Bone from website

Question 1

function of bone

Answer 1

1. protect vital organs 2. store minerals such as calcium 3. store lipids (white bone marrow) 4. Make blood cells (haemopoesis)

Question 2

when the body needs calcium

Answer 2

the bone releases calcium

Question 3

calcium necessary for

Answer 3

muscle cotnraction, blood clotting, nerve conduction.., strength of bones andf teeth

Question 4

osteoclasts break down bone to

Answer 4

free calcium

Question 5

osteoblasts deposit

Answer 5

calcium in bone, remaking it

Question 6

bone cells are called

Answer 6

osteocytes

Question 7

osteocytes are found within

Answer 7

lucunae in each lacuna you will find one osteocyte

Question 8

canaliculi

Answer 8

connect lacuna allowing osteocytes to communicate with eachother via their processes (filapodia)

Question 9

two types of bone

Answer 9

compact cancellaneous (spongy)

Question 10

compact bone found

Answer 10

under the periosteum and in the diaphyses of long bones, where it provides support and protection.

Question 11

compact bone arranged into many

Answer 11

osteons- very regular pattern

Question 12

overview of osteon structure

Answer 12

The osteocytes sit in their lacunae in concentric rings around a central Haversian canal (which runs longitudinally).

The osteocytes are arranged in concentric rings of bone matrix called lamellae (little plates), and their processes run in interconnecting canaliculi.

The central Haversian canal, and horizontal canals (perforating/Volkmann’s) canals contain blood vessels and nerves from the periosteum.

Question 13

down the centre of an osteon is the

Answer 13

haversion canal

Question 14

what is found within the haversion canal

Answer 14

blood vessels, nerves and lymphatic vessels

Question 15

horizontal canals that flows between osteons

Answer 15

Volkmann canals - larger blood vessels and nerves - means there is a blood supply for all the bone tissue

Question 16

two kinds of bone including compact, whoch is the other

Answer 16

Cancellous bone

Question 17

cancellous bone

Answer 17

also known as spongy or trabecular bone, is one of the two types of bone tissue found in the human body. Cancellous bone is found at the ends of long bones, as well as in the pelvic bones, ribs, skull, and the vertebrae in the spinal column

Question 18

difference between Cancellous (spongy bone) and compact bone

Answer 18

much less dense and less regular

Question 19

what is the outer most layer of bone (continous with ligaments and tendons)

Answer 19

periosteum

Question 20

down the centre of the long bone is the

Answer 20

medullary cavity

Question 21

medullary cavity contains

Answer 21

yellow bone marrow

contains largest blood vessels/ nerves

Question 22

blood vessels and nerves in the medullary cavity

Answer 22

enter the bone tissue and allow for noruishment of individual osteocytes

Question 23

endosteum

Answer 23

The endosteum (plural endostea) is a thin vascular membrane of connective tissue that lines the inner surface of the bony tissue that forms the medullary cavity of long bones.

Question 24

outline the gross structure of a long bone

Answer 24

epiphysis

metaphysis

diaphysis

Question 25

where is red bone marrow found

Answer 25

at the proximal and distal end sof the bone within spongy cancellous bone

Question 26

outer layer of bone composed of

Answer 26

compact bone

Question 27

compact bone

Answer 27

dense material with low porosity

Question 28

spongy cancellous (trabecular) tissue

Question 29

red bone marrow

Answer 29

makes blood cells- haemopoesis

Question 30

yellow bone marrow

Question 31

shape of osteocyte

Answer 31

star shaoed- long projections (filipodia/ processes) that prokect into canaliculi

Question 32

structure of spongy bone looks like

Answer 32

honeycombe

Question 33

each rod of bone in spongy bone that looks like honeycomb is called

Answer 33

a trabecula or spicule

Question 34

trabeculae (in spongy bone) dont contain

Answer 34

osteons

haversian

Question 35

matrix of spongy bone

Answer 35

o contain lamellae, or layers of bone matrix, but the lamellae are parallel to each other. The matrix contains lacunae and canaliculi, as well as osteocytes, osteoblasts, and osteoclasts.

Question 36

when the amount of bone manufacture equals the amoutn of disintegrations

Answer 36

the mass of a bone stays the same

Question 38

how do osteoblasts form new bone

Answer 38

osteoblasts move over the matrix of a bone and deposit a protein mixture called osteoid. The osteoid contains a protein called collagen as its major component. Then the osteoblasts deposit minerals—including calcium—into the osteoid to make bone. The new material fills in the cavity formed by osteoclasts.

Question 39

osteocytes

Answer 39

Some osteoblasts become trapped in the bone matrix and are transformed into osteocytes inside lacunae. Osteocytes are thought to be sensory cells that are involved in signaling processes inside the bone. They connect to other osteocytes through their projections, which extend through the canaliculi. They are the most abundant cells in bone and also appear to have the longest lifespan.

Question 40

osteoclasts

Answer 40

Unlike osteoblasts, osteoclasts contain more than one nucleus. They are large cells produced by the fusion of several smaller ones. Osteoclasts travel over the surface of the bone matrix and secrete acids and enzymes to disintegrate it, forming a little pit on the surface of the bone.

• absrob mineral- which is later relased intot he tissue fluid located between cells
• fromt here the ions enter the blood

Question 41

which hormone stimulate sthe action of osteoclasts

Answer 41

parathyroid hormone

Question 42

parathyroid hormone

Answer 42

stimulates the action of osteoclasts when the amount of calcium in the blood falls. The hormone causes the transfer of calcium from bone to blood.

Question 43

which thryoid hormone is produced which slows the activity of osteoclasts- decreasing the bone breakdown

Answer 43

calcitonin

Question 44

what can help increase bone production

Answer 44

when someone performs regular weight-bearing exercise

Question 45

when someone is bedridden the net effect is

Answer 45

bone loss

Question 46

which hormones in men and women help maintain bone strength

Answer 46

testosterone- men

oestrogen- women

Question 47

osteoporosis summary

Answer 47

Osteoporosis is a disorder in which the bones become unusually porous and brittle and bone density decreases. The condition generally appears in older people, although it occurs in young ones as well. In osteoporosis the amount of bone resorption is much higher than the amount of bone production.

Osteoporosis can occur in both males and females, but it’s most common in post-menopausal women. After menopause the amount of estrogen in a women’s body decreases significantly, increasing the risk of weakened bones.

Question 48

general cause of osteoporosis

Answer 48

amount of bone resorption is much higher than the amount of bone production