Lecture 6 - Blood Circuits and the heart Flashcards
How many litres of blood does your heart pump daily?
7000 Litres
With someone who requires cpr, what is the main objective?
The faster you are to getting the heart started, the more likely they are to survive.
4min with stopped heart = death
What happens if your heart stops?
Within 10 second you will pass out (unconscious)
Due to brains reliance of O2 and glucose supplied by blood
have to restart heart within 4min, otherwise death
What is the mortality rate of cardiovascular disease in western society?
1/3 - 1/2
What pumps are involved in the cardiovascular system?
2x pumps
The heart pumps blood into 2 closed circuits with each beat
-systemic(s) circulation (Limbs-musculoskeletal), (Kidneys-renal), (Brain-neural),(Gut+Liver- digestive) (left)
-pulmonary circulation (supplied by right (drain back to left)(lungs)
pumps are stuck together
work simultaneously
What is the role of pumps in the heart?
to push blood out into arteries
(high pressure vessels)
which in turn supply the capillary beds (radiators) with blood (off load + pick up)
drained back to heart by low pressure veins
1x pump supplies
1x receives and passes on too another cicruit
What is the role of capillaries?
off-loading of nutrients and oxygen
pick up waste products and CO2 from cells
What percent of your total blood volume does your heart contain?
7% of blood total
smallest
What percent of your total blood volume does you Pulmonary circuit contain?
9% of blood total
What percent of your total blood volume does your Systemic circuit contain?
84% of blood total
largest
What proportion of the blood in the Systemic circuit is located in your veins?
3/4
What is the role of your veins?
not storage
Ability to hold a RESERVOIR of blood
Can channel blood to other parts of the body as needed
Where does most of the blood in your body sit?
In the veins of your systemic circuit
What is the average amount of blood in your body?
5Litres
What is the output of blood of each pump?
at rest = 5Litres per min
highly variable
exercise = 4x resting rate = 20L per min
athlete = 8x resting rate =40L per min
What are some of the features of the systemic circuit?
Largest circuit- has to reach and supply blood to many organs and systems
High Pressure (driving force)
High Resistance
– harder to push blood around the circuit
involves the LEFT ventricle Receiving OXygenated blood from the lungs and pumps it around the body
What are some of the features of the pulmonary circuit?
Smaller circuit - blood only needs to travel to the lungs
Medium Pressure
Medium Resistance
– effect how the heart LOOKS and FUNCTIONS
involves DE-oxygenates blood being pumped OUT the RIGHT ventricle into the lungs, where it is Oxygenated
What is the role of the lungs?
To Oxygenate blood
Blood drains into the LEFT side of the heart, then pushed (via pressure) out to arteries which supply the systemic capillary network (loses oxygen- pick up waste)
capillary network returns back to systemic veins then to Right side of the Heart
then pumped back to pulmonary circuit
LEFT –> arteries –> systemic capillary –> (drainage) –> systemic veins –> RIGHT –> pulmonary
What type of blood do artery and veins carry?
Systemic ARTERIES: Oxygenated, supplying the capillary beds
Systemic VEINS: DE-oxygenated blood
Pulmonary ARTERIES: DE-oxygenated blood, supplying the capillary beds
Pulmonary VEINS: Oxygenated
Which blood is considered to be blue?
oxygen DEPLETED blood
blue/purplish
from systemic –> pulmonary
What colour is cut blood and why?
Bright Red
When cut the blood very quickly binds with oxygen
Therefore doesn’t mean it always comes from capillaries
How do you define arteries and veins?
Arteries: arteries always take blood AWAY from the pumps
Veins: veins always bring blood BACK to the pumps
What is the exception regarding veins?
Gut absorbs nutrients and transports elsewhere
Gut has a good blood supply
Blood Leaving gut = Deoxygenated
Doesn’t go back directly to the heart, travels via the Hepatic Portal Vein to the Liver/Hepatic
Largest portal vein in the body
Liver has its own blood supply which is receives via Hepatic Arteries
What are Portal veins?
Veins that go from one system to another
neither of those systems being the heart
What is the Filling Phase?
Volume INCREASE (actively-burning energy to occur)(Expanding Chamber)
Venous IN-let on LEFT, FILLING ventricle
Arterial OUT-let on RIGHT, OUTLET-Valve PREVENT BACK-FLOW of arterial blood
inlet valves passively open
What is the Ejection Phase?
Volume DECREASE (Shrinking/Compressing Chamber by the THICK Muscle Walls) INLET-Valve necessary to prevent the HIGH PRESSURE blood form the Pumping chamber from returning Back into the Veins (directional flow required of the blood to eject out of the vein--> artery)
What are the requirements of a Ventricular Pump?
- a Chamber which can Change Volume
- Inlet Valve
- Outlet Valve
(valves steer the blood in the correct direction)
In-effective if it is missing one of these requirements
What is the improvement regarding Increasing the Flow of the pump?
Increase filling rate
narrow opening + inlet valve has to be open
During ejection phase, make Ejection valves closed so blood can pull directly outside the door and when inlet valve opens it can very quickly enter
Atrium, primary job allow blood to pull outside inlet door, so as inlet valve opens a lot of blood can quickly enter the chamber
What is the improvement regarding the walls of the pump?
Pumps is ineffective as only two walls work.
Make outlet the same side as inlet
Now have 3x walls able to Decrease volume and effectively reduce volume of chamber
Increasing efficency
What is the principle role of atriums?
“atriums to buildings”
Primary Role= act as a reservoir
does top up ventricle, doesn’t contribute to main pumping power of the heart
What is the shape of flow of blood in the heart?
V shaped
enters the vein
exits the artery
(makes it efficient)
What is the improvement regarding atrium size?
adding an appendage/ extension of the side of the atrium
“aurical”=(“aur-“=ear)
increases SA and Volume/Capacity of atrium
Why is “ 4x chambered heart” technically incorrect?
Left atrium+ventricle = LEFT pump
Right atrium+ventricle = RIGHT pump
4x chambers, 2x pumps