Skeletal System

Question 1

two types of skeletons:

Answer 1

exoskeletons

endoskeletons

Question 2

exoskeletons

Answer 2

usually found in arthropods (insects)
encase whole organisms
must be shed and refrain to accommodate growth

Question 3

endoskeletons

Answer 3

found in vertebrates (humans)

are internal but are not able to protect the soft tissue structures as well as exoskeletons

Question 4

axial skeleton

Answer 4

skull, vertebral column, ribcage, and hyoid bone

provide central framework for the body

Question 5

appendicular skeleton

Answer 5

bones of limbs, pectoral girdle and pelvis

Question 6

the skeleton is created from two major components:

Answer 6

bone and cartilage

Question 7

bone strength come from

Answer 7

compact bone - both dense and strong

Question 8

spongy or cancellous bone

Answer 8

latice structure is visible under the microscope

consists of bony spicules (points) known as trabeculae

Question 9

bone marrow

Answer 9

found in the cavities between trabeculae

may be red or yellow

Question 10

Red marrow

Answer 10

filled with hematopoietic stem cells which are responsible for generation of all the cells in our blood

Question 11

Yellow marrow

Answer 11

composed primarily of fat and is relatively inactive

Question 12

long bones contain shafts called

Answer 12

diaphyses that flare to form metaphases and that terminate in epiphyses. The epiphysis contains an epiphyseal (growth) plate that causes linear growth of the bone

Question 13

bone is surrounded by a layer of connective tissue called

Answer 13

periosteum (site for muscle attachment)

Question 14

bones are attached to

Answer 14

muscles by tendons and each other by ligaments

Question 15

bone matrix

Answer 15

has both organic components like collagen, glycoprotein and other peptides and inorganic components like hydroxyapatite

Question 16

bone is organized into concentric rings called

Answer 16

lamellae around a central Haversian or Volkmann’s canal

this structural unit is called an osteon or Haversian system

Question 17

between lamellar rings are

Answer 17

lacunae

where osteocytes reside which are connected with canaliculi to allow for nutrient and waste transfer

Question 18

bone remodeling is carried out by

Answer 18

osteoblasts and osteoclasts

Question 19

osteoblasts

Answer 19

build bone

Question 20

osteoclasts

Answer 20

resorb bone

Question 21

parathyroid hormone

Answer 21

increases resorption of bone, increasing calcium and phosphate concentrations in the blood

Question 22

vitamin D

Answer 22

increases resorption of bone, leading to increased turnover and the production of stronger bone

Question 23

Calcitonin

Answer 23

increases bone formation, decreasing calcium concentrations in the blood

Question 24

cartilage is a firm elastic material secreted by

Answer 24

chondrocytes

its matrix is called chondrin

Question 25

Cartilage

Answer 25

found in areas that require more flexibility or cushioning

is avascular and is not innervated

Question 26

in fetal life, bone forms cartilage through

Answer 26

endochondral ossification

some bones form directly from undifferentiated tissue (mesenchyme) in intramembranous ossification

Question 27

joints may be classified as

Answer 27

immovable or movable

Question 28

immovable joints

Answer 28

are fused together to form sutures or similar fibrous joints

Question 29

movable joints

Answer 29

are usually strengthened by ligaments and contain a synovial capsule

Question 30

synovial fluid

Answer 30

secreted by the synovium

aids motion buy lubricating the joint

Question 31

each bone is coated with

Answer 31

articular cartilage to aid in movement and provide cushioning

Question 32

muscles that serve opposite functions come in

Answer 32

antagonistic pairs; when one muscle contracts, the other lengthens

Question 33

muscles that serve same functions :

Answer 33

synergistic