Zusammenfassung der Ressource
Blood Vessles/Erythrocytes/Tissue fluid
- Veins and Venules
- The tunica externia consists of mainly collagen fibres
- Tunica externia
- The walls are mainly made out of collagen
because blood is pumped at low pressure
- Tunica media is very thin and contains some smooth muscle and elastic fibres
- Tunica media
- This is much less elastic due to the less in
pressure to pump blood. Unlike Arteries, the
tunica media needs to be thicker.
- Lumen is large so there is less resistance to blood flow
- Lumen
- Blood is mainly deoxynated apart from the pulmonary vein
- Cappillieries
- These are only one cell thick, the lumen is just enough for the RBC to pass.
- Cappillieries make sure that there is exchange
between materials between the blood and the
tissues
- The wall is made out of endothelium
- Blood changes to oxynated to deoxynated (except the lungs)
- Arteries and Arterioles
- Arteries have a much bigger tunica
externa which is made out of collagen
fibres and some elastic fibres
- Contains elastic fibres because arteries pump blood away
from the heart and to the lungs at high pressures
- Tunica externia
- The tunica media is much more thicker
and contains smooth muscle tissue,
collagen fibres, and elastic fibres
- Tunica media
- The tunica intima, contains endothelium
which is a very smooth single layer of cells
- Tunica intima
- Blood is mainly oxynated apart from the pulmonary artery
- Arteries expand during systole and relax after diasytole
- Red blood cell/Erythrocytes
- Red blood cells have no nucleus, they are also biconcave in shape which
makes them easier to flow through blood flow.
- Red blood cells have haemoglobin which combines to oxygen to produce oxyhaemoglobin
- They combine when there are areas with high concentration of oxygen and release it when there
are areas of low concentration e.g picks up oxygen in the lungs and releases it into the tissues
- Function of the Erythrocytes
- They have a large surface area : volume ratio which
means that the surface area is large so the RBC can
fit much more haemoglobin onto it.
- They are small in size which means that they can rapidly
pick up oxgen because RBC's are close to the surface
- Containing no nucleus means that there is much room for
more haemoglobin to fit onto the cell.
- Tissue Fluid
- Blood Plasma
- Blood plasma is like tissue fluid however contains a lot more proteins, placelets, and
leucocytes(WBC)
- The difference between