Mass Transport in Animals Flashcards
What are the two components of blood?
liquid plasma and cells
What is plasma?
transports dissolved glucose, amino acids, urea, ions and hormones
What are the majority of the cells in the blood?
red blood cells
What are the other type of cells in the blood?
white blood cells- invloved in the immune response
Why are the porportions of the comonents of the blood important?
there has to be enough plasma for the blood to flow, a small decrease and the blood becomes viscous and the heart has to pump harder.
What is the human heart?
The double pump of the double circulatory system (blood passes throught the heart twice)
What are arteries?
And what are their properties?
Take blood away from the heart.
Thick, flexible walls
inside wall- flattened cells to reduce friction
Middle wall- muscle cells and elastic fibres
outside- layer of tough protein fibres.
What are veins and their properties?
Take blood to the heart.
Thinner walls
Lower blood pressure
valves
wider lumen
What are capillaries?
8 micrometres in diameter
larger SA
Short diffusion distance
Which vessels enter the heart?
vena cava
pulmonary vein
Which vessels leave the heart?
pulmonary artery
aorta
Which vessels enter the kidney and which leaves?
enters- renal artery
leaves- renal vein
What are the location and function of the coronary arteries?
wrap around the outside of the heart.
sends blood flow to the heart.
What is cardiac muscle consisted of?
branced myofibrils separated by intercalated discs
What is heart rate?
the number of cardiac cycles per minute
What is stroke volume?
the volume of blood pumped out of the left ventricle during one cardiac cycle.
What is cardiac output?
the volume of blood the left ventricle pumps out to the body per minute.
What is coronary heart disease?
any condition that interferes with the coronary arteries that supply blood to the heart muscle
occurs when they become blocked by fatty diposits.
What is the cardiac cycle?
the sequence of stages that happen during one heartbeat
What is systole?
the stage in the cardiac cycle when the muscles of the heart chambers are contracting
What is diastole?
the relaxation of the muscles
What are the three stages of the cardiac cycle?
Atrial systole
Ventricular systole
Diastole
What happens during the artial systole stage?
atrial msucle contracts
blood forced through the atrioventricular valves into ventricles
What happens during the ventricular systole stage?
ventricle muscles contract
blood forced throuhh valves into arteries
What happens during the diastole stage?
muscles of the ventricle relax
What does contraction of the muscles cause?
walls of ventricles create pressure, higher of that in the aorta and pulmonary artery, forcing open the valves.
What does relaxation of the ventricle muscles cause?
walls recoil, increases volume, reduces pressure and semi-lunar valves shut
How does blood flow back to the atria?
At a much lower pressure, walls relaxed, as atria fill, some blood passes through the valves, as they fill more, the walls contract and forces valves fully open
What is the vena cava?
superior and inferior
Brings blood back from the body
What is the aorta?
carriers blood from heart to around the body
What is the pulmonary artery?
carries blood from the heart to the lungs
What are the pulmonary veins?
returns blood from the lungs
What are the semi-lunar valves?
Prevent backflow into the ventricles as blood leaves the heart, e.g. the aortic valve
What are the atrioventricular valves?
Tricuspid on right side of heart
Bicuspid on left side of heart
-Prevent backflow into atria.
What are the coronary arteries?
Wrap around the outside of the heart.
Sends blood to the heart muscle
How to calculate cardiac output?
stroke volume x heart rate
What does myogenic mean?
myogenic muscle can generate its own contraction and does not need to be stiumlated by a nerve.
Caused by the atrioventricular and sinoatrial node
What does an ECG measure?
electrical change
what does an ECG look like
first small bump- atria depolarising, then av node delyaed, then the sharp rise is the ventricles depolarising, then the next bump is the ventricles repolarising.
How is blood adapted to transport oxygen?
small size - 7 micrometres, reduces diffusion distance
flattened disc shape- increases SA:V ratio and short diffusion pathway
Thin central part of disc- flexible, edges scrape on walls of cappilairy
absence of organelles- maximum space for haemoglobin
haemoglobin - increases the oxygen carrying capacity of blood
What is the structure of haemoglobin?
4 polypeptides (globins) with a haem group
Haem contains iron ion (Fe2+)
What is oxyhaemoglobin?
When each haemoglobin combines with a maximum of four molecules of oxygen - 100% saturated if all have combined.
What is the oxyhaemoglobin dissociation curve?
s - shaped
shows how much oxygen is combined at different partial pressures of oxygen
What is partial pressure?
How much oxygen is available to haemoglobin
What is cooperative binding?
where haemoglobin molecules change shape and load with oxygen more easily once the first oxygen has combined.
makes the s shape
What is the Bohr effect?
change in position of the dissocaition curve due to an increased concentartion of CO2
occurs in active muscles
