P5 Assessment
To achieve P5 you need to describe:
•
•
•
The different structures within the heart (i.e. atria, ventricles and so forth).
The different types of blood vessels (such as the arteries) outlining their structure
and function, i.e. thick walls and taking blood away from the heart.
The role of the circulatory system both at rest and during exercise, i.e. delivery of
oxygen to the muscles and removal of waste products.
To achieve M2 you need to explain the
function of the cardiovascular system:
• How does it work?
• How is each part of the system designed to
meet its function?
The Blood Vessels
Introduction
We have a variety of different vessels within the
cardiovascular system to deliver and remove nutrients and
waste products.
Blood in the arteries is bright red, as it is carrying oxygen. It
drops off the oxygen and picks up carbon dioxide as it
moves through the capillaries. By the time it reaches the
veins and venules it is a much darker blue/red colour.
5 main blood vessels
• Arteries
Carry blood away
from the heart
– Arterioles
• Capillaries
Where gas
exchange takes place
– Venules
• Veins
Carry blood back to
the heart
• Arteries are large
blood vessels, that
carry blood away from
the heart.
Arteries & Arterioles
•Thick Elastic muscular walls
Artery walls contain elastic cartilage and
smooth muscle, This allows the arteries
walls to contract and relax to send
blood to all parts of the body
This process is known as
perstalsis, and is how smooth
muscle contracts
•Carry Oxygenated blood
–Apart from the pulmonary artery,
which carries deoxygenated blood to
the lungs to get Oxygen
Arteries & Arterioles
• Small round lumen
• Operate under high
pressure
• Arteries don’t contain
valves, as the blood is
moving quickly under high
pressure, so there is no
chance of backflow.
Aorta
–Main artery leaving the heart
It soon splits into smaller vessels –
Arterioles
–Arterioles deliver the blood to
the capillaries
Smallest blood vessels
– Found in all cells of the body
Just one cell thick
•
Capillaries
Very thin walls
– Allows oxygen and other nutrients to diffuse through the cell walls.
• Blood flows very slowly through the capillaries so that this can
happen
– Effectively in the capillaries, the blood unloads the Oxygen and picks up
carbon dioxide and lactic acid (the waste products of metabolism)
Veins & Venules
• The blood feeds from the
capillaries back to the
venules and then the
veins.
• Larger oval lumen
– Means blood flows at lower
speed and pressure.
• Thinner and less muscular than
arteries
– Have some smooth muscle
• Contracts to help sent the
blood back to the heart
Veins & Venules
• Carry blood back to the heart
– Generally working against gravity
• Particularly blood that is going back to the
heart from the legs or arms, as it is below
the heart.
– Valves
• To prevent the blood from flowing back
once the smooth muscle relaxes.
• Prevents pooling, particularly in the legs
Deoxygenated blood
– Apart from pulmonary vein which carries oxygenated
blood from the lungs back to the heart.
Task…
You are going to outline the function and
characteristics of each of the 6 types of
Blood Vessels that serve the circulatory
system…
Including:
- Physical characteristics that classify
each blood vessel.
- What their function is within the
CIRCULATORY system?
- What do they transport?
Blood
It is the medium in which all the cells are carried to transport
nutrients and Oxygen (O2) to the cells of the body.
It carries:
- Oxygen,
Glucose, Proteins, Fats, Vitamins,
Hormones, Enzymes, Platelets, Carbon Dioxide
and Electrolytes.
Made up of 4 components:
-
Red blood cells
White blood cells
Platelets
Plasma
Plasma: straw
coloured liquid
that all solids
are carried
within.
Red Blood Cells
Red blood cells make up 99% of the
population of the blood cells in the body
They are RED in colour due to the
presence of a protein called
HAEMOGLOBIN and absolutely
loves Oxygen (massive attraction!)
Making RED blood cells soul purpose to transport OXYGEN!
Cells
They are colourless and
transparent and fewer in number
to red blood cells (1:700)
The role of White blood cells is to fight infection
as they are part of the immune system.
They destroy bacteria and other
dangerous organisms… thus
fighting potential infection.
Platelets
They become sticky
when in contact with
air to form the initial
stage of repair to the
damaged tissue…
They act by
stopping blood loss
through clotting
Yet platelets need a substance called
x-Factor 8 to enable them to become
active and do their job/clot.