respiratory circulation Flashcards
3 components of the circulatory system
pump - heart / contractile vessels,
vessels - vascular system,
medium - blood / haemolymph
what animals use open circulation
arthropods and some molluscs
how does open circulation work
pump with artery that leads in to haemocoel or open body cavity
then flows into veins and returns to pump
what animals use closed circulation
molluscs, annelids, cephalopods and vertebrates
describe the size of blood vessels in a closed system
large diameter arteries and veins promote rapid flow
small diameter capillaries create leisurely flow in the diffusion zone
what are 2 types of circulatory pump and what animals use them
peristaltic heart - arthropods and annelids
chambered heart - vertebrates, many arthropods and molluscs
how does a peristaltic heart work
a series of contractions of muscles to move fluid in one direction = peristaltic wave
what separates the chambers in an arthropods heart
ostia
how many chambers in a fish heart and how many of these are pumping chambers
4
2 which pump
how many pumping chambers in a double circulatory system
4
explain the role of the ventricles
R ventricle pumps blood to lungs to be oxygenated
L ventricle pumps blood around body once oxygenated
where is the tricuspid valve
between the R atrium and ventricle
what valve lies between the left atrium and ventricle
mitral valve
where is the pulmonary valve located
between the R ventricle and pulmonary artery
what valve lies between the L ventricle and aorta
aortic valve
what is responsible for initating contractions in the heart
pacemaker cells
what is the main pacemaker
sinoatrial node
which node propegates action potentials to ventricles
atrioventricular node
how does the atrioventricular node stimulate contraction of the ventricles
through the purkinje fibres
explain the electrical flow in the heart
calcium ions move in making membrane less negative = depolarisation
action potential crosses threshold triggering influx of calcium ions = large depolarisation
calcium ion gates shut, large movement of potassium ions out of membrane
how does the efficiency of amphibian circulatory system compare to mammals and birds
less efficient
how do arteries maintain high velocity flow
elastic recoil
what is the role of arterioles
control flow via constriction and dilation
what do capillaries have to maintain unidirectional flow
sphincters
how many chambers in an amphibian heart
3
what are 4 components of blood
plasma,
ions,
nutrients,
waste,
gases,
proteins,
lipoproteins,
cells and cell fragments
what are 4 components of haemolymph
water,
ions,
nutrients,
waste,
gases,
proteins,
lipoproteins
what are the immune cells found in haemolymph
hemocytes
what can be found in the haemolymph instead of red blood cells
respiratory pigments
what is the respiratory pigment in vertebrates
haemoglobin
what metal is in haemoglobin
iron
what animal has the smallest haemoglobin molecule
hagfish
what is the only adult animal lacking haemoglobin
Antarctic icefish
what is the structure of vertebrate haemoglobin
4 polypeptide chains arranged in a tetramer
what is different about bird haemoglobin
still has nucleus and other organelle
what is the respiratory pigment in molluscs, cephalopods and annelids
haemocyanin
what metal is haemocyanin made of
copper
is oxygen binding in haemoglobin reversible
yes
what is P50 a measure of
partial pressure of oxygen required for 50% oxygen saturation
what is myoglobin
monomer with high oxygen affinity, storing oxygen in muscles
what polypeptide chains are found in fetal haemoglobin that are not present in adults
gamma chains
what form is carbon dioxide transported in the blood
as bicarbonate
what true about fetal haemoglobin in comparison with the mother
fetal haemoglobin has higher affinity for oyxgen in order to take oxygen from the mothers blood
where is carbon dioxide transported
in plasma as it has higher solubility
what is the reaction between carbon dioxide and water
Bohr effect
what catalyses the reaction between carbon dioxide and water
carbonic anhydrase
in the reaction between water and carbon dioxide, protons are produced. Where do these bind to and why
bind to haemoglobin so that blood does not become more acidic
what happens to haemoglobin when back at the lungs and what is the name of this effect
oxygen binds to haemoglobin causing carbon dioxide and protons to be released
= Haldane effect
what are 4 modulators of oxygen affinity
carbon dioxide,
temperature,
pH,
organic phosphates (ATP, DGP)
what is the effect of having high P50
haemoglobin has higher affinity and releases more oxygen more readily at tissues
what has higher P50 - small or large mammals
small
