Skeletal System Flashcards
what are the components of the skeletal system
bones
cartilage
tendons
ligaments
it is the framework and gives shape to the body, support, and protects the internal organs
skeleton
what are the five functions of the skeletal system
body support
body movement
organ protection
blood cell production
mineral storage
[functions]
the skeleton supports the body against gravity
it largely determines the body’s shape
body support
[functions]
the skeleton is a system of muscle operated levers
body movement
[functions]
the bone is hard and protects the organs it surrounds
organ protection
[functions]
many long bones contain cavities filled with red bone marrow, a tissue that produces new red blood cells, white blood cells and platelets
the yellow bone marrow replaces the red bone marrow
blood cell production
[functions]
the bone stores calcium and phosphorus
if blood levels of these minerals decrease, the minerals are released from bone into blood
mineral storage
__________ __________ is also stored within bone cavities
if needed, the lipids are released into the blood and used by other tissues as a source of energy
adipose tissue
__________ are hard connective tissue forming the substance and structure of the skeleton
bones
the adult skeleton is composed of __________ bones
206 bones
bone destroying cells that break down the bone
osteoclasts
is the breakdown of bone and is important for mobilizing crucial calcium and phosphate ions for use in many metabolic processes
bone reabsorption or bone resorption
as bone is broken down, the __________ goes back into the blood
calcium
bone forming or bone building cells that produces collagen and secrete matrix vesicles that contain calcium and phosphate
osteoblasts
the formation of new bone by osteoblasts
ossification
it occurs by appositional growth on the surface of previously existing material, either bone or cartilage
ossification
__________ is produced by the osteoblasts covers the older bone surface and surrounds the osteoblast cell bodies and extensions
the result is a new layer of bone
bone matrix
the living protein matrix laid down by the osteoblasts
forms a living web-like protein matrix
bone collagen
provides scaffolding for bone formation
becomes mineralized to make bones strong and appear to be hard
bone collagen
mature bone cells accounting for 90% - 95% of bone cells and has a life span of 25 years
osteocytes
osteocytes are connected to neighboring osteocytes through their cell extensions: __________ and __________
lacunae
canaliculi
spaces between the bone matrix where osteocyte cell bodies are housed
lacunae
long narrow spaces where osteocyte cell extensions are housed
canaliculi
nutrients and gases pass through the small amount of fluid surrounding the cells in the __________ and __________ or pass from cell to cell through the gap junctions connecting the cell extensions
canaliculi and lacunae
has more bone matrix and less space than spongy bone
it is dense and looks smooth and homogenous making a solid outer layer surrounding each bone
compact bone
thin concentric sheets or layers of organized arrangement of collagen fibers approximately 3-7 micrometers thick
lamella
appears porous, has less bone matrix and more space than compact bone
it is composed of small needlelike pieces of bone and lots of open space
spongy bone
interconnecting rods or plates of bone found in spongy bone
between the __________ are spaces, filled with bone marrow and blood vessels
trabeculae
typically longer than they are wide
they have a shaft with heads at both ends
long bones
long bones are mostly __________ bone
compact bone
most of the bones of the __________ are long bones
upper and lower limbs
bone classification that are generally cube shaped
the wrist and ankle bones are examples
short bones
short bones contain mostly __________ bone
spongy bone
bones that are thin, flattened, and usually curved
flat bones
flat bones have two thin layers of __________ sandwiching a layer of __________ between them
compact bone
spongy bone
give examples of long bones
humerus, femur (any of the bones in the upper or lower limb)
give examples of short bones
wrist and ankle
give examples of flat bones
sternum, skull bones, ribs, shoulder blades
give examples of irregular bones
vertebra, facial bones
[structure of long bones]
the functional unit of a long bone
it is composed of concentric rings of matrix, which surround a central tunnel and contain osteocytes
osteon
[structure of long bones]
contains blood vessels, nerves, and loose connective tissue
this is surrounded by lamellae rings of bone matrix
central canal
[structure of long bones]
contains blood vessels and delivers blood to the central canals of the osteons
these run perpendicular to the length of the bone
volkmann canal
[structure of long bones]
the center portion of the bone and is composed primarily of compact bone
diaphysis
[structure of long bones]
a hollow center surrounded by the diaphysis
it is where red bone marrow and/or yellow bone marrow are stored
medullary cavity
site of blood cell formation
red bone marrow
adipose tissue for storage of fats
yellow bone marrow
[structure of long bones]
the ends of the long bones
these are mostly spongy bone, with an outer layer of compact bone
epiphysis
[structure of long bones]
it is located between the epiphysis and the diaphysis where growth in bone length occurs
epiphyseal plate
[structure of long bones]
the ossified epiphyseal plate resulting from the stopping of bone growth in length
epiphyseal line
[structure of long bones]
a connective tissue membrane covering the outer surface of a bone
the outer fibrous layer is dense irregular collagenous connective tissue that contains blood vessels and nerves
periosteum
[structure of long bones]
a single cell layer of connective tissue that lines the internal surfaces of all cavities within bones, such as the medullary cavity of the diaphysis and the smaller cavities in spongy and compact bone
endosteum
these bones have a composition similar to the epiphyses of long bones - compact bone surfaces surrounding a spongy bone center with small spaces that are usually filled with marrow
short and irregular bones
these bones are not elongated and have no diaphyses
however, certain regions of these bones, such as the processes, have epiphyseal growth plates and therefore small epiphyses
short and irregular bones
within some of the flat and irregular bones of the skull are air-filled spaces
sinuses
sinuses are lined by __________
mucous membranes
it is the process of replacing old bone with new bone
bone remodeling
__________ remove old bone and __________ deposit new bone
osteoclasts
osteoblasts
involved in several important functions, including bone growth, changes in bone shape, adjustment of the bone to stress, bone repair, and body calcium ion regulation
bone remodeling
bones are remodeled continuously in response to changes in two factors
calcium levels in the blood
pull of gravity and muscles on the skeleton
bones increase in size only by __________ which is the formation of new bone on the surface of older bone or cartilage
appositional growth
long bones and bony projections increase in length because of growth at the __________
epiphyseal plate
in a long bone, the epiphyseal plate separates the __________ from the ___________
epiphysis from the diaphysis
long bones grow by creating new cartilage via __________ in the epiphyseal plate
this is followed by __________ on the surface of the existing cartilage
interstitial growth
appositional bone growth
osteoblasts from the periosteum lay down bone beneath it to form a series of ridges with grooves between them, following appositional bone growth
bone width growth
as the osteoblasts continue to produce bone, the ridges __________, and meet to change the groove into a tunnel which is lined by the endosteum
increase in size, extend toward each other
bones located along the central axis of the body
axial skeleton
the axial skeleton consists of _____________
bones of the head, vertebral column, and rib cage
it also protects the brain, the spinal cord, and the vital organs housed within the thorax
axial skeleton
consists of the appendages and the bones that support them
appendicular skeleton
the appendicular skeleton is made up of __________
bones of the upper limbs, lower limbs, and the two girdles: pectoral and pelvic girdle
allows movement of appendages and supports weights in an upright position
appendicular skeleton
this bone is a small u-shaped bone that does not articulate with any other bone, connecting to its neghboring structures by muscles and ligaments
hyoid bone
this bone is located at the midline at the level of C3 providing stability to the adjacent structures and playing a critical role in the movement of the upper airway
hyoid bone
it is a continuous series of vertebrae separated by intervertebral discs
vertebral column
there are usually __________ vertebrae named according to their region: __________
33 vertebrae
cervical vertebrae, thoracic vertebrae, lumbar vertebrae, sacral vertebrae, and coccyx
how many bones are there in each region of the vertebrae
cervical vertebrae (7)
thoracic vertebrae (12)
lumbar vertebrae (5)
sacrum (5 fused) and coccyx (4 fused)
this bones is the lower part of your pelvis that is sometimes referred to as your sit bones
ischial tuberosity or ischium
it is the ilium’s top border, the largest of the three bones that make up the pelvis
iliac crest
an elastic band of tissue that connects bone to bone and provides stability to the joint
ligament
a band of tissue that connects muscle to bone
tendon
a soft, gel-like padding between bones that protects joints and facilitates movement
cartilage
most bones in the body start out as __________ model, growth in the bone length and and bone repair often involve making __________ first, then replacing it with bone
hyaline cartilage
hyaline cartilage that covers the ends of bones where they come together to form joints, has no blood vessels or nerves
articular cartilage
articulations holds the bones together securely but also give the rigid skeleton mobility
joint
these joint classifications focus on the amount of movement allowed by the joint
synarthroses
amphiarthroses
diarthroses
immovable joints
synarthroses
slightly movable joints
amphiarthroses
freely movable joints
diarthroses
these joint classifications are according to the major connective tissue type that binds the bones together and whether a fluid-filled joint capsule is present
fibrous joints
cartilaginous joints
synovial joints
are immovable and slightly movable joints connecting the bones with fibrous tissue
fibrous joints
the best example of these joints are the sutures of the skull
the irregular edges of the bones interlock and are bound together by connective tissue fibers allowing no movement to ocur
fibrous joints
are immovable and slightly movable joints connecting the bone ends with cartilage
cartilaginous joints
examples of this joint type are the intervertebral joints of the spinal column, where the articulating bone surfaces are connected by discs of fibrocartilage
cartilaginous joints
freely movable joints with bone ends are separated by a joint cavity containing synovial fluid
synovial joints
most joints that unite the bones of the appendicular skeleton are __________, reflecting the far greater mobility of the appendicular skeleton compared with the axial skeleton
synovial joints
serves as protection and lubrication to the joints
it reduces friction during movement
synovial fluid
describes the amount of mobility that can be demonstrated in a given joint
range of motion
it is the amount of movement that can be accomplished by contracting the muscles that normally act across a joint
active range of motion
it is the amount of movement that can be accomplished when the structures that meet at the joint are moved by an outside force
passive range of motion
