Cartilage bone and articulations Flashcards
diaphysis
the shaft of the bone
epiphysis
the end of the bone
metaphysis
the narrow region where the diaphysis connects to the epiphysis
cartilage
- this is primarily made of water
- avascular
- gets nutrients from diffusion
chondroblasts
cartilage building cells
chondrocyte
mature cartilage cell
perichondrium
-this is the outer layer of cartilage that resists outward pressure
hyaline cartilage
- the most common type of cartilage
- provides stiff but somewhat flexible support
- contains closely packed collagen fibers
where can hyaline cartilage be found
- between the tips of the ribs and the sternum
- covers bone surfaces at synovial joint
- supports the laynx, trachea, bronchi
elastic cartilage
provides support but tolerates distortion
- contains elastic fibers
where is elastic cartilage found
this is found at the external ear, the epiglottis, the auditory canal
fibrous cartilage
- contains dense collagen fibers that resist compression
- can sometimes lack pericardium
- prevents bone to bone contact
where can fibrous cartilage be found
-this is found in the pads of the knee joint, between pubic bones, intervertebral discs
describe what makes up bone tissue
- it is 35% organic components (collagen fibers, ground substance)
- it is 65% inorganic compounds like mineral salts that invade the bony matrix
- together it makes a strong yet flexible combination that is resistent to shattering
osteogenic cells
these are the stem cells that turn into osteoblasts
osteoblasts
these are the builders of the bone
osteoclasts
these break down the bone for remodeling or to harvest calcium
-these have multiple nuclei
osteocyte
this is a mature osteoblast
-these are responsible for the maintence and turnover of mineral content surrounding bones
compact bone
- covers the surface of all bones
- the thickness depends on the amount of stresses that occur there
osteon
- this is the functional unit of the compact bone
- it has osteocytes arranged in circular layers around the central canal
central canal of osteon
- this is where blood vessels are contained
- these run parallel to the surface of the bone
concentric lamellae
the cylindrical rings around the central canal
interstitial lamellae
- these fill in the spaces between the osteons
lacunae
small chambers that the osteocytes live in
circumferential lamellae
these occur at the external and interstitial surfaces of the bone
canaliculi
the channels that connect lacunae together with each other and to the central canal that allow nutrients to pass through
perforating canals
passageways within compact bone that extend perpendicular to the surface
-blood vessels in these deliver blood to the osteons deep in the bone and service the medullary cavity
marrow
this is a loose connective tissue within the medullary cavity
red marrow
a mixture of mature and immature RBC and WBC
- important sites of cell formation
- in some spongy bone of adults and medullary cavity in children
yellow marrow
dominated by adipocytes
- this is an important energy reserve
- this is in the diaphysis in the medullary cavity
appositional growth
- increases the diameter of cartilage and bone
- this happens within bone throughout life (not cartilage)
trabeculae
layers of parallel lamellae and osteocytes
-these are in spongy bone
periosterm
fibrous outter layer and inner cellular layer that surrounds all bones (except joints) that aids in the attachments of surrounding tissues/ligaments/tendons
-the inner cellular layer is important for bone growth
bony prominance
something that sticks out of the bone for attachment purposes
-attachment causes pulling on the bone so it grows in that direction
articular surface
where they make a joint with another bone
depressions
these are where things are traveling along a bone ( maybe a nerve or a blood vessel)
functions of bones:
- support
- movement
- protection
- mineral storage
- hematopoisis
- energy metabolism
spongy bone
arranged in paralle thick branching plates called trabeculae
- there are lots of holes in these spaces
- make the overall weight of the skeleton lighter
- resists stresses from multiple directions
endosteum
-an incomplete cellular lining found on the inner surfaces of the bone that lines the medullary cavity
what are the four major blood supply to bones
- nutrient artery and vein
- metaphyseal arteries and veins
- epiphyseal arteries and viens
- periosteal arteries and veins
ossification
also known as osteogenesis
-bone formation
intramembranous ossification
bones formed directly from a membrane of connective tissue
-this is the formation of flat bones
flat bones
skull, mandible, some facial bones scapula, clavicle
endochondral ossification
- develop from hyaline cartilage
- this is what the rest of the bones in the body develop from
- this begins in the 8-12th week of embryonic development and continues froming into early development
steps of intramembranous ossification
- the stem cells of the mesenchyme (embryonic tissue) differentiate into osteoblasts and secrete matrix (turns into ossification centers)
- formation of bony spicules (they are reaching out from the ossification sites and they are pulling them together, forming larger ossification sites)
- entrapment of blood vessels (important for nutrients being provided to the cells
- formation of spongy bone
mesenchyme
a tissue or clustering of cells that is originating from the embryonic development
endochondral ossification
- cartilage in the middle begins to calcify and die
- the stem cells on the outside turn into osteoblasts and build a bony collar in response to the cartilage death in center
- creation of the primary ossification center when blood vessels enter the middle of the hyaline and bring osteoblasts and osteoclasts with it
- formation of the medullary cavity
- we begin to see the formation of secondary ossification centers in the epiphyses
- growth plate has developed and interstitial growth occurs
- growth plate closes and the bone is no longer growing
interstitial growth
- this occurs in cartilage only
- this increases length
- chondrocytes divide and push each other apart, secrete matrix and move further from the origin
- they are each synthesizing and secreting new cartilage
- the cells become large and calcify and die off
- osteoclasts will come up and clean up the dead areas and the osteoblasts will come in, secrete matrix, lay down bone and replace what once was cartilage
where does interstitial occur
- this occurs at the epiphyseal plate
what is important to remember about development of cartilaginous growth
- most cartilaginous growth (everything but at the epiphyseal plate) occurs in embryonic developments and happens before we enter the world
steps of appositional cartilage growth
- growth occurs along the periphery
1. stem cells at the edge of the perichondrium divide
2. results in new stem cells and chondroblasts positioned at the periphery of the original cartilage
3. chondroblasts lay down matrix, separate, and become chondrocytes within lacunae
appositional bone growth
- growth occurs along the periphery
1. osteoblasts lay bony matrix on the periphery, creating ridges
2. ridges eventually meet and encapsulate a blood vessel
3. bone deposition proceeds inward creating an osteon
4. additional circumferential lamellae are deposited, increasing the bone diameter
what are the functions of bone remodeling
- maintain calcium and phosphate levels
- responds to stress that is placed on it
- this is constantly occuring and and we are in a constant state of laying down new bone and resorbing old bone*
how does bone formation and bone resorption change throughout life
- there is greater formation in children
- balanced formation and resorbtion in young adulthood
- greater resorption in older adults
what does stress do to bone
- it can cause it to remodel
- bones are designed to be able to withstand stresses based on how they are anatomically designed
- the compression and tension placed on bones are able to be shifted throughout and the use of spongy bone to withstand stresses and loads in multiple directions and redirect it toward other parts of the bone is important
what are the effects of exercise for the skeleton
- mechanical stress stimulates increase in bone density by increasing osteoblast activity
- bones of athletes become thicker and stronger because of this
- bones lose mass with age but this can be slowed or reversed with weight bearing exercise
what do vitamines A and C do
these stimulate osteoblast activity
what does vitamin D3 do
this promotes calcium and phosphate absorption into blood and assists with calcification
rickets
this is a vitamin d deficiency as a child and can cause legs to bow out and bones are more flexible
osteomalacia
this is a vitamin d deficiency in an adult
osteooarthritis
aging and stress result in decreased chondrocyte ability to maintain and repair the matrix
-ex. breaking down of the articular cartilage in the synovial joint
osteopenia
bone mineral density is lower than normal
osteroporosis
rate of bone breakdown and reabsorption by osteoclasts is greater than production of osteoblasts causes weak and brittle bones with many holes in them
axial skeleton
- skull
- spinal column
- ribs
appendicular skeleton
- upper and lower limbs
- pectoral girdle
- pelvic girdle
articulations
- joints
- where bone meets another bone, cartilage, or teeth
- these vary in stability and mobility
- the more mobile something is, the less stable it is.
what factors influence joint stability
-articular surfaces
(shape influences movements and possible stability)
-ligaments
(capsules and ligaments prevent excessive motions)
-muscle tone
(stabilizes joint by keeping pressure on tendons)
immobile joints
- two types
- fibrous and cartilaginous
- these are extremely stable and things we do not want moving
ex. teeth or the epiphyseal plate
synovial joints
- articulating bones separated by a fluid filled joint
basic components of a synovial joint
- articular capsule
- articular cartilage
- joint cavity
- synovial fluid
- ligaments
- nerves and blood vessels
articular cartilage
- covers the bony surfaces within the synovial joint to absorb shock and reduct friction
- hyaline cartilage
articular capsule
- two layers
1. fibrous outer layer
2. inner synovial membrane
fibrous layer of articular capsule
- made of dense connective tissue
- this creates stability
synovial membrane
- secretes the synovial fluid (and some macrophages)
bursae
this is an accessory structure in the synovial joint
- a sac containing synovial fluid
- reduces friction as the joint moves in space
tendon sheaths
this is an accessory structure in the synovial joint
- elongated bursae around tendons
- reduces friction of the tendon
fat pads
this is an accessory structure in the synovial joint
- packing material and provides some protection
- used to fill space
coronal plane
divides the body front and back
-movement through this plane occurs at the anteroposterior axis
sagittal plane
- this divides the body left and right
- movement through this plane occurs at the transverse axis
transverse plane
- this divides the body up and down
- movement through this plane occurs at the vertical axis
give an example of a movement through the coronal plane
- this would be about the anteroposterior axis
- doing jumping jacks, the arms and legs move about that axis
give an example of a movement through the sagittal plane
- this would be about the transverse axis
- this would be moving the head up and down to say yes
give an example of a movement through the transverse plane
this would be about the vertical axis
-moving your head left and right to say no
eversion
is a motion of the ankle that turns the sole outward
inversion
this is the opposite of eversion and it is the motion of the ankle, turning the sole inward
dorsiflexion
upward movement of the foot through the flexion of the ankle
plantar flexion
downward movement of the foot through the extension of the ankle
lateral flexion
-this occurs when the vertebral column bends to the side
protraction
moving a body part anteriorly in the horizontal plane
-you protract your jaw when you grasp your upper lip with your teeth
retraction
moving a body part posteriorly in the horizontal plane
-you retract your jaw when you move it back to normal after grasping your upper lip with your teeth
opposition
a special movement of the thumb that produces pad to pad contact with the palm or any finger
reposition
movement of the thumb back into normal position after it was having pad to pad contact with a finger or palm.
elevation
movement in a superior, upward motion
-you elevate your mandible when you close your mouth
depression
movement in an inferior, downward motion
-opening your mouth depresses the mandible
gliding motion
two things moving past each other
flexion
a movement in the anterior posterior plane that decreases the angle between the bones of the joint
extension
a movement in the anterior posterior plane that increase the angle between the bones of the joint
abduction
away from the midline
-spreading fingers apart
adduction
moving toward the midline
-bringing fingers together after they were spread
circumduction
- a movement of the synoival joint in which the distal end of the joint moves in a circular motion but the shaft of the bone does not rotate.
ex. moving the arm in a circle, as when drawing a large circle on a chalkboard in one continuous motion
what are the four types of synovial joints
- nonaxial
- uniaxial
- biaxial
- multiaxial
nutrient artery
- enters the bone through the nutrient foramen, runs obliquely through the cortex, sends branches upward and downward to the bone marrow,
epiphyseal arteries
-these supply the osseous tissue by entering numerous small foramina of the epiphyseal of long bones
medullary cavity
the central cavity of bone shafts where red bone marrow and/or yellow bone marrow is stored
woven bone
- (also known as fibrous bone) is characterized by a haphazard organization of collagen fibers and is mechanically weak
- this is made in intramembranous ossification
lamellar bone
- has a regular parallel alignment of collagen into sheets (“lamellae”) and is mechanically strong.
- this is made in intramembranous ossification
Periosteal bone collar
appears during endochondral bone development to support the growing bone and help it retain its shape.
sprain
tearing of a ligament
hinge joint
this permits angular motion in a single plane
ex. elbow joint, knee joint, ankle joint
- uniaxial
plane joint
- gliding joints
- these have flattened or slightly curved surfaces that slide across one another
- nonaxial
ex. vertebrocosal joints
pivot joint
these permit rotation only
- uniaxial
- an example would be the movement of the atlas on the dens of the axis vertebra
saddle joint
- complex articular faces that fit together like a rider in a saddle
- biaxial
- ex. thumb joints
condylar joint
- these have an oval articular face nestled into the depression on the opposing surface
- biaxial
ex. joints in the 2-5th finger joints
ball and socket joint
- a round head of one joint fits in a cup shaped depression in another joint
- multiaxial
ex. shoulder joint, hip joint
uniaxial
this is a rotational movement
biaxial
this has two motions
multiaxial
this has a lot of motions and movement
