1

What is the function of a central canal?

Answer 1

To contain the blood vessels and nerves

Question 2

What is the purpose of the organisation of trabeculae in cancellous bone?

Answer 2

• resists force in multiple directions

- directs body weight force down diaphysis

Question 3

What are the two main functions of the lamellae?

Answer 3

• form the shape of the osteon

- collagen fibres within lamellae resist forces

Question 4

What is an osteogenic cell?

Answer 4

Stem cell that produces osteoblasts

Question 5

what are Lacunae?

Answer 5

Lakes for osteocytes

Question 6

What is the Medullary cavity?

Answer 6

The hollow part of bone containing bone marrow

Question 7

What cell removes and destroys bone matrix?

Answer 7

Osteoclast

Question 8

What is osteoporosis caused by? What are the results?

Answer 8

OC> OB activity, trabecular in cancellous bone becomes thinner, making bones brittle and likely to fracture

Question 9

What is the function of an osteon?

Answer 9

provides a pathway for nutrients to get to cells in the ECM

Question 10

What are longitudinal units within compact bone called?

Answer 10

osteons

Question 11

What does an osteon contain?

Answer 11

• central canal
• Lamellae
• Lacunae
• Caniculi

Question 12

Where are osteocytes on cancellous bone

Answer 12

in lacuna between lamellae or on surface of trabeculae

Question 13

What are Canaliculi?

Answer 13

Channels for nutrients through ECM

Question 14

What is the function of an osteocyte?

Answer 14

Communication and maintenance- recycles proteins in matrix

Question 15

What are the inorganic components of bone ECM?

Answer 15

hydroxyapatite + other Ca minerals

Question 16

What is The hollow part of bone containing bone marrow called?

Answer 16

The medullary cavity

Question 17

Name the 4 types of cells in the bone?

Answer 17

• osteoblasts
• osteocytes
• osteoclasts
• osteogenic cells

Question 18

What is appositional growth?

Answer 18

Growth by forming new layers on the surface of pre-existing layers; process of increasing in thickness rather than length.

Question 19

What are Osteons?

Answer 19

Osteons are longitudinal units within compact bone

Question 20

What is the function of an osteoclast

Answer 20

removes and destroys bone matrix

Question 21

How much of bone ECM is organic?

Answer 21

33%

Question 22

What is Lammellae?

Answer 22

A series of cylinders of ECM around the central canal

Question 23

What structure does compact bone have that isn’t present in trabeculae/ cancellous bone?

Answer 23

Central Canal

Question 24

What is Bone Homeostasis

Answer 24

Maintaining a balance of OC and OB activity

Question 25

what is the name of a cell that produces bone matrix?

Answer 25

Osteoblast

Question 26

What is the name of a Stem cell that produces osteoblasts?

Answer 26

osteogenic cell

Question 27

What are the organic components of bone ECM

Answer 27

- collagen (protein) | - Ground substance ( proteoglycans)

Question 28

What are the benefits of bone homeostasis?

Answer 28

- Allows body to mobilise calcium, phosphate, and other bone. matrix nutrients - Shape change possible throughout life to resist strain - allows bone to respond plastically to stress

Question 29

What do humans have to do to ensure bone homeostasis

Answer 29

- consume adequate calcium | - moderate excersise

Question 30

How does appositional growth occur in long bones?

Answer 30

- osteoblasts secrete bone matrix to create new layers/ lamellae - osteoclasts remove bone from medullary cavity to prevent heaviness

Question 31

What are Trabeculae

Answer 31

Bands or columns of connective tissue forming cancellous bone

Question 32

What percentage of bone ECM is inorganic?

Answer 32

67%

Question 33

What is the function of an osteoblast?

Answer 33

produces bone matrix

Question 34

What fills the cavities between trabeculae?

Answer 34

Bone Marrow

Question 35

What cell is responsible for Communication and maintenance- recycling proteins in matrix?

Answer 35

Osteocyte