Skeletal system Flashcards
What are the two main functions of the skeleton system?
protection and support
What are the four complete functions of the skeleton system?
- protection/support
- aids in movement
- storage of minerals : Ca, P
- Hemopoiesis
What does “hemo-“ mean?
blood
What does “-poiesis” mean?
make more
What type of tissue is bone?
supporting connective tissue
What is another name for bone?
osseous
What four categories make up the skeletal systems?
bones, cartilage, ligaments, and tendons
Bones
rigidity; primary organs of the skeletal
Cartilage
- flexibility
- cushioning
Ligaments
connection of the skeletal components (bone to bone)
Tendons
attachment of muscles to the skeleton (muscle to bone)
What are the bone cells?
osteoprogenitors, osteoblasts, osteocytes, and osteoclasts
Osteoprogenitors
stem cells that generate osteoblasts
Osteoblasts
synthesize soft osteoid that later mineralizes while trapped in the bone matrix, osteoblasts differentiate (develop) into osteocytes
Osteocytes
maintain ECM regulate other bone cells
Osteoclasts
bone resorption = removal
What does “gen-“ mean?
generate
What does “-blasts” mean?
builder
What does “-cytes” mean?
mature cells
What does “-clasts” mean?
crusher
What are osteoids mostly made up of?
collagen
What is an identifying characteristic of osteocytes?
branches
The bone matrix is split into what two categories?
organic and inorganic
What are the organic structures in the bone matrix?
osteoids
What precent of osteoids are collagen?
90%
What is the function of osteoids in the bone matrix?
strength and some flexibility
What are the inorganic structures in the bone matrix?
minerals, primarily Ca3(PO4)4
What is the function of minerals in the bone matrix?
hardness
What is the result of collagen loss in the bone?
broken bones
What is the result of insufficient calcium?
soft bones
The bone matrix constantly goes under what processes?
bone formation and bone resorption
Bone formation is done by what cell?
osteoblasts
What are the two aspects of bone formation?
osteoids and mineralization
What does osteoids require?
vitamin C
What does mineralization require?
P, Ca, vitamin D
Bone resorption is done by what cell?
osteoclasts
What are the two aspects of bone resorption?
enzymes and HCL
What is the function of enzymes in bone resorption?
digest osteoids
What is the function of HCL in bone resorption?
dissolve Ca and P
What are the two types of bone tissue?
compact bone and spongy bone
What are the other names for compact bones?
dense and cortical
What are the units of compact bone?
osteons
What is another name for spongy bone?
trabecular
What are the units of spongy bone?
trabeculae
What features does spongy tissue provide?
- resistance but light weight
- spaces are filled with bone marrow
What do both compact and spongy bone contain?
vessels and nerves
What is the function of bone marrow?
hemopoiesis
What are the three sections of long bone?
Diaphysis, Epiphysis, and Metaphysis
Diaphysis
elongated shaft
Diaphysis function
leverage and major weight support
Diaphysis composition
- outer layer: compact bone
- inner layer: spongy bone
What cavity does the diaphysis cavity contain?
medullary cavity
Medullary cavity
houses red bone marrow
Epiphysis
knobby region at the ends of long bone
Epiphysis composition
- outer layer
- inner layer
- joint surface
Epiphysis outer layer is made of what?
compact bone
Epiphysis inner layer is made of what?
spongy bone
Epiphysis joint surface is covered by what?
articular cartilage
Metaphysis
region between diaphysis and epiphysis
The metaphysis section contains what plate?
epiphyseal plate
Epiphyseal plate
thin layer of hyaline cartilage that provides for lengthwise bone growth (till 25-26 years)
Epiphyseal line
remnant of epiphyseal plate in adults
What are the two kinds of bone linings?
periosteum and endosteum
Periosteum
cover the outer surface of bone
What are the two layers of periosteum?
fibrous and cellular
Fibrous layer of periosteum
protects; anchors vessels/nerves; attachment site for ligaments/tendons