Laboratory 12: Bone structure and classification

Question 1

What does the bone represent?

Answer 1

An organ of the skeletal system.

Question 2

What is bone composed of?

Answer 2

Osseous tissue, cartilage, dense connective tissue, blood and nervous tissue.

Question 3

What are the functions of bone?

Answer 3

Support and protect softer tissues, provide points of attachment for muscles, house blood-producing cells, help buffer the blood from extreme fluctuation in pH and to store organic salts.

Question 4

What does the extracellular matrix surrounding bone contain?

Answer 4

One third organic matter, two thirds inorganic.

Question 5

What does the organic matter consist of?

Answer 5

Consists of mostly collagen fibers that provide flexibility and strength to withstand tension.

Question 6

What is the inorganic matter?

Answer 6

Mostly hydroxapatite, complex salt crystals consisting of calcium phosphate.

Question 7

What are osteogenic stem cells?

Answer 7

They differentiate into osteoblasts that help form bone.

Question 8

What do osteoblasts isolated in matrix do?

Answer 8

Osteoblasts form osteocytes when isolated in matrix that are vital to bone homeostasis.

Question 9

What do osteoclasts do?

Answer 9

Dissolve bone to release calcium salts.

Question 10

How are bones classified in regards to shape?

Answer 10

As long, flat, short, and irregular.

Question 11

How would you describe long bones?

Answer 11

Long bones are longer then they are wide and have expanded ends.

Question 12

How would you describe short bones?

Answer 12

Short bones are somewhat cube shaped with similar lengths and widths.

Question 13

How would you describe sesamoid bones?

Answer 13

A special type of short bones. They are small and embedded within a tendon near joints where compression often occurs.

Question 14

What type of bone is the patella?

Answer 14

Located in the knee, it is a sesamoid bone.

Question 15

How would you describe flat bones?

Answer 15

Flat bones have wide surfaces but they can be curved such as those of the cranium

Question 16

How would you describe irregular bones?

Answer 16

Have numerous shapes and often have articulations with more then one other bone.

Question 17

What is the supportive tissue during embryonic and fetal development?

Answer 17

Cartilage.

Question 18

Where is cartilage retained in the adult skeleton?

Answer 18

Articulating surfaces of moveable joints, coastal cartilage connecting the ribs to the sternum and intravertebral discs between the vertebrae.

Question 19

What does the compact bone contain?

Answer 19

Contains cylinder shaped units called osteons.

Question 20

What does an osteon contain?

Answer 20

Contains a central canal that includes blood vessels and nerves in living bones and is encircled by concentric lamellae.

Question 21

Where are the cells or osteocytes?

Answer 21

Located in concentric circles within almond shaped cavities known as lacunae.

Question 22

What do the cellular processes of osteocytes go through?

Answer 22

Microscopic canaliculi

Question 23

What do microscopic canaliculi do in regards to compact bone?

Answer 23

Allow for the transport of nutrient and waste substances between the cells and the central canal.

Question 24

What does the spongy bone contain?

Answer 24

The osteocytes of spongy bone are located within a lattice of boney plates known as trabeculae.

Question 25

What do the canaliculi do in regards to spongy bone?

Answer 25

Canaliculi allow for diffusion of substances between the cells and the marrow that is positioned between the trabeculae.

Question 26

What are some examples of long bones?

Answer 26

Femur. humerus, phalanges.

Question 27

What are some examples of short bones?

Answer 27

Carpals, tarsals, sesamoid bones.

Question 28

What are some examples of flat bones?

Answer 28

Ribs, scapula, sternum most cranial bones.

Question 29

What are some examples of irregular bones?

Answer 29

Vertebra, sphenoid

Question 30

What is an osteon?

Answer 30

Cynlinder shaped unit within compact bone.

Question 31

What is the central canal?

Answer 31

Located within the osteon, contains blood vessels and nerves.

Question 32

What is the concentric lamella?

Answer 32

Concentric ring of matrix around central canal of osteon.

Question 33

What is the interstatial lamella?

Answer 33

Matrix between osteons composed of the remains of old osteons.

Question 34

What is the circumferential lamella?

Answer 34

Matrix that runs parallel to the surface of the bone.

Question 35

What is the lacuna?

Answer 35

Small chamber for an osteocyte.

Question 36

What is the bone extra cellular matrix?

Answer 36

Collagen and calcium phosphate.

Question 37

What is the canalicus?

Answer 37

Minute tube containing cellular process.

Question 38

What is the perforating canal?

Answer 38

Runs perpendicular to central canal contains blood vessels and nerves.

Question 39

What is the epiphysis?

Answer 39

Enlarged ends of a long bone.

Question 40

What is the epiphyseal plate?

Answer 40

Growth zone of hyaline cartilage.

Question 41

What is the epiphyseal line?

Answer 41

Site of original epiphyseal plate that has completely ossified.

Question 42

Where is the articular cartilage

Answer 42

On end of epiphyses.

Question 43

Where is diaphysis?

Answer 43

Shaft between epiphyses.

Question 44

Where is the periosteum?

Answer 44

Strong membrane around bone of dense irregular connective tissue. Not at the surface of joints

Question 45

Where is spongy bone?

Answer 45

Within epiphyses

Question 46

What is the medullary cavity?

Answer 46

Hollow chamber in diaphysis contains bone marrow.

Question 47

What is the endosteum?

Answer 47

Thin membrane of reticular connective tissue that lines the medullary cavity.

Question 48

What is yellow bone marrow?

Answer 48

Occupies medullary cavity and stores adipose tissue.

Question 49

What is red bone marrow?

Answer 49

Occupies spongy bone in some epiphyses and flat bones and produces blood cells.