transport in animals Flashcards
why do multicellular organisms need transport systems?
they are relatively big, low surface area to volume ratio, higher metabolic rate, very active meaning a large number of cells are respiring very quickly so they need a constant, rapid supply of glucose and oxygen
which circulatory system do fish have?
closed single circulatory system
which circulatory system do mammals have?
closed double circulatory system
what is an advantage of the double circulatory system?
heart can give the blood an extra push between the lungs and the rest of the body, blood travels faster and oxygen is delivered to the tissues more quickly
which circulatory system do some invertebrate’s (insects) have?
open circulatory system
what do arteries do?
carry blood from the heart to the rest of the body
what are 4 things that make up the arteries?
elastic tissue wall
thick muscle layer
lumen space
folded epithelium
what is the structure of capillaries?
one cell thick
what do the veins do?
take blood back to the heart under low pressure.
what is the structure of veins?
large lumen, endothelium and thin muscle wall
what type of blood do veins carry
deoxygenated blood as 02 has been used up by body cells
what type of blood do pulmonary veins carry
oxygenated
what type of blood do pulmonary arteries carry?
deoxygenated blood
what type of blood do other arteries carry?
oxygenated blood
what are six things the blood has?
RBC
WBC
PLATELETES
PROTEINS
WATER
DISSOLVED SOLUTES
what are 4 things the tissue fluid has?
very few wbc (for infection
very few proteins
water
dissolved solutes
what are 4 things the lymph has?
wbc
antibodies (proteins)
water
dissolved solutes
what does the right side of the heart do?
pumps deoxygenated blood to the lungs
what does the left side of the heart do?
pump oxygenated blood to the rest of the body
formula for cardiac output (calc for volume of blood pumped by heart cm3min-1)
heart rate x stroke volume
define tachycardia
when the heartbeat is too fast, heart isn’t pumping blood efficiently, 120bpm higher
define brachycardia
too slow, below 60 bpm
define ectopic heartbeat
extra heartbeat, caused by an earlier contraction of the atria, can also be cause by early contraction of the ventricles
define fibrillation
a really irregular heartbeat
atria or ventricles completely lose their rhythm and stop contracting properly
how is oxyhaemoglobin formed
when oxygen joins to the iron in haemoglobin
whats the equation for oxyhaemoglobin
Hb + 4O2 = HbO8
affinity definition
tendency to combine with oxygen
what is the partial pressure of oxygen?
measure of oxygen concentration
what happens when there is a high partial pressure of oxygen?
oxygen loads onto haemoglobin to from oxyhaemoglobin
what happens when there is a low partial pressure of oxygen?
oxyhaemoglobin unloads its oxygen
why does fetal haemoglobin have a higher affinity for oxygen rather than the adult haemoglobin?
fetus gets oxygen from its mothers blood across placenta
by the time mothers blood reaches placenta, its O2 saturation has decreased
for fetus to get enough oxygen to survive, it needs to have a higher affinity for O2
describe the Bohr effect
when carbon dioxide levels increase, the dissociation curve shifts right, showing more oxygen is released from blood
how does CO2 affect oxygen unloading?
in RBC, carbon dioxide reacts with water to produce carbonic acid catalysed by the enzyme, carbonic anhydrous
carbonic acid dissociates to give hydrogen ions and hydrogenation ions
the increase in hydrogen ions causes oxyhaemoglobin to unload its oxygen so haemoglobin can take up hydrogen ions,
this forms haemoglobinic acid (the process also stops increasing acidity of cells)
hydrogen carbonate ions diffuse out of RBC and transported to blood plasma.
to compensate the loss of HCO3- ions, CL- ions diffuse into RBC, this is called the chloride shift maintaining balance if charge between RBC and the plasma
when the blood reaches lungs, the low partial pressure of carbon dioxide causes some HCO3- and H+ ions to recombine into CO2 and water
the CO2 then diffuses into the alveoli and is breathed out
