BIO 161 - PSU - EXAM 5 QUESTIONS AND ANSWERS
A+ GRADED
Skeletal System
dynamic system of connective tissue (balance between production and remodeling)
Function Of Bones
support, protection, movement, electrolyte balance, blood cell differentiation
(hematopoiesis)
Types Of Bone Shapes
flat, short, long, irregular, sesamoid, wormian
Sesamoid Bone
small bones embedded within tendon where it passes over a joint (patella)
Wormian Bone
extra irregularly shaped bone pieces that occur within a suture in the cranium
Infant vs. Adult Bones
humans are born with 300 bones, adults have 206 bones, much cartilage we have as
babies form into bone and as we grow those bones fuse together
Diaphysis
shaft of a long bone
Epiphysis
end of a long bone
Metaphysis
where diaphysis and epiphysis meet
Medullary Cavity
cavity within the shaft of the long bones filled with bone marrow
Endosteum
connective tissue lining the medullary cavity, contains osteogenic cells
Periosteum
thick layer of connective tissue covering bone. osteogenic cells and blood vessels that
nourish or help with repairs
Articular Cartilage (hyaline)
covers joint to reduce friction and absorb shock (place where bone articulates with
another to form joint)
Red Marrow
found at epiphysis of long bones & spongey bones, site for hematopoiesis
Yellow Marrow
stores fat
Bone Matrix Composition
>50% ground substance (hydroxyapatite), >25% collagen fibers (flexibility), >25% water
Calcification Mineralization
occurs when minerals (mostly calcium) are deposited around the collagen fibers
Compact Bone
(cortical) hard dense bone, usually forms the outer membrane and walls of bone
, Spongey Bone
(trabecular) contains spaces that are filled with blood forming tissue, usually on the
inside of bone
Osteoprogenitor Cells
stem cells that make osteoblast and osteocytes, divide to replace themselves or
produce osteoblast (found in periosteum and endosteum)
Osteoblast
some mature into osteocytes, but they secrete unmineralized bone matrix (osteoid),
which is collagen, calcium binding proteins
Osteocytes
mature bone cells, help maintain matrix, act as stress/strain sensors, communicates
with other bone cells to regulate growth and resorption
Lacunae
small cavities in bone that contain osteocytes
Osteoclast
derived from same stem cells that become white blood cells, large multinucleate cells,
responsible to bone resorption (destruction)
Canaliculi
small canals between lacunae, supplies nutrients and removes cell bone waste, also
aids in communication
Haversian Canal
canal through middle of osteons containing capillaries
Lamellae
extracellular matrix around cells that gives compact bone it's hardness
Volksman Canal
small channels that transmit blood vessels from periosteum into bone
Resting Zone (inactive)
chondrocytes on epiphyseal side relatively inactive
Proliferation Zone (1)
cells of diaphysis side stack & undergo rapid mitosis
Hypertrophic Zone (2)
older chondrocytes enlarges and lacunae erode
Calcification Zone (3)
calcified matrix invades diaphysis
Ossification Zone (4)
new empty space allows osteoblast to deposit bone as osteoclast erode cartilage
Histology Of Spongy Bone
no true osteons, made of trabeculae , contains lamellae & bone cells
Trabeculae
lattice of struts, surrounded by marrow
Histology Of Compact Bone
osteons are the structural components of CB, onion-like layers surrounding a central
canal, found within shafts of long bones & the covering of all bones
Why Are Osteons Aligned With Compressive Forces?
osteons align with stress lines to provide bone strength, they can change over time as
forces change
A+ GRADED
Skeletal System
dynamic system of connective tissue (balance between production and remodeling)
Function Of Bones
support, protection, movement, electrolyte balance, blood cell differentiation
(hematopoiesis)
Types Of Bone Shapes
flat, short, long, irregular, sesamoid, wormian
Sesamoid Bone
small bones embedded within tendon where it passes over a joint (patella)
Wormian Bone
extra irregularly shaped bone pieces that occur within a suture in the cranium
Infant vs. Adult Bones
humans are born with 300 bones, adults have 206 bones, much cartilage we have as
babies form into bone and as we grow those bones fuse together
Diaphysis
shaft of a long bone
Epiphysis
end of a long bone
Metaphysis
where diaphysis and epiphysis meet
Medullary Cavity
cavity within the shaft of the long bones filled with bone marrow
Endosteum
connective tissue lining the medullary cavity, contains osteogenic cells
Periosteum
thick layer of connective tissue covering bone. osteogenic cells and blood vessels that
nourish or help with repairs
Articular Cartilage (hyaline)
covers joint to reduce friction and absorb shock (place where bone articulates with
another to form joint)
Red Marrow
found at epiphysis of long bones & spongey bones, site for hematopoiesis
Yellow Marrow
stores fat
Bone Matrix Composition
>50% ground substance (hydroxyapatite), >25% collagen fibers (flexibility), >25% water
Calcification Mineralization
occurs when minerals (mostly calcium) are deposited around the collagen fibers
Compact Bone
(cortical) hard dense bone, usually forms the outer membrane and walls of bone
, Spongey Bone
(trabecular) contains spaces that are filled with blood forming tissue, usually on the
inside of bone
Osteoprogenitor Cells
stem cells that make osteoblast and osteocytes, divide to replace themselves or
produce osteoblast (found in periosteum and endosteum)
Osteoblast
some mature into osteocytes, but they secrete unmineralized bone matrix (osteoid),
which is collagen, calcium binding proteins
Osteocytes
mature bone cells, help maintain matrix, act as stress/strain sensors, communicates
with other bone cells to regulate growth and resorption
Lacunae
small cavities in bone that contain osteocytes
Osteoclast
derived from same stem cells that become white blood cells, large multinucleate cells,
responsible to bone resorption (destruction)
Canaliculi
small canals between lacunae, supplies nutrients and removes cell bone waste, also
aids in communication
Haversian Canal
canal through middle of osteons containing capillaries
Lamellae
extracellular matrix around cells that gives compact bone it's hardness
Volksman Canal
small channels that transmit blood vessels from periosteum into bone
Resting Zone (inactive)
chondrocytes on epiphyseal side relatively inactive
Proliferation Zone (1)
cells of diaphysis side stack & undergo rapid mitosis
Hypertrophic Zone (2)
older chondrocytes enlarges and lacunae erode
Calcification Zone (3)
calcified matrix invades diaphysis
Ossification Zone (4)
new empty space allows osteoblast to deposit bone as osteoclast erode cartilage
Histology Of Spongy Bone
no true osteons, made of trabeculae , contains lamellae & bone cells
Trabeculae
lattice of struts, surrounded by marrow
Histology Of Compact Bone
osteons are the structural components of CB, onion-like layers surrounding a central
canal, found within shafts of long bones & the covering of all bones
Why Are Osteons Aligned With Compressive Forces?
osteons align with stress lines to provide bone strength, they can change over time as
forces change
