The Heart/circulatory system Flashcards
what is the circulatory system
a closed, double circulatory system.
-closed means the blood remains within blood vessels.
what happens to the oxygenated blood from the lungs
-oxygenated blood from the lungs then goes back through the heart to be pumped out at a high pressure to the rest of the body.
- this is important to ensure that the blood reaches all the respiring cells in the body.
blood vessels
- many blood vessels within the circulatory system
- coronary arteries main blood vessels to know
what does the double circulatory system refer to
- the fact that blood passes through the heart twice in each circuit.
-there is one circuit which delivers blood to the lungs and another circuit which delivers blood to the rest of the body.
the coronary arteries and the following blood vessels are attached to which organs?
-Heart (vena cava, aorta, pulmonary artery and pulmonary vein )
-lungs ( pulmonary artery and pulmonary vein)
-kidneys ( renal artery and renal vein)
these major blood vessels are connected within the CS via the arteries, arterioles, capillaries, venules and veins.
Look at diagram in notes.
The tips to remembering the terms
-term pulmonary refers to lungs
-term renal refers to kidneys
-Arteries carry blood Away *(a for away) from the heart into the arterioles
-the veins carry blood back into the heart ( veIN carry blood IN|)
the capillaries
diagram in notes.
-arterioles are smaller than arteries and connect to the capillaries.
-the capillaries connect the arterioles to the venules and then to the veins.
arteries and veins
muscle wall
-arteries have a thicker muscle layer
-so that constriction and dilation can occur
-to control the volume of blood
veins have a relatively thin muscle layer so cant control the flow of blood.
arteries and veins
elastic layer
diagram in notes
arteris have a thicker elastic layer
-help maintain blood pressure
-the walls can stretch and recoil in response to the heart beat
veins have a relatively thin elastic layer
- as pressure is much lower
arteries and veins
wall
diagram in notes
-arteries have a thicker wall
-help prevent vessels from bursting due to high pressure
-the thinness of the walls in the veins means the vessels are easily flattened.
-which helps the flow of blood up to the heart.
- veins also have valves to prevent backflow of blood by ensuring the blood only flows down pressure gradients to ensure blood returns to the heart.
capillaries
diagrams in notes
-capillaries form capillary beds at exchange surfaces
capillary beds are many branched capillaries
-these all have a narrow diameter to slow blood flow
capillaries
red blood cell
diagram in notes
-red blood cells can only just fit through and are squashed against the walls
-this maximises diffusion by shortening the diffusion pathway
what is hemoglobin
-hemoglobin’s are a group of proteins found in different organisms.
-hemoglobin is a protein with a quaternary structure
-hemoglobin and red blood cells transport oxygen
hemoglobin in unloading and loading of oxygen
-variations in loading, transport and unloading of oxygen is based on the conditions and the particular form of hemoglobin. This can be presented on an oxyhemoglobin dissociation curve
the affinity of the haemoglobin for oxygen
the ability of haemoglobin to attract or bind to oxygen.
saturation of haemoglobin with oxygen
the ability of haemoglobin to attract or bind to oxygen
loading/ association of haemoglobin
the binding of oxygen to haemoglobin
unloading/ dissociation of haemoglobin
when the oxygen detaches or unbinds from haemoglobin.
oxyhemoglobin curve
oxygen is loaded in regions with a high partial pressure of oxygen e.g respiring tissues
this is shown on the oxyhaemoglobin curve
co-operative binding
affinity haemoglobin has for oxygen changes depending on how many oxygen molecules are already associated
-haemoglobin can associate with, or load four oxygen molecules and as each molecule binds the shape of the haemoglobin changes making the binding of further oxygen molecules easier.
