Chapter 7: Skeletal System / Joints Flashcards
what are the different kinds of bone shapes?
long, short, flat, irregular, sesamoid
development vs growth?
development is starting with something, and growth is making something it already had
ossification vs calcification
ossification deals with bone, calcification accumulates calcium
what is irregular bone mostly made of?
spongy bone
What happens when spongy bone fails?
The vertebrae form a pie shape, which causes a hunchback
What is a sesamoid surrounded by ?
Soft tissue
Where is the periosteum found
Around the outside of the organ
What is the periosteum
Dense fibers holding it to the bone
What is the proximal and distal epiphysis covered in
Articular cartilage
Where is the diaphysis?
Middle section of the long bone
What is the purpose of having spongy bone on the ends of a long bone
Has a larger surface , but since it’s porous it’s light
What is the endosteum
A membrane that lines the medullary cavity
What is the medullary cavity
A hollow structure filled with blood vessels
What does yellow marrow mainly consist of
Fat
what is a lamellae
is a ring of bone tissue
what is an osteon
a bunch of concentric rings
which type of bone has tons of blood vessels?
compact bone
what is a canaliculus
passage ways through the matrix
what is a lacuna
where the osteocytes are found
what is trabeculae
boney plates
which kind if bone is most likely to fail if it has osteoporosis?
spongy bone
what is hyaline cartilage
the starting material for bone development
what is found in the extracellular matrix
fibers
what does the nuclei of fibroblasts do?
makes fibers (collagen)
where does intramembranous ossification take place
flat bones
what is a progenitor cell
known as a stem cell, it is a developing cell into some kind of connective tissue. you only have these cells as a fetus
what is the ossification center
where it all started
what is an osteoblast
they activated the right genes to start the pathway to bone cells, by producing their own lacuna around themselves with the canaliculi passageway it is able to make bone
how is an osteocyte created
when it builds lacuna
which kind of bone shows up last in intramembranous ossification
compact bone; it only goes where you need it
what kind of bone is always created first in both intramembranous ossification and endochondral ossification?
spongy bone
what does endochondral ossification start as?
hyaline cartilage
what is the epiphyseal plate
part of the bone that grows in length
what does secondary ossification center mean
just that it shows up later, it is not less important
what is the zone of resting cartilage
it attaches to the epithelial plate and is not actively dividing. it has a very slow metabolic rate
what is the zone of proliferating cartilage
it is in active cell division
what is zone of hypertrophic cartilage
has a high level of growth
what is the zone of calcified cartilage
dying cells
what is the relative term for diaphysis
proximal
osteocyte ?
found in lacuna
osteoblast?
makes bone tissue
osteoclast?
destroys bone tissue
purpose of vitamin D?
absorbs calcium
why are vitamins important for bones
critical for bone maintenance
what does calcitonin do
lowers calcium
why is the purpose of a thyroid gland
monitors the calcium intake
what is calcitonin
it stimulates osteoblasts which takes calcium out the blood and into bones
where is the parathyroid gland located
behind the thyroid
what does the parathyroid hormone do
it stimulates osteoclasts which break down bone tissue
what does parathyroid mean
to raise calcium
definition of synarthrotic
no movement
defintion of amphiarthrotic
slight movement
definition of diarthrotic
movement, wide range of motion
synovial joints
fluid space between bones
cartilaginous joints
only cartilage is between the joints
fibrous joints
fibers and connective tissue; bones are held together by collagen fibers
what type of joint is a suture?
synarthrotic, which means there is no movement
what is synchondrosis held together by?
hyaline cartilage
where is fibrocartilage found?
disc of the pubic symphysis ; it has slight movement
synovial joint
diarthrotic; has a wide range of motion
where does articular cartilage come from?
comes from the hyaline cartilage when we were a fetus
whats the purpose of synovial fluid
reduces friction
whats the purpose of a joint capsule
keeps the synovial fluid in
bursa
limits friction within the tendons; it is found in joints with a wide range of motion
menisci
reduces pressure, made of dense connective tissue; only found in the knee and jaw
sutures are?
not capable of movement; synarthrotic
invertebral joints are?
amphiarthrotic ; slight movement
the elbow joint is ?
biaxial
which joint is the most mobile joint?
shoulder joint
by definition what are all synovial joints ?
diarthrotic
which plane of movement is flexion and extension?
multiaxial
which plane of movement is adduction and abduction?
multiaxial
which plane of movement is rotation?
multiaxial
what is a saddle joint
two joint movement
facilitated diffusion
a type of diffusion in which the molecules move from the region of higher concentration to the region of lower concentration assisted by a carrier
which ion is greater in the extracellular fluid
sodium
which ion is greater in the cytoplasm
potassium
what is compartmentalization
like cabinets in a kitchen; the cell membrane creates compartments
what is passive ion movement?
ions near the membrane will be the only ones to go through because of diffusion
what is the resting potential membrane?
when a cell isn’t sending an impulse
why is the potassium permeability greater than the sodium permeability?
because sodium comes in all the time with glucose, that is why there is a pump to move the ions out of the cell
what is a leak channel
its where things escape (always open)
what is the resting Vm?
-70
what is net flux
no net gains or losses, its at a steady state
what are dendrites
they carry the information toward the cell body
what is the trigger zone
the trigger zone is between the cell body and the axon. it is the point where the threshold is met; a change occurs
what is the cell membrane made of
fat
what’s the purpose of the Schwan cell
makes myelin
what is myelin
layers of the cell membrane that insulates the axon, which then makes the axon transmit nerve messages faster
what is synapse
when one nerve talks to another
what’s the synaptic knob
its a knob like structure that releases chemicals
what’s the presynaptic cell
brings the message
what is a graded response
if you have a tiny stimulus, then you’ll have a tiny response. big stimulus, big response
what occurs in a postsynaptic cell
the presynaptic neuron releases a chemical, chemical then acts like a ligand, ligand channels open, and sodium enters with its gradient which is what causes the positive charge
can presynaptic knobs send the same response ? or can they be different?
they can be different
what is depolarization
amount of polarization is smaller than the resting membrane potential (toward threshold)
what is repolarization?
goes back to where you started ( returns back to the resting membrane)
what is hyperpolarization?
larger than it was before (away from threshold)
what happens during repolarization?
ion channels close, and the active transport puts everything back to where it started
what is active transport
the process of moving molecules across a cellular membrane through the use of cellular energy
what does EPSP stand for
excitatory post synaptic potential
what does IPSP stand for
inhibitory post synaptic potential
what is EPSP
toward the threshold
what is IPSP
away from the threshold
what is temporal summation
closer together in time to meet the threshold
what is spatial summation
adding responses together to meet threshold
what is EPSP-IPSP cancellation
canceling out of messages so therefore nothing happens. 2 depolarizing stimuli and 2 hyperpolarizing stimuli; makes 0
what is subthreshold
all or none. all responses are identical once the threshold is met. doesn’t matter if you exceed threshold or barely reach it, you either get threshold or not
