cardiovascular - lecture 2 Flashcards
what is comparative physiology
subdiscipline of physiology that studies and exploits diversity of functional characteristics and various kinds of organisms
describe insect circulation gen
dorsal aorta - no closure, open
ostium = pumps, contracts = part of heart
blood enters posterior
valves so wont go back * efficient
always has openings - v simple
fluid pumped is hemolymph not blood
what is hemolymph
circulatory fluid in insects, spiders, crustaceans etc
corresponds to blood and isf in vertebrates
describe circulatory system of insects
does not transport oxygen unlike circulatory system of vertebrates
does not have hemoglobin
respiration carried out by tracheal system
open system with circulation from back to front - due to dorsal vessel made of an aorta and thoracic bulbs (heart)
describe heart part of insects
heart part = small chambers ending in valves called ostiole
this is where hemolymph pumped
valves close with each contraction - allows fluid to move from back to front
describe fish circulation
closed circulation
single loop circulation
2 chambers
gil capillaries = exchange o2, o2 rich and depleted o2 blood, sends blood to gils, feeds organs
describe circulatory system of fish
unlike mammals fish have single heart and not a double heart (no left/right ventricles/atria or venous or arterial)
blood arrives through veins into cavity (atrium) then enters ventricle
ventricle has large muscular wall that allows blood to be sent into artery when contracts
blood reoxygenated at level of gill branches
describe amphibian and most reptilians circulatory system
closed circulation
double loop circulation
3 chambers
other loop for o2 exchange
one ventricle = mixed blood
1 loop for organs - periphery
describe circulatory system of amphibians
closed
2 circulations = small or pulmonocutaneous circuit and large or systemic circuit
heart = 3 chambers, 2 atria, 1 ventricle
what does small circulation do - amphibians
leaves ventricle towards the lungs and skin - places where gas exchange happens
describe blood movement - amphibians
blood enriched in o2 returns to left atrium then passes into ventricle which ejects blood into systemic circ
oxygen depleted blood returns to right atrium then to ventricle to start circuit again
One ventricle – How does that work in terms of oxygen rich vs oxygen depleted blood?
dont get mixed bc structure and pressure of heart = does not need septum
pressure is perfect
not much mixing
describe croc/alligator circulation
2 aortas - allow alligator to function underwater
underwater = less oxygenated blood
describe croc heart
4 chambers = 2 atriums (LA/RA) and 2 ventricles (LV/RV) like mammals and birds
2 aortas = right which connects left ven to systemic circ (like mammals) and a left which connects right ven to systemic circ
describe when underwater - croc/alligator
valve between right ven and pulmonary circ = called gear tooth valve
closed
describe blood movement - croc/alligator
gear tooth valve closes = o2 poor blood from right side of heart to enter left aorta and enter systemic circ
on left side of heart the valve to aorta is also closed and tissues receive blood poor in o2
describe avians and mammalian circ
right heart = pulmonary circ
left heart = systemic circ
closed circulation
double loop circ
4 chambers
describe avians and mammalian heart
4 chambers = 2 atria and 2 ventricles separated by septum
describe avians and mammalian 2 circulations
right side sends blood to lung - pulmonary circ
left side sends blood to rest of body - systemic circ
describe avians and mammalian - unlike amphibians and reptiles
oxygenated blood separated from deoxy = allow better supply of o2 to cells and tissues
we warm blooded
what are hemodynamics
the branch of physiology dealing with the forces involved in the circulation of the blood
the circulation and movement of blood in the body, and the forces involved therein
what is blood volume
5L (75ml/kg)
what is 1 unit of blood
450mL
vol of blood contained in a bag containing a therapeutic dose of blood used for transfusions
describe venous system
capacitance - 61%
more blood since like reservoir
compliant = can change accordingly to changes in vol
describe arterial system
arterial system - resistance - 18%
ensure enough of forces to make blood flow the same
resistance = changes in vol increase resistance
what is stroke volume
70 ml = vol of blood pumped out of heart during each contraction
end diastolic vol - end systolic vol
what is venous return
refers to flow of blood from periphery back to atrium and is equal to cardiac output
what is cardiac output
amount of bloof heart pumps in one min
equal to heart rate x stroke vol
describe flow - series parallel circuit
separates and diff amounts go to diff areas
ex: during exercise vs digestion - increase blood flow of muscles - redistribution of blood flow
always changing
equal vols in and out - 5L
how to calculate flow
flow = v/t
vol/time
mL/min or L/min
cardiac output = 5L/min
normalized = ml/min/100gm
what is flow
blow flow is vol of blood circulating per min of time
expressed in mL/min or L/min
ex of flow calculation = what is the blood flow into the collection bag during a blood donation?
flow = vol/time
flow = 450ml/10min = 45mL/min
if remove too much = faint
describe cross sectional area and flow velocity
flow = area x velocity
(cm^2 x cm/sec or cm^3/sec)
velocity = not necessarily the same at every point in cross section
flow = area x MEAN velocity
increase lumen (area) = increase flow
increase vol = increase flow
when touch walls = greatest resistance near surface, slowest flow
least resistance at center = greatest flow so faster
describe major types of vessels in cvs
resistance vessels = keeps pressure going, big large pressure, large diameter = aorta, arteries, arterioles
capillaries = simple, thin, gas diffusion, efficient system, many since slow things down = for proper perfusion
describe flow – cross sectional area (TOTAL) and flow velocity
increase area = decrease velocity
so proper diffusion
area = have many so combined higher area
what is systole and diastole
diastole = heart ventricle opens
systole = when heart pumps again
describe structure of vessels
helps it work
venules have valves - stop blood from going backwards
30% of blood in systemic circ found in arteries, 5% in capillaries and 65% in veins
what are the advantages of the branching network
cells close to capillary
high total area (cross sectional) of wall of capillaries
low blood flow velocity in capillaries
high cross sectional area
