Lecture 7

Question 1

the primary functions of bone

Answer 1

support
anchor
protection
movement
mineral and fat storage
hematopoiesis
hormone reproduction
respiration
hearing

Question 2

primary function of support in bones

Answer 2

the bones support the body and protect the inside components of the body

Question 3

primary function of an anchor in bones

Answer 3

the bones anchor the muscles to bones to allow leverage and movement in the body

Question 4

primary function of protection in bones

Answer 4

the bones just like they support the body provide a layer of protection for things like the organs

Question 5

primary function of movement in bones

Answer 5

the bones help to work with the other systems to allow the body to move

Question 6

primary function of fat and mineral storage in bones

Answer 6

bones serve as a reservoir for minerals in the body especially calcium and phosphorous

Question 7

hematopoiesis and bones

Answer 7

hematopoiesis is the formation of blood cells (within the yellow marrow) which happens in bones

Question 8

hormone production in bones

Answer 8

hormones can be produced in the bones through the production of osteoclacin

Question 9

respirations role with bones

Answer 9

allows doe the rib cage to expand or contract so that we can breathe. The bones in the nasal cavity also allow for air to warm up before we breathe it in

Question 10

hearing with bones

Answer 10

without the bones in our ears we would not be able to hear anything

Question 11

weight in bones

Answer 11

• If you gain weight the bones will become stronger, but if you no longer need the extra support, since you get new ones every ten years, you will no longer use or have it.

Question 12

major difference between spongy and compact bones

Answer 12

the only major difference is the way in which the cells are organized

Question 13

spongy bone

Answer 13

• More porous and lightweight than compact bone
• Has trabeculae which is a honeycomb of small needle-like of flat pieces
• Strong enough to withstand most of the forces we put on it, but not too heavy for us to carry it around

Question 14

compact bone

Answer 14

Compact bone is made up of functional units called osteons, which are long cylindrical unites. Each osteon has a central canal surrounded by lamellae.
- the compact bone has collagen fibers in spaces called lacunae, and compact bone makes up 80% of the total weight of bones in the body

Question 15

the structural components of the long bone

Answer 15

medullary cavity
diaphysis
epiphysis
metaphysis

Question 16

diaphysis

Answer 16

the shaft of the long bone

Question 17

epiphysis/epiphyses

Answer 17

the ends of long bones

Question 18

metaphysis

Answer 18

where the bone starts to flare out and get wider

Question 19

medullary cavity

Answer 19

the middle of the bone, contains no bone tissue. “the marrow cavity” in youth it is red marrow (which produces your blood cells), in adults this is replaced by yellow marrow (fat) at maturity

Question 20

what happens to marrow if the body is anemic

Answer 20

if the body is anemic your body can revert back and produce red marrow even after reaching maturity

Question 21

periosteum

Answer 21

• a double-layered membrane covering external surface of the bones (except in the joints)
• Clings tightly to the surface of bones, is richly vascularized and innervated
• A glistening, white double-layered membrane

Question 22

endosteum

Answer 22

• a membrane lining the internal structure of the bone
• Has stem cells that can eventually turn into bone cells
• A delicate connective tissue membrane that covers internal bone structures

Question 23

composition of organic and inorganic of the bone

Answer 23

35% organic
65% inorganic

Question 24

organic versus inorganic

Answer 24

• 35% organic – bone cells and osteoid (collagen (and proteins), proteoglycans, and glycoproteins)
  
  • If you remove the organic component, then the bone becomes brittle
• 65% inorganic – hydroxyapatites: calcium-containing crystalline structures
  
  • If you remove the inorganic component, it doesn’t necessarily become more brittle but loses its rigidity and only is flexible.

Question 25

osteogenic cells

Answer 25

• Also called osteoprogenitor cells – bone stem cells, can differentiate and develop into osteoblasts. (found in the periosteum and endosteum)

Question 26

osteoblast

Answer 26

• Bone-building cells. Secrete osteoid and create new bone tissue during growth and remodeling

Question 27

osteocyte

Answer 27

• Mature bone cells, for when osteoblasts become trapped within their own secreted matrix from so much osteoid that they can’t secrete anymore and become osteocytes. Can sense the mechanical stress on the bone and communicate with other bone cells

Question 28

osteoclast

Answer 28

• Large cells that resorb (break down) bone. Secrete enzymes that break down bone. In their own area secrete special enzymes to break these down (parathyroid hormone)

Question 29

skeletal system in maintaining calcium homeostasis

Answer 29

• Calcitonin: this can weakly inhibit osteoclast activity. When there is too much calcium it triggers the thyroid gland to increase the release of calcitonin to stop the osteoclasts from working
• Parathyroid hormone (PTH): it stimulates osteoclast activity.

Question 30

explain the roles of the parathyroid hormone and calcitonin on blood calcium regulation

Answer 30

• Calcitonin works to weakly inhibit the osteoclasts’ activity and prevent them from working to produce osteoid.
• While the parathyroid hormone works to stimulate the osteoclast activity to increase the release and break down bone tissues.

Question 31

osteon

Answer 31

(Haversian system): functional unit of compact bone. Is the tree trunk section that looks concentric (is the whole cell)

Question 32

central canal

Answer 32

(Haversian canal): contains blood vessels and nerve fibers. This is the opening that runs through the center of the bone that things need to travel through

Question 33

lacunae

Answer 33

the space that osteocytes occupy

Question 34

canaliculi

Answer 34

the tiny canals that connect osteocytes together. They send signals and allow the osteocytes and the canaliculi to communicate and transport nutrients with each other

Question 35

lamellae

Answer 35

the concentric rings/layers within the osteon. (the layers that we see in each osteon)

Question 36

perforating (Volkmann’s canals)

Answer 36

these run perpendicular to the central canals. They run in the opposite direction, have nerves and fibers but work to transport things across from one osteon to another (looks like a vessel)

Question 37

• Describe how the microscopic structure of spongy bone relates to mechanical stress placed on the bone

Answer 37

• The structure of spongy bone can get stronger by the more stress than is replaced on the bone/skeleton. The areas with the most stress have the most trabeculae. They are aligned to be stronger because of the stress put on them

Question 38

endochondral ossification

Answer 38

• Endochondral – when hyaline cartilage is converted into bone
  
  • Endochondral = within cartilage

Question 39

intramembranous ossification

Answer 39

• Intramembranous – bone that forms from a fibrous membrane
  
  • intramembranous = inside membranes

Question 40

examples of bones that form from endochondral ossification

Answer 40

long and short bones, make up most of the axial and appendicular skeletons,

Question 41

examples of bones that form from intramembranous ossification

Answer 41

skull, flat bones, clavicle

Question 42

describe the role of the epiphyseal (growth) plate in the long bone

Answer 42

• The growth plate facilitates the growth of the long bones throughout childhood and adolescence until the body has reached its max height. Rapidly produces cartilage, is important in bone development, and once it reaches maturity the growth plate closes.

Question 43

the process of appositional growth

Answer 43

• The process by which bones increase in diameter by adding new bone tissue to the surface of the bone. (the osteoclasts work on the medullary cavity and the osteoblasts work on the outside)

Question 44

gigantism

Answer 44

when too much Growth Hormone is produced during childhood; which results in tall stature and poor health

Question 45

acromegaly

Answer 45

an overproduction of the growth hormone as an adult; results in larger than normal feet, hands, and even the face

Question 46

growth hormone deficiency

Answer 46

when too little growth hormone is produced during childhood; results in a small stature

Question 47

achondroplasia

Answer 47

without cartilage formation. When the head and torso are within normal range but the limbs are shortened

Question 48

bone tissue is?

Answer 48

innervated and vascularized