Bone Physiology

Question 1

yellow bone marrow

Answer 1

fat storage tissue, mainly found in long bones

newborns don’t have any yellow bone marrow - overtime, convert some red bone marrow to yellow bone marrow

Question 2

red bone marrow

Answer 2

primarily produces red blood cells
mainly found in short & flat bones
newborns only have red bone marrow

Question 3

medullary

Answer 3

bone marrow cavity that extends throughout diaphysis

Question 4

diaphysis

Answer 4

center length of bone

Question 5

spongy bone

Answer 5

layer surrounding medullary, thickest at ends of bone
contains many bony bar and plates (which follow stress lines) separated by irregular spaces
lighter than compact bone but still strong

Question 6

proximal epiphysis & distal epiphysis

Answer 6

thick layers of spongy bone at each end of the bone

Question 7

compact bone

Answer 7

solid outer layer of bone

contains many osteons

Question 8

osteons

Answer 8

contain osteocytes within tiny lacunae

lacunae arranged in concentric circles around center canals, separated by matrix

Question 9

osteocytes

Answer 9

bone cells, found w/in osteons

Question 10

lacunae

Answer 10

tiny chambers within osteons that hold osteocytes

Question 11

center canals

Answer 11

canals within osteons that contain blood vessels & nerves
bring nutrients for the bone to renew itself

Question 12

matrix

Answer 12

network of collagen protein fibers & mineral deposits (mainly Calcium + Phosphorus salts) that separates lacunae

Question 13

osteoclasts

Answer 13

bone absorbing cells

break down bone, remove worn cells, and deposit Calcium into blood

Question 14

osteoblasts

Answer 14

repair osteoclasts’ damage

form new bone by taking Ca from blood

Question 15

osteocyte formation

Answer 15

when osteoclasts or osteoblasts get stuck in the matrix, they are converted into osteocytes and become new bone tissue)

Question 16

prenatal bone development

Answer 16

in fetus, most bones are cartilaginous structures in the shape of future bones

Question 17

ossification

Answer 17

process of converting cartilaginous models of bones into bone - Ca salts are deposited into the matrix by precursor cartilaginous cells and then by osteoblasts

Question 18

endochondrial ossification

Answer 18

ossification of long bones from hyaline cartilage

• starts within primary ossification structure in middle of bone
• cartilage cells begin dying, so blood vessels penetrate the bone to deliver osteoblasts
• this forms that medullary cavity + secondary centers form at ends of bone
• cartilaginous disk (growth plate) remains between primary + each secondary center until completely ossified during puberty –> bone stops growing, reaches full adult height

Question 19

intramembranous ossification

Answer 19

formation of fetal bones from connective tissue (occurs during different parts of embryonic dev)

• starts with mesenchymal cells differentiating into osteoblasts
• osteoblasts secrete bone tissue
• once secrete enough bone tissue, osteoblasts become osteocytes