cardiovascular - lecture 2

Question 1

what is comparative physiology

Answer 1

subdiscipline of physiology that studies and exploits diversity of functional characteristics and various kinds of organisms

Question 2

describe insect circulation gen

Answer 2

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

Question 3

what is hemolymph

Answer 3

circulatory fluid in insects, spiders, crustaceans etc
corresponds to blood and isf in vertebrates

Question 4

describe circulatory system of insects

Answer 4

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)

Question 5

describe heart part of insects

Answer 5

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

Question 6

describe fish circulation

Answer 6

closed circulation
single loop circulation
2 chambers
gil capillaries = exchange o2, o2 rich and depleted o2 blood, sends blood to gils, feeds organs

Question 7

describe circulatory system of fish

Answer 7

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

Question 8

describe amphibian and most reptilians circulatory system

Answer 8

closed circulation
double loop circulation
3 chambers
other loop for o2 exchange
one ventricle = mixed blood
1 loop for organs - periphery

Question 9

describe circulatory system of amphibians

Answer 9

closed
2 circulations = small or pulmonocutaneous circuit and large or systemic circuit
heart = 3 chambers, 2 atria, 1 ventricle

Question 10

what does small circulation do - amphibians

Answer 10

leaves ventricle towards the lungs and skin - places where gas exchange happens

Question 11

describe blood movement - amphibians

Answer 11

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

Question 12

One ventricle – How does that work in terms of oxygen rich vs oxygen depleted blood?

Answer 12

dont get mixed bc structure and pressure of heart = does not need septum
pressure is perfect
not much mixing

Question 13

describe croc/alligator circulation

Answer 13

2 aortas - allow alligator to function underwater
underwater = less oxygenated blood

Question 14

describe croc heart

Answer 14

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

Question 15

describe when underwater - croc/alligator

Answer 15

valve between right ven and pulmonary circ = called gear tooth valve
closed

Question 16

describe blood movement - croc/alligator

Answer 16

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

Question 17

describe avians and mammalian circ

Answer 17

right heart = pulmonary circ
left heart = systemic circ
closed circulation
double loop circ
4 chambers

Question 18

describe avians and mammalian heart

Answer 18

4 chambers = 2 atria and 2 ventricles separated by septum

Question 19

describe avians and mammalian 2 circulations

Answer 19

right side sends blood to lung - pulmonary circ
left side sends blood to rest of body - systemic circ

Question 20

describe avians and mammalian - unlike amphibians and reptiles

Answer 20

oxygenated blood separated from deoxy = allow better supply of o2 to cells and tissues
we warm blooded

Question 21

what are hemodynamics

Answer 21

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

Question 22

what is blood volume

Answer 22

5L (75ml/kg)

Question 23

what is 1 unit of blood

Answer 23

450mL
vol of blood contained in a bag containing a therapeutic dose of blood used for transfusions

Question 24

describe venous system

Answer 24

capacitance - 61%
more blood since like reservoir
compliant = can change accordingly to changes in vol

Question 25

describe arterial system

Answer 25

arterial system - resistance - 18%
ensure enough of forces to make blood flow the same
resistance = changes in vol increase resistance

Question 26

what is stroke volume

Answer 26

70 ml = vol of blood pumped out of heart during each contraction
end diastolic vol - end systolic vol

Question 27

what is venous return

Answer 27

refers to flow of blood from periphery back to atrium and is equal to cardiac output

Question 28

what is cardiac output

Answer 28

amount of bloof heart pumps in one min
equal to heart rate x stroke vol

Question 29

describe flow - series parallel circuit

Answer 29

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

Question 30

how to calculate flow

Answer 30

flow = v/t
vol/time
mL/min or L/min
cardiac output = 5L/min
normalized = ml/min/100gm

Question 31

what is flow

Answer 31

blow flow is vol of blood circulating per min of time
expressed in mL/min or L/min

Question 32

ex of flow calculation = what is the blood flow into the collection bag during a blood donation?

Answer 32

flow = vol/time
flow = 450ml/10min = 45mL/min
if remove too much = faint

Question 33

describe cross sectional area and flow velocity

Answer 33

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

Question 34

describe major types of vessels in cvs

Answer 34

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

Question 35

describe flow – cross sectional area (TOTAL) and flow velocity

Answer 35

increase area = decrease velocity
so proper diffusion
area = have many so combined higher area

Question 36

what is systole and diastole

Answer 36

diastole = heart ventricle opens
systole = when heart pumps again

Question 37

describe structure of vessels

Answer 37

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

Question 38

what are the advantages of the branching network

Answer 38

cells close to capillary
high total area (cross sectional) of wall of capillaries
low blood flow velocity in capillaries
high cross sectional area