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0:00
My name is Larissa Nelson,
and I'm a senior lecturer of
anatomy at Cardiff University.
0:08
In this talk, I will
give an overview of
the vascular and
lymphatic systems.
By the end of this talk,
you should be able to
describe the basic
structure and function of
the cardiovascular
and lymphatic systems
and you should be
able to explain
how the lymphatic system
complements the vascular system.
0:26
As a starting point, it's
important to understand
what we mean by the
circulatory system.
Often people assume the
circulatory system refers to
the cardiovascular system or
the circulation of blood
throughout the body.
Whilst it does encompass this,
the circulatory
system consists of
two separate systems
that are closely linked
working together to
maintain fluid balance,
transport substances
around the body
and support immunity.
These are the cardiovascular
and lymphatic systems.
As a part of these two systems,
we have the vascular
system, which usually
refers to the network of
vessels that transports fluids.
1:02
While the focus of this talk
will be on the vascular system,
it's important to
place this within
the context of the wider
cardiovascular system
as the blood vessels and
the heart work together
to maintain circulation
throughout the body.
Here we will begin by covering
the cardiovascular system,
which is a closed
system that comprises
the heart, blood,
and blood vessels.
Through this transport
network, the heart,
which is a muscular organ
that lies within the thorax,
propels the blood through
a series of vessels,
allowing the transportation
of materials,
such as oxygen from the lungs,
nutrients from the gastrointestinal
tract and hormones.
As the blood is pumped
through the system,
the blood vessels
are specialised
in order to adapt to the
function required of them.
Arteries carry blood
away from the heart.
In the systemic circulation,
this blood is
usually oxygen-rich.
These arteries
divide progressively
into smaller arteries
which eventually
become even smaller arterioles.
These arterioles enter tissues,
themselves branching into
tiny vessels called capillaries.
The capillaries are
the site of exchange
of nutrients and waste products
between the circulation and
the interstitial fluid
surrounding cells in the body.
They're the smallest
of the blood vessels.
The capillaries reunite
to form small vessels
called venules, carrying
blood back towards the heart.
In the systemic circulation,
this blood is typically
lower in oxygen
and contains metabolic
waste products.
These venules progressively form
larger blood vessels
called veins.
Structurally, the walls of
these different vessels
have adapted to allow them to
carry out their
function maximally.
These differences will be
outlined later on in my talk.
Whilst understanding
the structure
