two main parts of the skeleton
axial and appendicular
what is the axial part of the skelton
runs down the middle
3 parts of the axial skeleton
skull, vertebral column, thorax
3 parts of the appendicular skelteon
limbs, pelvic griddle, shoulder griddle
wha is the appendicular part of the skeleton
branches off the middle
what are the two main types of bones
compact bones and spongy bone
what is compact bone
makes up the outside of most bones
what is the compact bone filled with
solidly filled with matrix
which of the two bone types is the most common
compact bone
what is spongy bone
makes up the inside of most bones
has many holes inside
where is spongy bone found
in the marrow area of bones
what are the 5 shapes of bone
long, shorts, flat, sesamoid, irregular
what are long bones
“standard” idea of a bone that are longer than they are thick
standard bones are the most important part of what
skeletal movement
what are the three parts of long bones
epiphysis, metaphysis, diaphysis
what is the epiphysis
head, had red marrow
what is the metaphysis
“growth plate”
what is the diaphysis
shaft, has white marrow
what else are long bones important for
support
how do long bones grow longer
metaphysis: in young bones it is made of cartilage and creates new bone on diaphyseal side and cartilage on epiphyseal side.
what is the epiphyseal plate
the growth plate
what happens once the bone has stopped growing
it ossifies and turns into an epiphyseal line
what is ossifying
cartilage turns to bone
what are the long bones in your arm
the radius: forearm lateral in anatomical position
the ulna: forearm, medial in anatomical position
the humerus: upper arm bone
what are the long bones in your leg
femur: thigh area, longest and strongest bone in the body
tibia: “shinbone”, bears most weight of any bone
fibula: lateral to tibia, dosen’t bear weight
what are the long bones in your hand
metacarpals, phalanges
how many phalanges in the body
56
what are metacarpals
longer bones that connect to wrist, 5 of them in hand
what are phalanges
shorter bones, 3 on each finger except on thumb (pollex) , which has 2
hand numbering
pinky finger= 5
thumb = 1
furthest phalanx
distal
closest phalanx
proximal
what are the long bones of the foot
the metatarsals and phalanges
what are metatarsals
longer bones that connect to the ankle, there are 5 of them
what are the phalanges (foot)
shorter bones-3 on each toe except on big toe (hallux) which has 2
foot numbering
pinky toe= 5, big toe = 1
(foot) what is the furthest phalanx
distal
(foot) closest phalanx
proximal
what is the clavicle
the collarbone an the most commonly broken bone
what is the first bone to begin ossification
the clavicle
last bone to finish ossification
clavicle
what are short bones
as wide as they are lomg
what do short bones do
provide structure and support but little movement
wrist/hand bones?
8 carpals
foot/ankle bones
7 tarsals
what are flat bones
bones that are flat in shape they are predominantly for protection
what are the 3 bones of the pelvis
ilium, ischium, pubis
what is another flat bone example
skull, ribs and sternum, pelvis, scapula
how are ribs numbered
from top to bottom
how are ribs attached to the sternum
costal cartilage
how many ribs are true
1-7
how many ribs are false
8-12 rbs
what are false ribs
connect to rib #7
what are floating ribs
ribs that do not connect to the sternum at
which ribs are floating ribs
1 and 12
what is the xiphoid process
flat projection at the base of sternum
what is the scapula
the shoulder base
what are sesamoid bones
flattish bones embedded in a tendon or muscle
the most basic example of sesamoid bones
the kneecap (patella)
how do sesamoid bones generally grow
in response to stress or strain in a tendon
where are sesamoid bones often found
in toes
do sesamoid bones vary by person
yes
what are irregular bones
bones with shapes that don’t fall into another category
examples of irregular bone
vertebrae in back
many lower facial bones
hypoid bone in neck that connects tongue
how many vertebrae make up your spine
33
what are the 5 different kinds of vertebrae
cervical thoracic lumbar sacral coccyx
cervical
7 of them
thoracic
12 of them, each articulates with a rib
lumbar
5 of them
sacral
5 of them fused together
coccyx
4 of them fused together
each vertebra has a similar body
- body
- canal
- processes
body of vertebra
bears weight
canal of vertebra
allows spinal cord to pass
processes of vertebra
allow muscle attachment
how does the spine generally run
straight dow n the midline and has a slight S shape
what are the 3 common deformities
scoliosis
kyphosis
lordosis
what is scoliosis
side-to-side sway
what is kyphosis
forward bend of T and S regions
what is lordosis
backward bend of L and C regions
what are joints
where bones meet other bones
how may joints in the body
over 200
how are joints sorted
by how much they move
three things joints can be
synarthroses, amphiarthroses, diarthroses
what is singular synarthroses
synarthrosis
what are synarthroses
immovable joints,
what are amphiarthroses
aka slightly movable joints
example of synarthroses
plates of skull fuse together
example of amphiarthroses
connections between vertebrae in back
what are diarthroses
freely movable joints
diarthroses are filled with what in synovial joints
a liquid called synovial fluid
what does synovial fluid do
lubricate the joint
what is synovial fluid held in by
cartilage
what can synovial fluid become
infected like septic arthritis or filled with blood like hemorrhagic arthritis
what is cracking joints
popping of small air bubble that forms in synovial fluid when pressure quickly changes
what is cracking joints not linked to
arthritis or joint problems
what do plane joints allow
gliding or rotating motion
what are plane joints
two flat surfaces against each other
where are plane joints found
between carpals, tarsals
what do hinge joints allow
movement across one plane
howdo hinge joints work
cylinder rolls in U shape
6 shapes of Diarthrotic Joints
plane hinge pivot condyloid saddle ball and Socket
examples of hinge joints
elbow, knee, joints between phalanges
what do pivot joints alow
rotation around one plane
what is a pivot joint
a circle in a bigger circle
examples of pivot joint s
radius/ulna, top two vertebrae of neck
what do condyloid joints allow
front/back and side/ side movement
what are condyloid joints like
egg in sock
examples of condyloid joints
proximal phalanx/ metacarpal
what do saddle joints allow
allows front/back and side/side movement, but not easily both together
what do saddle joints look like
two saddles on each other
examples of saddle joints
trapeziometacarpal joint in thumb between first metacarpal and carpal, gives us opposable thumbs
what do ball and socket joints allow
motion in full circle, plus rotation
what do ball and socket joints look like
a ball in a socket
example of ball and socket joints
humerus in shoulder, femurs in hip
what are ligaments tendons and and fasciae made of
primarily collagen
what do ligaments do
connect bone to bone
what do tendons do
connects bone to muscle
what do fasciae do
connects muscle to muscle
what is a sprain
a damaged or torn ligament
what is a first degree sprain
some damage
what is a second degree sprain
partial tear
what is a third degree sprain
a full tear
what happens in third degree sprains
the joint runs high risk of dislocation
what is tendonitis
the acute (sudden) inflammation of a tendon
why does tendonitis happen
because of repeated motion , leading to slight tearing in the tendon, can also happen because of bone deformation that causes unnecessary abrasion against the tendon
what is tendonosis
tendonitis that lingers for years
where can tendonitis happen
all over the body because tendons are all around the body
what are the common affected by tendonitis
elbow, patellar tendon, achilles tendon, rotator cuff
tendons and ligaments are what tissue
dense connective tissue
how are the tissues of tendons and ligaments
lot of matrix composed of parallel collagen and elastin along with some cells called fibroblasts
what do fibroblasts do in tendons and ligaments
maintain the matrix
what does healthy tendon or ligament look like
much collagen and elastin in parallel lines/waves, few cells
what does damaged tendon/ligament look like
much collagen/elastin but not as taut, many more cells
what is the difference between a break, a crack, and a fracture
nothing, they all mean the same thing the bone’s integrity has been compromised
breaks can be what one of two things
closed fractures, or open fractures
what are closed fractures
do NOT pierce the skin
what are open fractures
do pierce the skin
what are the types of fractures
- stress fracture
- greenstick fracture
- compression fracture
- complete fracture
- comminuted fracture
what are the types of complete fractures
transverse
oblique
spiral
what are stress fractures also called
hairline fracture
what do stress fractures come from
NOT from one severe trauma, but extended overuses
here are stress fractures common
in athletes
which bones are stress fractures the most common
in wight0bearing bones like the tibia, femur, metatarsals
what are greenstick fracture
come from an incomplete fractures through the bones
how do bones break in greenstick fractures
like a “green stick” a piece splinters off, but part stays intact
where does greenstick fractures usually happen
in patients under 10 years old, because more cartilage and less ossification
what is a compression fracture
part of bone is crushed or caved in
where do compression fractures almost always happen
in a vertebra
what are compression fractures caused y
osteoporosis, bones cannot support normal amount of weight because they have low mineral density
where are compression fractures seen almost exclusively
geriatric patients
what is geriatric patients
old people
what is a complete fracture
bone breaks all the way through
what is a transverse complete fracture
perpendicular angle
what is oblique complete fracture
non perpendicular angle
what is a spiral complete fracture
break a rotating angles
what is a comminuted fracture
bone break into many fragments
what are comminuted fractures often from
high-speed or high-trauma events
what do comminuted fractures often require
screws or plates to hold bone together
how does the body heal fractures
- Hematoma forms
- Fibrocartilage callus forms
- Bony callus forms
- Bone remodels to a permanent patch
the bone will heal regardless of what
whether it is set in place
what happens if a bone isn’t set in place when healing
it will heal crooked and your bone will be forever curved
when does hematoma forms
6-8 hours after the bone break
how do hematoma form
when a bone breaks, blood vessels surrounding and inside it also break. this will lead to swelling in the area called a hematoma
what happens to many bone cells near the break
deprived of their normal blood flow and die
what is a hematoma
blood mass
when do fibrocartilage callus forms
around 48 hours after the break
what happens when firbrocartilage callus forms
fibroblasts and osteoblasts migrate to damaged site, make fibrocartilage
what is fibrocartilage
cartilage matrix+ bone matrix+ collagen
what happens to capillaries when fibrocartilage callus forms
capillaries begin redeveloping
what happens to phagocytes when fibrocartilage callus forms
remove some debris
what are phagocytes
a type of white blood cell
when does bony callus forms
after 3-4 weeks
what happens when bony callus forms
the fibrocartilage slowly starts to ossify as more and more osteoblasts arrive at the fracture site
what is the break full of when bony callus forms
new immature spongy bone
when does bone remodel to a permanent patch
after 8-10 weeks
what happens when bone remodels to a permanent patch
- compact bone settles around the edges
- dead cells are removed by osteoclasts
- bone eventually reaches full strength again (usually)
bones are constantly what
broken down and rebuilt
what do osteoblasts do in bone remodeling
build bone (ossification)
what do osteoclasts do in bone remodeling
break bone apart (bone resorption)
how much of skeleton is replaced each year
about 10%
what is wolf’s law
bones remodel according to the stress placed on them, more stress= stronger bone
what is a trabeculae
( “lines” of spongy bone), remodel to run parallel or perpendicular to stress
if you don’t use a bone it
gets weaker
what happens after age 30
more bone resorption than ossification
what is the result of more bone resorption than ossification
bones slowly get less dense and weaker (osteoporosis)
who is osteoporosis most common in
postmenopausal women
what is RANK Ligand
bind and activates RANK receptors on osteoclast membranes and increases osteoclast activity
what is a ligand
something that sticks to a receptor
what does estrogen do
- down regulates RANK ligand production, leads to less osteoclast activity, less resorption
- estrogen upregulates osteoprotegerin (OPG) production. OPG binds to RANK ligand and blocks it from binding to RANK receptors which leads to less osteoclasts activity and less resorption
what do RANK receptors do
leads to less osteoclasts activity, less resorption
what happens in menopause
estrogen production dramatically decreases, osteoclast activity and bone resorption increases
5 main functions of bone
support protection movement storage blood cell formation
bone serves as what
a series of supports to hold the body together
what does the skeleton do
provides support for vital organ
what are the important organs
brain, heart, spinal cord
pelvis does what
holds in organs
what do legs act as
pillars to support weight
what protects the brain
the skull
what protects the heart
rib cage
what protects the spinal cord
the spine
what else do bones serve as
levers pulled by muscles
each muscle has one or more sites where it
attaches to bones/tendons
bone matrix is made of a mix of
collagen fibers and hydroxyapatite
over 99% of the body’s calcium is found where
the bones
what is the formula for hydroxyapatite
Ca10(PO4)6(OH)2)
what are the main elements in bone matrix
calcium and phosphorus
calcium ions must be found where in small amounts to what
the blood to maintain charges in cells
how does the thyroid detect blood calcium levels
chief cells in the parathyroid and C cells in the thyroid each have receptors to detect serum ( blood) calcium levels
what is the normal serum calcium levels
9-10 mg/dL
when do you know when calcium blood levels are normal
neither cell type does anything
what is it called when there is not enough calcium in the blood
hypocalcemia
what happens to combat hypocalcemia
chief cell’s receptors detect this and trigger production of a hormone called parathyroids hormone (PTH)
what is it called when there is too much calcium
hypercalcemia
what happens to combat hypercalcemia
C cell’s receptors detect this and trigger production and release of a hormone called calcitonin
regulating blood calcium levels are
negative feedback loops
what are the functions of PTH
- leads to the stimulation of osteoclast activity
- it leads to the inhibition of osteoblast activity
- it tells your kidneys to filter out less calcium from the blood
- it tells your kidneys to produce more of an enzyme which turns calcidiol in to calcitriol (Vitamin D)
what are osteoclasts
bone cells that break down bone matrix which releases calcium into the blood
what are osteoblasts
bone cells that build up bone matrix
what does Vitamin D do
causes your small intestine to absorb more calcium than normal
what does calcitonin do
- inhibits the activity of osteoclasts
- tells your kidneys to filter more calcium from the blood
osteoblasts do not have receptors that can detect what
calcitonin, so it has no effect on them
what is Miacalcin
a prescription drug that causes salmon calcitonin to delay osteoporosis
what is the production of blood
hematopoiesis
where is red marrow found
in the head of long bone
what is the function of red marrow
produces mostly erythrocytes (red blood cells)
where is white marrow found
in the shaft of long bone
what does white marrow do
produces mostly leukocytes (white blood cells )
all blood cells come from what
a cell line called hematopoietic stem cells, which are pluripotent stem cells, these cells live in bone marrow
the carpals
Hamate
Pisiform
Triquetral
Lunate
Trapezoid
Trapezium
Scaphoid
Capitate
the tarsals
Calcaneus Talus Navicular Cuboid Cuneiforms
thumb
pollex
big toe
hallux