skeletal system

Question 1

functions of bones

Answer 1

1. support
2. protection
3. helps with movement
4. stores minerals
5. stores energy
6. produces blood cells

Question 2

types of bones

Answer 2

• long bones: made of cortical (compact) bone
• short bones: as wide as long, mainly provide support
• flat bones: provide protection (skull)
• rregular bones: irregular shaped

Question 3

epiphysis

long bone component

Answer 3

• end of long bone
• forms joints with other bones
• red bone marrow for hemtopoiesis (making RBCs)

Question 4

diaphysis

long bone component

Answer 4

long, hollow shaft

Question 5

medullary cavity

long bone component

Answer 5

within diaphysis, contains yellow and red marrow (fat storage)

Question 6

metaphysis

long bone component

Answer 6

between epiphysis and diaphysis

Question 7

epiphyseal plate

long bone component

Answer 7

• “growth plate”
• hyaline cartilage –> lengthens diaphysis in growth and ossification

Question 8

cortical bone

Answer 8

• dense outer layer of bone
• supports weight of body

Question 9

osteons

cortical bone component

Answer 9

functional unit

Question 10

haversian canals

cortical bone component

Answer 10

“tubes” that contain blood vessels for nutrient supply

Question 11

lamellae

cortical bone component

Answer 11

layers of osteon

Question 12

lacunae

cortical bone component

Answer 12

spaces between lamellae and interconnect through canaliculi

Question 13

canaliculi

cortical bone component

Answer 13

small channels that connect lacunae and haversian canals

Question 14

volkmann’s canals

cortical bone component

Answer 14

connect Haversian canals to periosteum + provide nutrients

Question 15

cancellous (spongy) bone

Answer 15

inner layer, soaks up red bon marrow via a web of trabeculae (CT that supports spongy bone)

Question 16

bone remodeling

Answer 16

process of going back and forth between ossification (bone formation) and resorption (bone loss)

Question 17

osteoprogenitors

Answer 17

immature precursor cells that differentiate into osteoblasts

Question 18

osteoblasts

Answer 18

build bone around themselves, then mature into osteocytes once trapped in the bone matrix they created
* utilize Ca++ in blood to build bone

Question 19

osteocytes

Answer 19

differentiaited osteoblasts, help exchange nutrients/waste with blood
* live in lacunae in osteons to maintain bone

Question 20

osteoclasts

Answer 20

CRUSH or resorb bone, similar in structure to WBCs
* release Ca++ and phosphate into blood
* derived from monocytes

Question 21

increase in Ca++ levels

Answer 21

calcitonin decreases osteoclast activity allowing osteoblasts to build bone
* this decreases Ca++ blood levels

Question 22

decrease in Ca++ levels

Answer 22

• PTH stimulates osteoclasts relaeasing Ca++ therefore increase [Ca++] in blood
• vitamin D also increase Ca++ levels in blood by increasing intestinal Ca++ absorption
• PTH activates vitamin D

Question 23

hydroxyapatite

Answer 23

mineral that forms bone containing Ca and PO4
* building/breaking down bone will decrease/increase blood Ca++ and HPO4- levels
* main component in enamel

Question 24

intramembranous ossification

embryonic ossification

Answer 24

• mainly for flat bone (bones of skull except base and facial bones) and clavicle
• woven bone is formed directly without cartilage —> remodeled later to lamellar bone

Question 25

endochondral ossification

embryonic ossification

Answer 25

• mainly for long bones (axial and appendicular skeletal) + base of skull
• cartilage models made by chondrocytes –> calcifies during fetal development and creates ossification centers
• osteoclasts and blasts replace it with woven bone –> then later lamellar bone

Question 26

types of connective tissue

Answer 26

• loose
• adipose
• blood
• fibrous
• bone