Unit 3 skeletal system Flashcards
5 functions of the skeletal system
- provide structure, support and protection 2. essential for locomotion and movement 3. site of blood cell formation (hematopoiesis) 4. storehouse for some inorganic materials, especially calcium 5. indicator of sex, height, age, weight, race and medical history
a bone that is longer than wide, cylindrical with a medullary cavity
long bones
this bone is the main component of limbs
long bones
this bone is roughly cubical and found where mobility is needed but space is limited
short bones
carpals and tarsals are examples of this type of bone
short bones
this is a relatively thin bone that provide broad surfaces for muscle attachment and/or protection of the underlying organs
flat bones
frontal, parietal, innominate, ribs and scapula are all examples of
flat bones
this type of bone is the main site of blood cell formation in adults
flat bones
these bones are abnormal shaped with numerous projections
irregular bones
sphenoid, ethmoid and scapula are examples of this type of bone
irregular bones
these bones contain sizable air spaces and are only found in the skull
pneumatic bones- all the sinuses
these bones reduce the weight of the skull thus reducing the need for large neck muscles
pneumatic bones
frontal, maxilla, sphenoid, ethmoid, mastoid process bones are all examples of what type of bone?
pneumatic bones
what bones are small, round and embedded within a tendon
sesamoid bones
sesamoid bones alter what?
the angle of muscle attachment to increase mechanical leverage
patella is an example of what type of bone?
sesamoid bone
bones of the skull, hyoid, vertebral column and rib cage are all part of the________
axial skeleton
bones of the limbs and their attachment onto the axial skeleton are part of the?
appendicular skeleton
pectoral and pelvic girdles are part of what part of the skeleton?
appendicular skeleton
bones of the skull are also called
the cranial skeleton
bones of the vertebral column, hyoid, rib cage, limbs, pectoral girdle and pelvic girdle are all examples of bones in the
post-cranial skeleton
bone matrix fibers are what type of fibers and what is there function?
they are collagen type I fibers and they provide strength to resist tension
organic components of the ground substance of the bone matrix include
proteoglycans and glycoproteins
as a review, what are the 3 main examples of proteoglycans?
chondroitin sulfate, keratan sulfate and hyaluronic acid
what are 2 types of glycoproteins in the bone matrix
osteonectin and osteocalcin
what is the inorganic component of the ground substance of the bone matrix?
hydroxyapatite
what is an inorganic mineral composite which provides strength to resist compressive forces?
hydroxyapatite
organic and inorganic components of the ground substance of the bone matrix are also called
osteoids
what type of bone cells give rise to or mature into osteoblasts
osteoprogenitor cells
what type of bone cells are located within the central and perforating canals of osteons and within the periosteum and endosteum?
osteoblasts
which type of bone cell is responsible for laying down new bone tissue and mature into osteocytes?
osteoblasts
what are mature osteoblasts located within the lacunae of the osteons of compact bones and also bony struts of spongy bone?
osteocytes
what are located in bony struts of spongy bone?
osteocytes
what are located in the lacunae of the osteons of compact bones?
osteocytes
which bone cell is responsible for maintaining surrounding bone tissue and regulating mineral content of the bone?
osteocytes
which are the bone destroying cells that digest organic components? also resorption
osteoclasts
these bone cells are large and multinucleated and originate from the fusion of several monocytes
osteoclasts
type of bone tissue described as a woven bone
primary bone tissue- immature
this bone tissue develops first during fetal development and is also associated with repair of fractures
primary bone tissue
primary bone is described as woven bone because of the
collagen fibers that are randomly arranged
primary/woven bone differs from mature bone how? 2 major differences
- mineral content is lower 2. contains more osteocytes
another name for secondary bone tissue?
mature or lamellar bone
3 categories of secondary bone tissue
compact/cortical bone spongy bone subchondral bone
the outer layer of densely packed bone tissue composed of osteons, circumferential lamellae and interstitial lamellae
compact/cortical bone
osteons are formations from
mature bone tissues
concentric layers of bone tissue are also called
lamellae
the fundamental functional unit of a mature bone and is also called
osteon; haversion system
within each layer of lamellae, collagen fibers are
oriented at right angles to the fibers in adjacent layers
open circle of the osteon that contains vascular structures and nerves
central or haversion canal
which part of the osteon is lined with osteoprogenitor cells and osteoblasts
central canal
which part of the osteon are the holes found between lamellae that contain osteocytes?
lacunae
which part of the osteon are passageways connecting lacunae to eachother and to the central and perforating canals
canaliculi
which part of the osteon connects the central canals to eachother and are also lined by osteoprogenitor cells and osteoblasts
perforating canals
what is another name for perforating canals?
communicating or volkmann’s canals
multiple layers of mineralized matrix of secondary bone tissue is called?
circumferential lamellae
the external circumferential lamellae is located deep to the_______
periosteum
the inner circumferential lamellae is located at the
perimeter of the medullary cavity
this is also layers of the mineralized matrix of bone tissue but its different in that it lies between and around osteons and is made up of partially destroyed osteons
interstitial lamellae
other names for spongy bone
cancellous or trabecular bone
where is spongy bone found?
in the interior of a bone
a lattice of bony bars and struts is also called
trabeculae
each trabeculae consists of a few concentric layers of
bony connective tissue
the site of blood cell manufacturing in spongy bone
trabeculae
a type of secondary bone tissue with a very thin layer of modified compact bone, lacking the extensive vascular channels
subchondral bone
type of secondary bone tissue found underlying articular cartilage, making up the articular surface
subchondral bone
a type of abnormal bone growth from existing normal bone
accessory bone
an example of accessory bone abnormal growth would be
bone spurs
a type of abnormal bone growth formed entirely within soft tissue
heterotopic bone
examples of heterotopic bone
kidney stones, gallstones, muscle of tendon calcification
what is the name of the bone shaft where primary ossification occurs?
diaphysis
what part of a bone is often associated with an area of articulation with another bone or site of excessive muscle tension
epiphysis
where does secondary ossification occur?
epiphysis
what part of a bone connects the diaphysis and epiphysis and is composed of hyaline cartilage?
epiphyseal plate
what is the fibrous structure covering the outer surface of a bone; with exception to articular bone surfaces and where tendons and ligaments attach to a bone?
periosteum
what areas of bone does that periosteum not cover?
articular bone surfaces and where tendons and ligaments attach onto bone
the periosteum is anchored to outer bone surfaces by ?
perforating sharpey’s fibers
the periosteum consists of what 2 layers?
fibrous layer and cellular layer
the layer of periosteum that is superficial and consists of a sheet of dense irregular connective tissue
fibrous layer
the fibrous layer of the periosteum’s sheet of connective tissue contains type 1 collagen fibers, fibroblasts and what 2 other structures?
blood vessels and nerve fibers
what is the deep thin layer of the periosteum containing bone cells?
cellular layer
what type of bone cells does the cellular layer of the periosteum contain?
primarily osteoprogenitor cells and osteoblasts
what part of the bone is a very thin layer of connective tissue covering inner bone surfaces?
endosteum
the endosteum primarily consists of?
a single layer of osteoprogenitor cells and osteoblasts
what is the cavity at the center of the long bone called?
medullary cavity
Another name for medullary cavity
marrow cavity
in children, the medullary cavity is an additional site for
blood cell manufacturing
ie ‘red bone marrow’
in adults, the medullary cavity is a site for
adispose storage
ie ‘yellow bone marrow’
what part of bone covers articular surfaces and is composed of hyaline cartilage?
articular cartilage
a bone remodels its shape according to the way force is transmitted through it
Wolff’s law
intramembranous bone aka dermal bone are
bones at the top of the skull and the clavicle
endochondral bone aka cartilaginous include
bones of the skull base, all postcranial bones and part of the clavicle
describe the first 4 steps of the ontogenetic (development, morphogenesis) process in endochondral bone
- cartilaginous model forms
- cartilage disintegrates
blood vessels invade,
undifferentiated mesenchymal cells
- mesenchymal cells differentiate
into osteoprogenitor cells
then osteoblasts
form spongy bone
- periosteum forms
osteoblasts form compact bone
growth between the epiphysis and diaphysis is called
interstitial growth
the ends of bone where blood vessels invade in endochondral bone growth are the?
secondary ossification centers
secondary ossification centers are also called
epiphyses
what is the zone of cartilage remaining between primary and secondary ossification centers and is also the site of active growth?
epiphyseal plate
when a plate ossifies what ceases?
growth
what type of growth is an increase in overall size?
appositional growth
in appositional growth, new compact bone is deposited by osteoblasts just below the?
periosteum
which glycoprotein is involved with binding and connecting the mineral component of the ground substance to ground fibers??
osteonectin
which glycoprotein facilitates the mineralization of the ground substance?
osteocalcin
what is hydroxyapatite made of?
a mineral composite made of calcium phosphate and calcium carbonate
where are osteoprogenitor cells located?
in the cellular layer of the periosteum and endosteum
where are osteoblasts located?
within the central and perforating canals of osteons and within the periosteum and endosteum
what do osteoblasts originate from?
osteoprogenitor cells
where does the ontogenic process of the intramembranous bone take place?
takes place in a membrane layer formed by mesenchymal cells
what is vitamin D responsible for in the body?
- facilitates proper bone mineralization by increasing absorption of calcium w/in the Si
- reabsorption of calcium from the blood in the kidneys
what is on the outside of the intramembranous bone?
periosteum
the outside osteoblasts of the periosteum manufacture compact bone toward?
the outer edge
what does Vit D deficieny lead to?
rickets in children and osteomalacia in adults
what is the active form of vit D?
1,25-dihydroxycholecalciferol
what is the job of the parathyroid hormone?
it increases the amount of calcium in the body by indirectly stimulating osteoclast activity
when PTH binds to receptors on the osteoblasts, what is released?
osteoprotegerin ligand is released OPGL
when OPGL activates receptors on the preosteoclast cells what happens?
the preosteoclasts mature into osteoclasts
what does excess of PTH lead to?
bone thinning
what is a comminuted fracture?
complete and fragments the bone as well as interrupting blood supply
what is a greenstick fracture?
an incomplete fracture that happens in children; bone breaks on convex portion of bone but not on concave portion
what is a compression fracture?
forces cause bone to collaps and stack up on eachother
the healing process of a fracture:
- fracture hematoma forms from ruptured blood vessels
- soft callus forms (mix of spongy bone and cartilage)
- hard callus forms by mineralization and remodeling of soft callus
- remodeling of hard callus to mature (compact or spongy bone)
what is osteitis?
inflammation of bone tissue caused by injury or infection
what is periostitis?
inflammation of the periosteum caused by trauma or infection
what is osteomyelitis?
inflammation of bone interior caused by bacteria, usually entering bone via wound or bloodstream
How can TB spread and what is the result?
can spread to the spongy bone (particularly verterbral bodies) Potts disease and results in bone and joint destruction
what are neoplasms?
tumors
what are 2 types of benign tumors?
osteochondroma
osteoma
what are 2 types of malignant tumors?
osteogenic sarcoma
multiple myeloma
