Module 3: Bones and Articulations Flashcards
functions of bone/skeleton
- support
- protection
- allow movement/lever system
- storage depot for Ca and P salts
- hematopoiesis
hematopoiesis
forms blood cellular components from stem cells
what is the stem cell that forms blood called?
hematopoietic stem cells
bones that are longer than they are wide
long bones
bones that are as wide as they are long
short bones
bones that are flatter than they are round
flat bones
bones with an irregular shape
irregular bones
bones that form in the tendon, commonly found in the patella (kneecap)
sesamoid bones
shaft of long bones
diaphysis
neck of long bones, connects diaphysis and epiphysis
metaphysis
heads of long bones
epiphysis
center of the diaphysis, filled with yellow bone marrow
marrow cavity (red = active, yellow = inactive)
hard bone that forms the outer shell of long bones, contains osteons, concentric layers of lamellae, central canal in the middle with vessels and nerves
compact bone
component of long bone that forms a lattice like network of trabeculae which lighten the weight of the bone, also contains red bone marrow that would be found in the epiphysis
spongy bone
wrapping around the outside of long bones, consists of two layers (fibrous = outside, cellular = inside)
periosteum
inside the medullary cavity of long bones, contains osteoblasts and osteoclasts
endosteum
at the metaphysis of long bones, containing hyaline cartilage, known as the growth plate as it’s where bone formation occurs
epiphyseal plate
at about age 25, the hyaline cartilage at the epiphyseal plate of a long bone goes away leaving the
epiphyseal line
cartilaginous part of the long bone at the very end lining of the epiphysis, we have a layer of hyaline cartilage for cushioning the point where two bones articulate
articular cartilage
blood vessels enter the compact bone via
Volkmann’s canals
ossification
bone formation
when does ossification begin
early gestation when the fetal skeleton is formed
what is the name of the connective tissue that forms the fetal skeleton?
mesenchyme
what is mesenchyme?
a very vascular, connective tissue that contains many blood vessels, a large amount of collagen fibers, and forms the fetal skeleton
bone forms directly from mesenchyme, occurs mostly in flat bones
intramembranous ossification
large areas of dense connective tissue that provide flexibility during birth and growth
fontanelles
special type of joint between bones of the skull
sutures
most bones are first modeled as hyaline cartilage, and then starting 6-8 weeks after conception are converted to a calcified, hardened bone through this process
endochondral ossification
if hyaline cartilage is present at the epiphyseal plate, what is the bone still capable of?
increasing in length
does cartilage proliferation occur on the epiphyseal or diaphyseal side of the epiphyseal plate?
epiphyseal side
does ossification occur on the epiphyseal or diaphyseal side of the epiphyseal plate?
diaphyseal side
increasing bone width is which type of growth?
appositional growth
what is appositional growth?
adding layers, remodeling the marrow cavity, compact bones thickens and strengthens long bone with layers of circumferential lamellae, can occur in adults
during appositional growth, osteoclasts do what to the medullary cavity?
reabsorb bone to widen the medullary cavity, which also makes the bone wider
bone remodeling occurs in response to changes in what?
demand (force or load) on the bones
Wolff’s Law
bones remodel in response to compressive force
bones serve as a reservoir for which nutrient?
calcium
parathyroid hormone (PTH) stimulates
osteoclast activity and the reabsorption of calcium by our intestines and kidneys
PTH is released from the parathyroid gland in response to high or low calcium levels?
low, stimulates osteoclasts which breaks down bone calcium to be released to the bloodstream
calcitonin inhibits the activity of what, and stimulates the activity of what?
osteoclasts, osteoblasts
calcitonin is released by which gland, in response to what?
thyroid gland, high calcium levels
most common bone disease
osteoporosis
what causes osteoporosis?
as we age, osteoclast activity becomes faster than osteoblast activity
what is osteoporosis?
less bone density overall
symptoms of osteoporosis
fractures and decreases in calcium reserves
what is a change in the posture (shrinking) of a person as a result of tiny fractures caused by osteoporosis?
kyphosis
what does kyphosis look like?
stooped, exaggerated curvature of the spine
long term symptom of kyphosis
decrease in lung capacity
steps of bone repair after a fracture
- hematoma
- soft callus
- bony callus
- remodeling
bone break contained within the skin
closed fracture
bone break that breaks through the skin
open/compound fracture
bone does not break all the way through, happens in children because the bones aren’t fully developed
greenstick fracture
articulation (joint)
meeting place of 2 or more bones
range of motion (ROM)
refers to the normal extent of mobility for a specific joint movement
degrees of freedom (DOF)
the number of axes at which movement in a joint occurs
mobility and stability have what kind of relationship?
inverse
classification by structure categories
- fibrous
- cartilaginous
- synovial
classification by function categories
- synarthrosis: immovable
- amphiarthrosis: slightly movable
- diarthrosis: freely movable
movements that occur in the sagittal plane
- flexion (bends the joint, includes dorsiflexion)
- extension (straightens the joint, incudes plantarflexion)
movements that occur in the frontal plane
- abduction (movement way from midline)
- adduction (movement towards the midline)
movements that occur in the sagittal and frontal plane
circumduction (combination of movements in a cone-like shape)
movements that can occur around the longitudinal axis of the moving segment
rotation
rotation includes
- rotation of the head and neck
- rotation of the intervertebral joints of the spine
- rotations possible at ball-and-socket joints
special movements
- pronation (turns the wrist down)
- supination (turns the wrist up)
- inversion (bends the ankle inwards)
- eversion (bends the ankle outwards)
- protraction (push forward)
- retraction (pull backwards)
- pincer grasp (thumb touches any finger)
joint categories
structural and functional
when are fontanels ossified by?
2 years old
bones are connected by an interosseous ligament, allow slight shift, or “give” movement”
syndesmosis
hyaline cartilage connects bones or parts of bones, immovable, structure reveals developmental history
synchondrosis
fibrocartilage discs unite bones, allows slight movement between articulating bones
symphysis
characterized by a joint cavity containing synovial fluid, freely movable joints, most common joint in appendicular skeleton, all share common anatomy
synovial joint
function of synovial fluid
- cushion
- lubricate
- nourish
“pillow” filled with synovial fluid
bursa
“sleeve” filled with synovial fluid
tendon sheath
uniaxial joints
hinge and pivot
features of uniaxial joints
1 axis of rotation, 1 plane of movement, 1 movement pair
biaxial joints
condyloid and saddle
features of biaxial joints
2 axes of rotation, 2 movement pairs (flexion/extension, abduction/adduction, PLUS circumduction)
triaxial joints
ball-and-socket
features of ball-and-socket joints
- 3 axes of rotation
- movement pairs
—– flexion/extension
—– abduction/adduction - rotations
—– medial
—– lateral
—– +combined movement circumduction
nonaxial joints
gliding
features of gliding joints
no identifiable axes of rotation and slight gliding movements
