hello and welcome to this exam question video today we're looking at question 16.1 and 0.2
which are asking you about different types of joints in the body now for
aqa gcse you only need to know these two joints we've got hinge
and the ball and socket now what i will quickly do is run you through other ones that you will
need to know as you progress onto b103 or a level or ib whatever it might be
or if you are watching this from a more macro look at things not just aqa gcse you will need to know
different types of joint as well so the two that we're going to look at are the hinge and the ball
and socket or b and s but within that or sorry outside of that i should say which you don't
know if your aqa exam but are also present around the body we've got the saddle joints
we've got the plane or the gliding joints if i just put plane down we've got pivot joints
and condyloid i'll quickly run through these ones in red and then we will focus on the ones
which i've just highlighted in green there that we actually need for this exam question
so the saddle looks a little bit like a horse saddle where or pringles is another way to think
of it if you were to stack two or two pringles one on top of the other and you'd be able to slip that
pringle on the top either up and down or rotate it across like that so it's when the two bones which
are meeting have those shapes such as in the thumb you can slip them up and down or over and under
plain joints or gliding joints are when two bone surfaces are flat on top and they can
move across each other like so pivot is where we have a protrusion on one bone and then a ring
or a hoop or a gap which slots over the top and then can rotate on the top so that thumb circle
and then pivots around it the condyloid joint is then similar to the board and socket it's just a
little bit shallower it hasn't got as much range of movement as we do when we have a full ball in
a full socket where we've got multi-directional movement a condyloid is almost a shallower disc
shape and a more gradual curved end which slots into it so we still get that multi-directional
movement but just a little less which brings us onto the two that we are caring about for
this exam question here so give an example in the skeleton of a hinge joint which just like a door
can open and close a hinge joint only allows movement in two directions forwards and
backwards or flexion and extension and in the body we're dealing here with our knee our elbow and
our ankle now the ankle is a it's a complex joint which for gcc level you just need to know
it as a hinge joint which can perform plantar flexion when toes point down towards the floor
where you plant your foot into the floor for plantar flexion and dorsiflexion which is you lift
your toes up to the sky contracting your tibialis anterior and by doing that you could be stopping
the door so dorsiflexion just stop the door plantar flexion to plant your foot into the ground
now at the ankle we also have e-version of inversion but there's technically two joints
at the ankle but for gtfc level you just need to know about the top joint or the true joint
which is a hinge joint which that allows for that plantar flexion and dorsiflexion so that would be
one example the knee and the elbow obviously we have flexion and extension occurring there
without you know multidirectional movement being possible if we were to cause multi-directional
movement such as going sideways into abduction or adduction or rotation for example then
it's possible that the joint could dislocate and cause injury and damage to that joint
below we've got an example for example in the skeleton where a ball and socket joint can be
found so like i said and demonstrated earlier a ball and socket joint is the bone with a round
head which slots into a recess or a cup or a bowl or a socket so as they connect that head of that
bone can rotate in most if not all directions with a wide range of movement and it can achieve the
widest range of movement actions out of all of the joints so where do we find these these types of
joints in the skeleton at the shoulder and at the hip so the shoulder huge range of motion in every
single direction the hip it's a little bit more restricted just because of the joint structures
and the ligaments and the muscle structures around that as well but where in the body do we find the
ball and socket joint the shoulder and the hip so that's a quick run through of the joints that
do exist but for aqa gtsc you just need the hinge and the ball and socket where are they in the body
the hinge is in the elbow the knee the ankle where are the sockets they're in the shoulder
and the hip so i hope you found that useful i'll see you again in the next video bye for now