Welcome to this lecture on the Heart. This
is one of my favourite topics in anatomy because
the heart is such an incredible organ. We
really don?t pause and consider how astonishing
the heart is but it?s been estimated that
the amount of work that the heart does in
one?s lifetime is equivalent to lifting
30 tonnes to the top of Mount Everest.
This is coming from a muscle mass of about
300 grams, a little more in the male perhaps
a little less on average in a female. But
the heart does all this work throughout our
lifetime without taking much pause to rest.
An incredible organ. And so please join me
on this tour of the heart.
And as we go on this tour through the heart,
at the end of this lesson you should be able
to answer the following objectives: describe
the pericardium and how the pericardial cavity
and sinuses are formed; compare and contrast
the anatomy of the four cardiac chambers;
list the great vessels and the cardiac chambers
that receive them or issue them; describe
the sulci, surfaces, base and apex of the
heart; describe the cardiac valves with regard
to location and number of cusps; describe
the coronary circulation with regard to dominance
and arterial distribution and then venous
drainage. The last objective you should be
able to answer is: to describe the cardiac
conduction system and the clinical relevance
of Koch?s triangle. And then our summary
slide will identify key messages that you
should take home from this lecture. And then
the last slide will provide attribution for
the images that were used towards this presentation.
This slide is demonstrating the body map.
We have a young, well-developed male. And
our focus will be on the anterior view to
the left. And the topography of the heart
is going to be in this general location. And
so if we peel back the thoracic wall ? the
anterior thoracic wall ? we then can take
a look at how the heart is arranged within
the thoracic cavity.
Here we have an in situ view. So please take
a look at where the heart is. It is located
in this area. It?s in the middle of the
thoracic cavity with the right and left lungs
to either side of it.
It is housed or enclosed within a pericardial
sac. And there are three components that make
up this sac. But here in this view ? in
the in situ view ? you?re seeing the fibrous
pericardium surrounding the heart. The fibrous
pericardium is attached to the diaphragm.
So what that means is, with respiratory movements,
the heart will move with the diaphragm down
and then up, down and then up. And then the
specific location within the thoracic cavity
is the mediastinum ? that area that lies
in the centre ? and the specific area of
the mediastinum that houses the heart and
the pericardium is the middle mediastinum.