Lecture 4a

Question 1

7 functions of bone

Answer 1

support
protect
anchor/movement
mineral storage
hematopoiesis (blood cell formation) 
triglyceride storage
hormone production

Question 2

Tissues types in the bone

Answer 2

bone
blood
cartilage
fat
ligaments/tendons

Question 3

Extracellular matrix

Answer 3

rigid and sturdy

-due to mineral deposit (calcium)

Question 4

Axial Skeleton

Answer 4

protect and support

Question 5

Appendicular Skeleton

Answer 5

movement

Question 6

Major types of bone and description

Answer 6

long bone-greater in length than width
short bone-nearly equal in length and width
flat bone-thin surfaces
irregular bone-complex shape

Question 7

Compact bone

Answer 7

• solid, smooth and relatively dense bone

- external surface of bone

Question 8

Spongy bone

Answer 8

• open lattice of narrow plates called trabeculae
• internal surface of the bone
• contains bone marrow

Question 9

Epiphysis

Answer 9

• knobby ends of long bones
• proximal and distal epiphysis
• covered in hyaline cartilage

Question 10

Diaphysis

Answer 10

-elongated cylindrical shaft with bone marrow cavity

Question 11

Medullary cavity

Answer 11

houses the yellow bone marrow

long axis of bone

Question 12

Metaphysis (epiphyseal plate)

Answer 12

• in between the diaphysis and the epiphysis

- contains the epiphyseal (growth) plate

Question 13

Periosteum

Answer 13

-outer layer of the bone
-covers external surface
-anchors blood vessels, nerves and tendons and ligaments
-dense irregular connective tissue
outer membrane-fibrous layer
inner membrane-osteogenic layer

Question 14

Osteogenic layers

Answer 14

osteoprogenitors
osteoblasts
osteoclasts

Question 15

Endosteum

Answer 15

• within the bone
• covers the internal surfaces of bone including the trabeculae
• same cells as inner layer of the periosteum (osteogenic layer)

Question 16

Osteoprogenitor cells

Answer 16

• stem cells
• found in the periosteum (inner layer) and endosteum
• differentiate in to osteoblasts

Question 17

Osteoblasts

Answer 17

• secrete bone matrix (osteoid) - collagen, calcium binding proteins
• when surrounded by the matrix it matures and becomes osteocytes
• responsible for bone growth

Question 18

Osteocytes

Answer 18

• final mature form of bone cells
• mature bone cells monitor and maintain the bone matrix
• resides in the lacunae
• detects mechanical stressors on bone
• communicates with osteoblast and osteoclasts during bone remodelling

Question 19

Osteoclasts

Answer 19

• bone dissolvers
• releases calcium
• ruffled membrane that increases the surface to volume ratio

Question 20

Osteon

Answer 20

• compact bone structure
• contains the lamellae and the central canal
• runs parallel to bone
• weight bearing pillars

Question 21

Lamellae

Answer 21

• matrix tubes, like the rings of a tree

- contains collagen fibres running adjacent to the lamellae to withstand torsional strain

Question 22

Central canal

Answer 22

contains blood vessels and nerves

Question 23

Perforating canal

Answer 23

connects the medullary cavity with the central canal

Question 24

Canaliculi

Answer 24

tiny canals connecting the lacunae with to eachother and the central canal

Question 25

Organic component of bone

Answer 25

resists stretch -bone cells -osteoid (collagen, bind specific proteins and ground substance) 1/3 of the bone

Question 26

Inorganic component of bone

Answer 26

resists to compression -mineral salts (calcium phosphate) 2/3 of the bone

Question 27

Comminuted fracture

Answer 27

- bone breaks into three or more pieces | - seen in old age, the bones are more brittle

Question 28

Compressed fracture

Answer 28

bone is crushed | -due to porous bone (osteoporotic bone) subjected to extreme trauma; fall

Question 29

Spiral fracture

Answer 29

- ragged break due to a twisting force applied to the bone | - most common in sports fractures

Question 30

Epiphyseal fracture

Answer 30

- the epiphyseal detaches from the diaphysis along the epiphyseal plate - tends to occur when the cells of the cartilage is dying and the calcification of the matrix is occurring

Question 31

Depressed fracture

Answer 31

the bone breaks inwards | -commonly seen in head injuries

Question 32

Greenstick fracture

Answer 32

- when the bone breaks incompletely, one side is broken and the other side is bending - this is seen in kids since they still have a more organic matrix that is more flexible than adults

Question 33

What are the projections

Answer 33

- trochanter - line - crest - tubercle - epicondyle - spine - process - tuberosity

Question 34

Surfaces

Answer 34

head facet condyle

Question 35

Depressions and openings

Answer 35

``` notch meatus groove fissure foramen sinus fossa ```