skeletal system

Question 1

sesamoid bones 1. shape 2. begin as what 3. form where and when

Answer 1

1. seed-shaped 2. start as bone spurs 3. form w/in joints throughout life

Question 2

articular cartilage 1. location 2. made of what

Answer 2

1. surrounds the ends of long bones 2. made of hyaline cartilage

Question 3

periosteum

Answer 3

membrane that covers all bones

Question 4

endosteum

Answer 4

lining of medullary cavity

Question 5

3 bone cell types

Answer 5

1. osteoblasts 2. osteocytes 3. osteoclasts

Question 6

osteoblasts

Answer 6

immature bone cells that make new bone tissue (grow and repair bone)

Question 7

osteocytes

Answer 7

mature osteoblast that are trapped in the bone matrix and maintain it

Question 8

osteoclasts 1. break down what 2 things 2. by what means

Answer 8

1. break down bone tissue and other types of connective tissue 2. by releasing calcium from bone into blood

Question 9

osteons

Answer 9

structural units of compact bone tissue

Question 10

central canal 1. location 2. three contents

Answer 10

1. cavity running down the middle of osteon 2. blood vessels, nerves, lymphatic vessels

Question 11

lamellae

Answer 11

concentric rings of bone tissue matrix around central canal

Question 12

lacunae

Answer 12

spaces between lamellae each containing an osteocyte

Question 13

canaliculi

Answer 13

tiny canals connecting neighboring lacunae

Question 14

bone tissue matrix 1. ground substance and it’s affects 2. protein fibers and their affect

Answer 14

1. calcium crystals which make bones hard and resistant to compression 2. collagen protein fibers which make bones bendable but resistant to stretching

Question 15

how long bones grow in length on the epiphysis side of epiphyseal plate (something constantly dividing)

Answer 15

cartilage cells are constantly dividing and making new cartilage which lengthens the diaphysis

Question 16

how long bones grow in length on diaphysis side of epiphyseal plate (remove something from where and replace w/ what)

Answer 16

osteoclasts and osteoblasts remove the old cartilage of the epiphyseal plate and replace it with spongy bone tissue

Question 17

how long bones grow in width externally

Answer 17

cells in periosteum form new osteoblasts which form osteocytes (new compact bone)

Question 18

how long bones grow in width internally

Answer 18

endosteum forms osteoclasts which break down wall of medullary causing it to expand

Question 19

how non-long bones grow larger externally

Answer 19

cells in periosteum form new osteoblasts which form osteocytes (new compact bone)

Question 20

how non-long bones grow larger internally

Answer 20

endosteum forms osteoclasts and osteoblasts which replace compact bone tissue with spongy bone tissue

Question 21

3 hormones that control bone growth

Answer 21

1. human growth hormone HGH 2. testosterone 3. estrogen

Question 22

3 steps of how the epiphyseal plate turns into the epiphyseal line

Answer 22

1. testosterone/estrogen reach adult levels which stimulates the epiphyseal plate to close 2. the cartilage cells die 3. the plate is converted to compact bone which forms the line

Question 23

pituitary dwarfism

Answer 23

pituitary gland doesn’t produce enough HGH (affects all bones)

Question 24

achondroplasia dwarfism

Answer 24

epiphyseal plates in long bones don’t respond well to HGH

Question 25

bone remodeling

Answer 25

restructuring/restrengthening of bones occurs throughout life

Question 26

2 types of bone remodeling

Answer 26

1. bone deposition 2. bone resorption

Question 27

bone deposition 1. is what 2. occurs when 3. what secretes what that stimulates production of what

Answer 27

1. bone tissue added to bone making them denser and stronger 2. occurs when thyroid gland senses high blood calcium levels (caused by consuming calcium) 3. thyroid gland secretes calcitonin (hormone that stimulates production of osteoblasts) which returns blood calcium levels to normal

Question 28

bone resorption 1. is what 2. occurs when 3. what secretes what that stimulates production of what

Answer 28

1. bone tissue is broken down making the bone less dense and weaker 2. occurs when parathyroid glands sense low blood calcium levels (caused by not consuming calcium) 3. parathyroid glands secrete parathyroid hormone (stimulates production of osteoclasts) which returns blood calcium levels to normal

Question 29

blood calcium level dictates what

Answer 29

whether bone deposition or bone reposition is occurring on our skeleton

Question 30

Wolff’s law

Answer 30

1. bone deposition is targeted to bones and regions of bones experiencing more weight and physical stress 2. bone reposition is targeted to bones and regions of bones where there’s a lack of weight and stress

Question 31

4 stages of bone fracture repair

Answer 31

1. blood clot forms in fracture site 2. connective tissue cells (fibroblasts, chondroblasts, osteoblasts) enter fracture site forming connective tissue callous 3. osteoblasts and osteoclasts replace connective tissue callous w/ spongy bone 4. osteoblasts and osteoclasts remodel spongy bone into compact bone tissue

Question 32

rickets

Answer 32

occurs in children due to lack of calcium and/or vitamin D and causes deformed and brittle bones

Question 33

osteomalacia

Answer 33

“adult rickets” occurs in adults due to lack of calcium and/or vitamin D and causes brittle and painful bones

Question 34

osteoporosis 1. are what and lead to what 2. due to what 3. considered what

Answer 34

1. porous/brittle bones leading to bone fractures 2. due to bone resorption out pacing bone deposition 3. considered to be a normal part of aging

Question 35

11 risk factors for osteoporosis

Answer 35

1. age 2. low calcium/vitamin D diet 3. certain meds 4. being female 5. asian or european ancestry 6. petite frame 7. sedentary lifestyle 8. family history 9. smoking 10. alcoholism 11. consuming phosphates