transport in humans Flashcards
what is the primary function of red blood cells?
it transports oxygens from the lungs to respiring cells
what are the features of the rbc and how it aids function?
-biconcave shape=greater surface area to volume ratio for an increased rate of diffusion of oxygen into and out of the cell
-contains haemoglobin=haemoglobin binds reversibly to oxyegn
-lacking most organelles=more space to pack more haemoglobin in the cell&no mitochondria to use up oxygen
what is the primary function of a white blood cell?
protect body from diseases and infections
what are the features of the wbc and how it aids function?
-irregularly shaped=allows the cell to squeeze through gaps in the capillary endothelium
-less numerous than rbc=increases in numbers when fighting pathogens
what is the function of phagocytes?
ingest foreign matter like bacteria and viruses
what is the function of lymphocytes?
produce antibodies that bind to and neutralise toxins
what are wbcs responsible for as well?
they are responsible for organ rejections after transplants
wbc can detect and destroy all foreign substances, they may recognise the cells of the newly transplanted organ as foreign and begin destruction process to get rid of all foreign substances from the body
how to avoid tissue rejection?
tissue matching using blood types and many genetic markers
or
use patients own stem cells and genetically engineer them to develop into the organ required
what is the primary function of platelets?
initiate the blood clotting process
-prevent excessive blood loss
-prevent entry of pathogens
what are the feature(s) of platelets?
small fragments of cytoplasm
what are the steps in the blood clotting process?
-platelets and damaged tissues release enzymes
-enzymes convert soluble fibrinogen into insoluble fibrin strands
-fibrin strands form a mesh over the wound to trap rbc and form a clot
what is the primary function of plasma?
medium for transport
what are the features of plasma
pale yellow fluid that is 95% water
what are the substances transported? (plasma)
useful:
-nutrients(glucose, amino acids)
-vitamins(A-E, K)
-hormones(testosterone, oestrogen, insulin)
-proteins (albumin, antibodies, enzymes)
-ions (calcium, iron, sodium)
not useful:
-urea
-co2
what do blood vessels in the body form?
a continuous network of tubes for blood to flow to and from the various organs
what do the arteries do?
they transport blood away from the heart
what do veins do?
they transport blood towards the heart
what do capillaries do?
they allow substances to be exchanged between blood and body cells
what is the vessel wall, lumen diameter, vessel diameter, presence of valves in the arteries?
thick and elastic muscular wall, narrow, large, absent
what is the vessel wall, lumen diameter, vessel diameter, presence of valves in the veins?
thin muscular wall, wide, large, present
what is the vessel wall, lumen diameter, vessel diameter, presence of valves in the capillaries?
one-cell thick endothelium, very narrow, very small. absent
what is the direction of flow, oxygen content, carbon dioxide content, blood pressure and speed for arteries?
away from heart, high except for pulmonary artery. opposite of oxygen content, very high
what is the direction of flow, oxygen content, carbon dioxide content, blood pressure and speed for veins?
towards heart, lower except for pulmonary vein, opposite of oxygen content, low
what is the direction of flow, oxygen content, carbon dioxide content, blood pressure and speed for capillaries?
through the organ, variable, opposite of oxygen content, low
liver to the heart?
hepatic
lungs to the heart?
pulmonary
kidneys to the heart?
renal
what does the pulmonary circulation do?
they ensure that blood is constantly refreshed with oxygen and prevents build-up of co2 which is toxic at high concentrations
what does the systemic circulation do?
they ensure that body cells receive enough oxygen as quickly as possible, as well as remove metabolic waste from the organs to be excreted
what is the feature of the atrial wall and its function?
atrial walls are thinner and less muscular than ventricular walls
f: atria only need to pump blood to adjacent ventricles while ventricles pump blood out of the heart
what is the feature of the ventricular walls and its function?
left ventricular wall is thicker and more muscular than the right ventricular wall
f: left ventricular needs to force blood out at higher pressure over a greater distance to all parts of the body while the right ventricle only needs to pump blood to the nearer lungs
what is the feature of the septum and its function?
septum prevents mixing of blood from across chambers
f: ensures that oxygenated blood in the left ventricle does not mix with deoxygenated blood in the right ventricle, which would result in less oxygen transported to body cells
how long does a typical cardiac cycle last for?
600 milliseconds
what happens when the muscles of a chamber contract?
pressure of the chamber increases (vice versa)
how does blood flow?
from a region of higher pressure to lower pressure
why do valves function?
to prevent excessive backflow of blood by snapping shut
what is the name of the heart’s set of blood vessels?
coronary circulation
what do the coronary arteries do?
they branch off from the aorta to supply the heart muscles with oxygenated blood
what happens when the coronary arteries become blocked/narrow?
the heart muscles receive less oxygenated blood and may die, resulting in a heart attack
what are the factors that increase the chances of a person suffering from coronary heart diseases?
-unhealthy/unbalanced diet
-excessive stress
-smoking
what is a rising cause of coronary heart disease?
frequent consumption of foods high in fat and cholesterol is a rising cause of coronary heart disease. the excess fat and cholesterol accumulate in the bloodstream and may deposit on the inner walls of the coronary arteries
the lumen of the arteries narrow and eventually become entirely blocked, cutting off blood supply to the heart muscles
without glucose and oxygen to respire and release energy, the muscles cannot contract for the heart to pump blood , resulting in a heart attack
how to prevent coronary heart diseases?
leading a healthy and active lifestyle
-healthy and balanced diet (low in saturated fat and cholesterol)
-frequent exercise (maintain healthy levels of fat in the body)
-not smoking (first, second, third hand-smoke are all damaging when inhaled)
