hello all this is dr alsup and in this video this is going to be the first in the series regarding
the basics of joints gotta love those joints and i always like to start a new area discussing the
big picture functions of that system so that's exactly what we're going to do here talk functions
but you really can't talk function until you understand what a joint actually is so first
things first and then we will get into the two main functions of joints so simply put a joint
is a point of contact between two bones or a bone and cartilage or even a bone in a tooth
and you will often hear joints also referred to as articulation or not and articulation and
actually i myself am quite partial to the term articulation you will definitely hear me say that
occasionally you'll also hear the term arthrosis in order uh as a as another term for
a joint so when you hear the phrase these bones articulate which will definitely hear from me
think these bones form a joint now here is one of the most important concepts of this whole session
so put all your stars and smiley faces next to it and that is that bones actually do not contact
one another directly alright so bones do not contact each other directly in fact having direct
bone on bone contact is pathological so indicating some type of disorder is occurring in that region
something like osteoarthritis can lead to bone on bone contact when the articular cartilage is gone
there is always some other connective tissue like cartilage that is always present between the bones
so it is that connective tissue that will actually contact in certain situations
so the functions of joints well the main one is that joints play a role in either allowing or
limiting or completely not allowing movement to occur so we will learn that some joints
allow absolutely no movement whereas some like the shoulder joint allows a free range of movement
and i think this function is pretty intuitive and generally what we think about when joints
pop in your mind so you may think "my fill-in-the-blank joint hurts" like your my knee joint hurts
and now i can't move the way i typically can so that's something that is not an uncommon
thought process when we're thinking about joints so we will work through the
concepts of movement and joints in many different ways in many upcoming videos
now probably less intuitive with when thinking about joints is that certain joints can actually
facilitate growth in particular synchondrosis that involve epiphyseal plates which are located
in certain areas or in certain metaphyses of growing bones
so these are actually examples of joints and if you think about it it makes sense you have
you have two bony parts that are meeting up together by and you'll have this kind of
intermediate portion of connective tissue in this case we're talking hyaline cartilage
so if you've forgotten what an epiphyseal plate is make sure to review the bone formation video
or part to the long bone video and we will also review the term synchondrosis
in upcoming joint videos when we're discussing the types of cartilaginous joints
okay so that is your first intro into joints and i think we are off to an amazing start but before
you move on to the next video i want you to mull over some of these more conceptual questions so
even if you have very little background in musculoskeletal anatomy and specifically
joint anatomy just in very general terms i want you to think of some joints or some areas where
bones meet that would allow absolutely no movement or you know maybe just a little bit of movement
or conversely i want you to think of joints that would allow the most movement or a lot of movement
so in addressing this first question this little to to no movement i want you to try them
try to move the bones of your skull but not including your lower jaw or mandible
so try to do that right now you just can't right if your head moved when you tried to
do that it was because of your vertebral joints not the joints between the bones of the cranium
which are immovable in adults so these are pretty classic examples of immovable joints
you may have come up with some other ones and i assure you we'll talk about
all of them as we kind of move through the course now i want you to try to move your shoulder joint
or your hip joint and these are comparatively moving all over the place particularly in
comparison to the the sutures of the the cranium now try to move your elbow joint
yeah you got some affliction and extension there that's not quite as much a range of movement or
motion as you had with the shoulder and hip but certainly more so than you had with the sutures of
the skull okay so these questions were just here to get you thinking about things that you already
kind of knew but perhaps we're putting these into different contexts and using some terminology that
you're not quite familiar with but you will as we move through the course in our next video we will
begin to explore the joys of joint classification schemes always one of my all-time favorites
thank you for your time and attention here and always feel free to reach out with any questions