Circulatory System Physiology Flashcards
in animals all cells must…
-have adequate O2, nutrients
-eliminate toxic byproducts of cell metabolism (CO2, N, etc)
how do some species rely on diffusion directly to/from the environment
the body of these animals is only a few cells thick
why do more complex animals require an internal, rapid transport system
-cells are too far away from environment
ie diffusion is simply not fast enough
-animals may have impermeable skin to prevent dehydration, for protection, support
-so need circ systems
what things need to be transported
-homeostasis and metabolism
-heat
what things need to be transported for homeostasis and metabolism
-water, respiratory gases, nutrients
-waste products and metabolic intermediates and ions
-CO2
-NH3, NH4, uric acid, urea
-lactic acid, HCO3-
-Na+,K+,Ca2+,Mg2+
-blood clotting factors
-chemical messengers: hormones
-antibodies, cells from the immune system
why does the circ system need to transport heat
control of blood flow to the skin and to the extremities plays an important role in controlling and maintaining body temp
what are the four kinds of circulatory systems
-circulation of external fluid through an open body cavity
-circulation of internal fluid through an open body cavity
-circulation of internal fluid through a closed body cavity
-circulation of internal fluid through a closed circulatory system with a double circuit
how does circulation of external fluid through an open body cavity work
through a thin layer of cells
how does circulation of internal fluid through an open body cavity work
circulation through tubes plus the body (celomate)
how does circulation of internal fluid through a closed body cavity work
-with a systematic circuit
-single circuit (never leaves blood vessels)
what are some features of circulation through open body cavity
-simplest
-uses water currents, beating of flagula, movement of hydra to bring water in, bring in nutrients, release waste
what animals is circulation through an open body cavity found in
sponges and cnidarians
what an open circulatory system found in
many invertebrate animals
how does a open circ system work
-blood pumped by heart empties into an open fluid space
-has a heart
-blood vessels open to the animals body cavity–>hemocoel
what is a hemolymph
-it is found in open circ systems and it is blood + interstitial fluid
-a fluid analogous to the blood in vertebrates
what is the hemocoel
-hemocoel space or cavities in body tissue
-blood opens right into it, no distinction between interstitial fluid and blood
explain the flow of blood in the open circ system
pump(all hearts openings are controlled by valves)–>artery–>hemocoel–>vein–>pump
how well does the open circ system alter the direction or velocity of blood flow
it has limited ability
how well does open circ system transfer O2
-it has a low rate of O2 transfer
-insects are an exception and not involved in O2 transport
what are the functions of the insect haemolymph
-transport of nutrients, hormones, waste products, and immune molecules
-haemolymph cells involves in wound repair and immune response
-hydraulic skeleton->specially in larvae
-heat transfer
what does hemolymph contain
-hemocyanin in many animals
what is hemocyanin
-found in hemolymph
-metalloprotein with 2 copper atoms
-major O2 transporter in invertebrates
-reversibly binds a single O2
-not bound to blood cells
-suspended in the hemolymph
what colour is hemocyanin
-colourless Cu (I) deoxygenated
-blue Cu (II) oxygenated form
for the closed circulatory system most species share common elements in most species
-a fluid (solutes in solution, cells in suspension)
-a pump to move fluid (usually a heart)
-vessels to carry the fluid between the pump and body tissue
what is latin for vessels
vascular (latin; small vessels)
where is the closed circulatory system found
all vertebrates and some invertebrates (cephalopods-squid, ocoto)
how does blood flow in a closed circ system
-in a continuous circuit of tubes
-heart–>artery–>small diameter blood vessels where exchange of gases, nutrients, and water takes place–>veins–>heart
who is a closed circulatory system ideal for
larger animals–>blood reaches all cells
what do capillary beds allow for
fine control of blood distribution and increase delivery of oxygen to tissue very rapidly
what are the three kinds of closed circulations in vertebrates
-single circulation (fish)
-parallel circulation (amphibians)
-double circulation (mammal, birds and crock)
how many chambers does the heart of a amphibian have
3 chamber, 2 atria, 1 ventricle
how many chambers does the heart of lizard, snake, turtles have
3
how does fish circulation work
-undivided (single circuit) heart
-blood in oxygenated before going to body
-higher BP then in open system
-but BP is still low
what is the BP of a fish like
-higher BP then in open system
-but BP is still how
-low to avoid fluid leakage
-BP=30/20
what is the circulatory system of most reptiles like (snakes, lizards, turtles)
-partially divided heart
-blood is still oxygenated before going to the body
-BP=30/20
-but one pump = one BP
what is the circulatory system of crocodiles, birds, and mammals like
-completely divided (double circuit)
-blood is still oxygenated first
-but now two pumps=two BP
-BP=30/20 (pulmonary)
-BP 120/80 (systematic)
-means high velocity to systematic tissues
-supports high rates of cellular respiration (metabolism)
what are the two different BP in the mammal, bird, crock system
-30/20, pulmonary, low pressure/low resistance system
-120/80, systemic, high pressure/high resistance system
many insects especially flying ones maintain a high metabolic rate despite having an open circulatory system and being ectothermic how do that do that
they use spiracles to breath they dont use circulatory systems to transport O2
what are the parts of the mammalian heart
-a four chambered pump
-two atria at top of heart
-two ventricles at bottom of of heart
-atrioventricular (AV) valves between atria and ventricles
-semilunar (SL) valves between ventricles and aorta/pulmonary arteries
how is blood pumped in the mammalian heart
-in two separate circuits
-pulmonary (right heart)
-systemic (left heart)
how do valves open and close in the human heart
due to pressure
what is the point of heart valves in human heart
prevent packflow
what makes the heart sound
the closing of valves
what is myocardium and what side is it more abundant on
-cardiac muscle
-more muscular on left side as opposed to right
why are semilunar valves called semilunar
3 cusp like structures
explain the opening and closing process of the semilunar valve
-when pressure is greater behind the valve it opens
-when pressure is greater in front of valve it closes. note that when when pressure is greater in front of the valve it does not open in the opposite direction because it is a one way valve
-passive process which is the change in gradient
what are the two different ways the cardiac cycle can be initiated
-neurogenic hearts (in some crustaceans) which beats under control of nervous system
-myogenic hearts (all other animals) contractions initiated within the heart
what is the heart contraction cycle
-its highly coordinated
-both atria first
-followed by both ventricles
-ventricles contract bottom upwards
-alternating periods of:
diastole (relaxation)
systole (contraction)