Transport (humans) Flashcards
What are the four things blood consists of?
Red blood cells, white blood cells, platelets and plasma
What percentage of the total volume of blood does each of the four things make up?
Red blood cells: 45%
Plasma: 55%
Platelets and white blood cells: <1%
What is plasma?
A straw coloured liquid in which other components of blood are suspended in
It is also what all other substances transported by the blood and suspended in, and it is necessary to transport these substances around the body
Which substances are transported in blood plasma?
Carbon dioxide
Digested nutrients (including mineral ions)
Urea
Hormones
Heat energy
Oxygen is carried in the red blood cells, not plasma
Plasma is comprised of 90% water, so it also carries water
What are the adaptations of red blood cells that make them suitable for the transportation of oxygen?
They are full of haemoglobin, a protein which binds to oxygen
They have no nucleus to allow for more space for haemoglobin
They are small and have a bioconvave disk shape which allows them to have a small surface area to volume ratio for optimal diffusion
What is the pathway of blood through the heart?
Vena Cava
Right atrium
Tricuspid valve
Right ventricle
Semilunar valve
Pulmonary artery
Lungs (oxygenated)
Pulmonary vein
Left atrium
Bicuspid valve
Left ventricle
Semilunar Valve
Aorta
Why are there thicker muscular walls on the left ventricle of the heart?
It must pump blood a much further distance (around the whole body) at a high pressure, compared to the right ventricle which only needs to pump it to the lungs
What are valves for in the heart?
Preventing backflow
What is the septum for in the heart?
Dividing the right and left ventricle and stopping the oxygenated and deoxygenated blood from mixing, which could cause blood being pumped to the rest of the body to be less oxygenated
What happens to heartrate during exercise and why?
It increases
More muscular contractions lead to increased need for respiration
More glucose and oxygen must be supplied, and more carbon dioxide (and potentially lactic acid) must be removed due to increased respiration
What happens to heartrate under the influence of adrenaline and why?
It increases as more blood with oxygen and glucose is pumped to the muscles in preparation for running/fighting
What are the factors that increase the risk of developing coronary heart disease?
Obesity - Extra weight puts strain on heart, and if the person has diabetes, this can damage blood vessels
High blood pressure - Increases force of blood against vessels, damaging them
High saturated fat/cholesterol diet - Is what causes the build up of fatty plaques
Smoking - Can contribute to plaque build up and increase blood pressure, carbon monoxide can also reduce oxygen carrying capacity, nicotine increases blood pressure
Lack of exercise - Exercise makes heart and circulation better and more efficient and reduces cholesterol and blood pressure
What are the distinct features of arteries?
Carry blood away from the heart
Have a thick muscular and elastic wall to carry blood at high pressure
Have a small lumen to maintain a high pressure
Carry oxygenated blood, apart from the pulmonary artery
Have connective tissue which provides strength
The blood is under high pressure in the arteries because it has just been pumped out of the left ventricle at extreme force
Arterioles are the smaller arties which branch off of arteries
What are the distinct features of veins?
Carry blood towards the heart
Have less muscular, elastic and connective tissue as blood is being carried at lower pressures (as it has not just been pumped out the left ventricle)
Have a large lumen to allow blood to flow at low pressures
Carry deoxygenated blood, apart from the pulmonary vein
Have valves to stop the backflow of blood
They need valves because the blood is at a low enough pressure for backflow to occur
What are the distinct features of capillaries?
Very small to allow them and the blood they are carrying to get up close to organs
Capillary walls are one cell thick and permeable to allow for easy diffusion
What do Phagocytes do?
Phagocytes carry out phagocytosis by engulfing and digesting pathogens
How do Phagocytes work?
Phagocytes have a sensitive cell surface membrane that can detect chemicals produced by pathogenic cells
Once they encounter the pathogenic cell, they will engulf it and release digestive enzymes to digest it
This is a non-specific immune response