In this lecture, the first on the series about
the upper limb, we are going to look at the
surface anatomy and osteology of the entire
upper limb. So we are going to look at the
surface anatomy of the shoulder, the arm, the
forearm and the hand, all of these regions
making up the upper limb. And then we are going
to move onto the osteology, we'll look at the
clavicle, the scapula, the humerus, ulna,
radius, the carpal bones, the metacarpals
and the phalanges and in each of these bony
structures, we'll look at specific landmarks
and these are important for muscle attachments.
We'll then finish by looking at various movements
that are performed by the upper limb which is a
complex part of the appendicular skeleton
enabling a great range of movements. So if we
just look at the general arrangement
of the upper limb, then on this slide we can
see we have a nice body plan of both the male
here and the female. And on the male, we can
see indicate here we have got the upper
limb, specifically we have got the arm region
here which is connected to the trunk by way
of the shoulder which we will talk more about here
and then connecting the arm to the forearm
we have the elbow joints which we can see
here and then most distally furthest away
from the main core of the body we find we
have the hand. The hand member connected to
the forearm via the wrist joint. On this
picture here, we can see an anterior
view of the upper limb, we can see more features
more surface features. We can see we have
this shoulder region and we can see a region
known as the axilla. This is your armpit.
And we can see we have the deltoid. This muscular
region that covers the shoulder joint and
we'll look at the deltoid muscle in quite some
detail as that covers the shoulder joint.
We then pass down distally towards the elbow
and between the elbow and the shoulder we
find we have the arm. We can see a groove
here that is separating biceps brachii and
triceps brachii here and this we can see the nice
cleft this way you can palpate the
brachial artery. So there are some important
surface landmarks here.
We can then move on to the elbow joint and we
have a prominent bulge on the medial aspect
of the elbow joint. This is known as the medial
epicondyle and that is important because the
ulnar nerve runs alongside this structure
and we will cover these details throughout
this lecture series. We then pass distally
from the elbow joint and we see the forearm,
we can see the anterior region of the forearm.
We have a prominent bulge on the lateral surface
of the forearm and this is due to a really
important muscle known as brachioradialis.
So we can see a bulge here caused by brachioradialis.
We can then move distally again and we can
see the hand. The hand is connected to the
forearm via the wrist joint where the carpal
bones connect to the radius and the ulnar
to form this wrist joint. And we can see we have
the palm of the hand, and then we can see we
have the thumb, the index finger, the middle,
the ring and the little finger that make up the
digits of the hand. So these some key surface
landmarks we can see on the anterior aspect
of the upper limb.
If we look at the posterior aspect, then again
we can see we have this muscular region here
caused by the mass of deltoid muscle. And
then we can see the posterior region, we can
see some impressions for the various heads
of triceps muscle. Again we can see the medial
epicondyle, this time from the posterior view
just as we saw it on the anterior view here.
We can see the olecranon, this bony prominence
on the posterior surface of the elbow.
Once again if we move into the forearm we
can see we have this posterior aspect here
and again on the lateral aspect, running along
the same aspect as the thumb this lateral aspect
here. We can see we have brachioradialis. If
we pass to the hand once again we can see
the thumb, index, middle, ring and little
fingers again that make up the digits and
we can see this dorsum of the hand. Remember
that forearm is connected to the hand via
the wrist joint and we have two what are known
as styloid processes of the radius and the
ulna. And we'll look at this in detail when we look
at the osteology. But both these styloid
processes of the radius and the ulna, the radius
being lateral, the ulna being medial.
Then we can see these bony prominences and
these can be palpated at the wrist joint.
So this region that we can see here on the
slide is the part of the superior appendicular
skeleton and it forms the upper limb. The
upper limb is important because it has a high
level of mobility. A high level of mobility
which is given to it via the pectoral girdle
which we will see in a few slides time. It
is also characterized by its ability to grasp
structures. The hand is a really important
structure at the distal end of the upper limb
and its ability to manipulate the fingers,
to hold or to grasp structures. So when
you are holding a pencil to write, it
is a complex arrangement of movements that
allows your fingers to assume this position.
It is the key difference from the lower limb.
The lower limb doesn't have this much mobility
as the upper limb and also it doesn't have
this much function of the feet comparted to the
hand. So it is lot easier to pick up structures
with your hands than it's with your feet.
However the main benefits of the upper limb
being its mobility, isn't the same as the
lower limb because it doesn't need to
be as mobile and the lower limb is important
for stability. So you don’t have a greater
range of movements, but it is important in
being able to make sure your posture is correct.
Being able to support the entire weight of
your trunk. So there is a battle between the
upper limb and the lower limb. The Upper limb
increasing mobility but it has got a high
level of instability. So it is more prone
to having dislocated shoulder joints.
There is a whole series of specialized joints
in the upper limb. I have mentioned one of
them the shoulder joint and we will see that
in this lecture series. But the elbow joints
and various joints most distally are very
specialized allowing for this increased
range of movements. As I mentioned also the
axial skeleton is connected to this appendicular
skeleton via the pectoral girdle and we can
see that in the next few slides.