The Skeletal System

Question 1

Haversian (central) canal

Answer 1

Contains blood vessels and nerves

Question 2

Concentric lamellae

Answer 2

circular plates of bone that surround Haversian canal

Question 3

Lacunae

Answer 3

fluid filled small openings in concentric lamellae

Question 4

Osteocytes

Answer 4

Mature bone cells that cannot divide.

• Maintain normal bone structure
• Found in Lacunae

Question 5

Canaliculi

Answer 5

Small canals that transmit nutrient-containing fluid from blood stream to the osteocytes.
- Connects lacunae

Question 6

Volkman’s (perforating) canals

Answer 6

Canals that run perpendicular to and connect Haversian canals

Question 7

Compact bone

Answer 7

Hard layer of bone that covers the outer surface of most bones and forms almost the entire shaft length of long bones

Question 8

Cancellous (spongy) bone

Answer 8

Composed of branching needles or struts of bone, called trabeculae, arranged to form a porous network.
- Pours or spaces are filled with marrow

Question 9

Osteoblasts

Answer 9

Bone forming cells found on the inner and outer surface of bone.
- Can undergo mitosis to form new bone cells

Question 10

Osteogenesis

Answer 10

Process that produces new bone

Question 11

Osteoclasts

Answer 11

Multinucleated bone destroying cells that dissolve the bony matrix through osteolysis or bone resorption

Question 12

Long bones

Answer 12

Much longer in one dimension than the other two dimensions

• Ex: humerus, femur
• Fxns as levers in locomotion and support

Question 13

Short bones

Answer 13

Equal in size in all 3 dimensions

• Ex: carpal, tarsals

Question 14

Flat bones

Answer 14

Relatively thin bones that are expanded in two dimensions

• Ex: scapula/shoulder blade, bones of the skull, ribs
• Fxn: protection and for muscle attachment

Question 15

Sesamoid bone

Answer 15

Bones whose shape resembles a sesame seed

• Ex: patella, kneecap, proximal and distal sesamoid bones in the digits or quadrupeds
• Fxn: reduces friction or change course of a tendon

Question 16

Irregular bones

Answer 16

Shape does not fit another category. Most located on median plane of body and not paired

• Ex: vertebrae, sternum

Question 17

Medullary (marrow) cavity

Answer 17

Space in shaft of long bone that contains bone marrow

• Fxn: blood cell formation occurs

Question 18

Epiphysis

Answer 18

Enlarged regions on both ends of long bone

• Distal and proximal epiphysis

Question 19

Diaphysis

Answer 19

Cylindrical shaft of the bone

Question 20

Metaphysis

Answer 20

The flared area of mature bone found between epiphysis and diaphysis

Question 21

Periosteum

Answer 21

Membrane that covers the entire outer surface of bone except where articular cartilage is located

Question 22

Endosteum

Answer 22

Membrane that lines the inner surface of bone