We can also in relation to the radial groove see the origin
of the medial and lateral heads of triceps.
Neurovascular relations are important on this
posterior compartment. I'll talk about the ones
that are passing up to through scapula in
more detail when we look at the blood supply to
the upper limb. But really I just want to
focus in, these muscles apart these blood
vessels and nerves which are passing out of
the triangular interval. We can see it here.
Reminding ourselves that the triangular interval
is formed medially by the long head of triceps,
superiorly by the teres major muscle and laterally
by the humerus. We can see these nerves and
these blood vessels are leaving
the axilla and passing to the posterior compartment.
We can see up here, we have the axillary artery
and that is eventually becoming the brachial
artery and coming from the brachial artery
we can see just here, we have the profunda
brachii artery. Here we can pick up the profunda
brachii artery running in between the medial
and lateral heads of triceps. It is accompanied
by if here remember the posterior coat the
radial nerve following the profunda brachii artery.
And we can see the radial nerve now passing
down to this posterior compartment. So remember
the brachial artery as the axillary artery
where in the axilla and the posterior cord
was in the axilla. And to pass out from the axilla to the
posterior compartment these structures had
to pass through one of those spaces.
Here they have passed through the triangular interval.
So separates the long and lateral heads of
triceps we have got the radial nerve and
the profunda brachii artery. They passed
to the posterior compartment via the triangular
interval. Radial nerve from the posterior
cord, the profunda brachii from the brachial
artery. So in this lecture we have looked to
the brachial fascia and the intermuscular
septae that separate the arm into compartments.
We can visualize that with the arm in cross section.
We then looked to the anterior compartment
of the arm, biceps brachii, brachialis, and
coracobrachialis. We looked at the function
and then neurovascular relations. We looked
to the cubital fossa, its boundaries and contents and
then we looked into the posterior compartment
specifically triceps brachii, its function
and the important neurovascular relations.