mass transport in animals Flashcards
(29 cards)
circulatory system
vena cava, right atrium, right ventricle, pulmonary arteries, lungs, pulmonary veins, left atrium, left ventricle, aorta
arteries
-thick elastic walls to withstand high blood pressure
-carriers blood away from the heart
-thick muscle wall allows constriction and dilation
-relatively small lumen
-smooth muscle and smooth endothelium to reduce friction and ease flow of blood
arterioles
-branch off from arteries
-connects arteries to capillaries
-relatively thick muscle layer
-vasoconstriction and vasodilation
-elastic layer thinner as blood pressure is lower
capillaries
-large SA:V ratio
-once cell thick
-gas exchange
veins
-low pressure
-typically deoxygenated
-carries blood back to the heart
-thin walls
-wide lumen
-semi lunar valves
-prevents back flow
haemoglobin
-transports oxygen
-pigment molecule
-haem part can temporarily bond with 4 O2 molecules
-haem, Fe2+
-2 beta chains and 2 helixes
-water soluble globular protein
-
oxyhaemoglobin
-in oxygen rich situations (capillaries in lungs) Hb and O2 combine and forms oxyhemoglobin
-in oxygen poor situations (capillaries of exercising muscles) oxyhemoglobin dissociates and releases the oxygen
positive cooperatively
-Hb is a dynamic protein
-first oxygen difficult to bind due t close unity of the polypeptide chains
-changes the quaternary shape when it does bind
-the binding of one oxygen molecule increases the ease for the second and third to bind
sigmoid curve
-Y Axis hameoglobin saturation
-X Axis partial pressure of oxygen
-dissociation pattern is ket to its functionality
-high conc, lots of molecules to bind to Hb
-low conc, molecules released from Hb
-association/dissociation happens over a small window of oxygen concentration change
high affinity
Hb binds easily and doesn’t release easily
low affinity
Hb struggles to bind and releases easily
lugworms affinity for oxygen
low oxygen concentration in the seawater holes they live in, more oxygen can bind at a lower pO2, Hb has a high affinity for oxygen, amino acid sequence change
hawks affinity for oxygen
low oxygen content of the atmosphere at high altitudes, high oxygen demand in muscles, Hb has a low affinity for oxygen so readily given to respiring tissue, amino acid sequence order
bohr effect
-more respiration=more CO2 produced
-CO2 dissolves in blood
-CO2➡️H2CO3➡️H+HCO3
-as there are more H+ ions in the blood, this alters the pH which alters the shape of the protein Hb
-oxygen dissociation curve shifted to the right
-lower affinity
-releases more O2 molecules for the same partial pressure
both effect in the lungs
-opposite is true
-lower concentration of CO2 in the lungs
-curve is moved to the left
-high affinity for oxygen
pressure in the heart
-pressure high to low
-humans and animals have evolved a way to generate positive pressure
-one organ responsible
-contracts, decreases volume and increases pressure
-forces transport medium around the system
systole
period of muscle contraction
diastole
period of muscle relaxation
cardiac diastole
-atria and ventricle relax
-elastic recoil lowers pressure inside chambers
-blood returns to the heart from the vena cave and pulmonary vein to fill the atria
-pressure increases inside the atria until AV valve opens
-blood flows into ventricles
-relaxed atria and ventricle means that semi lunar valves are closed
atrial systole
-heart is full of blood and ventricles are relaxed
-both atria contract and blood passes into ventricles
-the AV valve opens due to blood pressure
-70% of blood flows passively
ventricular systole
-atria relax
-ventricle walls contract forcing blood out
-AV valves close and semi lunar valves open
-blood leaves the left ventricle through aorta
-blood leaves the right ventricle through pulmonary artery
stroke volume
amount of blood that the left ventricle pumps out each time it beats
heart rate
the number of times the heart beats in a minute
cardiac output
stroke volume x heart rate
