Blood Circuits and the Heart L6 Flashcards
What is the job of the cardiovascular system?
supports and keeps all the systems running
How many circuits are there in the heart?
2
How many pumps are there in the heart?
2
How many litres of blood are pumped by the heart every day?
7000Litres
What happens if the heart has stopped?
You’ll become Unconscious in 10 sec
Due to the brain being extremely reliant on the oxygen O2 and glucose that is supplied to the brain by the heart
Why do people fall unconscious?
Due to the limited blood supply to the brain
the brain has a massive reliance on the heart due to the O2 oxygen and Glucose that it supplies to the brain
without the oxygen an glucose supply a person faints
Quicker to revive = more likely to survive = decreased degradation of other tissues
What is the brain dependant on from the heart?
Oxygen and glucose
-which is transported in the blood
When has it been to long to revive someone?
4 min
Brain has been deprived of oxygen and glucose from the heart’s blood for too long
has caused Degradation of tissues
Why is it said that the faster you revive someone, the better chance they have of survival?
Because there will be less degradation of tissue
-as shorter amount of time that the tissue hasn’t been deprived of oxygen and glucose(nutrients) - especially the brain -
What are some key features about the systemic arteries?
Taking blood AWAY form the heart
Large circuit, therefore High Resistance, therefore High Pressure
Oxygenated blood
Why is the systemic circuit’s arteries of high pressure?
The systemic circuit is larger
Therefore the circuit has Larger resistance (as blood vessel length and resistance has a directly proportional positive relationship - as blood vessel length increases, so does the resistance of the vessel)
Therefore there is a larger Driving Pressure (as pressure and resistance have a positive relationship)
What are some key features of the systemic veins?
coming BACK TOO the heart
Low pressure (due to pressure gradient-lower/end of systemic circuit)
DEO blood
What are some key features of pulmonary arteries?
DEO blood - as is going too the lungs in order too get oxygenated
AWAY from the heart
Relatively smaller circuit = Medium resistance = medium pressure
What are some key features of the pulmonary veins?
Oxygenated blood - as has just left the lungs which is where oxygenation occurs
Low Pressure (due to being end of the pulmonary circuit pressure gradient)
BACK TOO the brain
Which circuit is the Left pump for?
Systemic circuit
Which circuit is the Right pump for?
Pulmonary circuit
Which capillary beds does the pulmonary circuit go to?
Lungs
site of oxygenation
Which 5x capillary beds does the systemic circuit go to?
- Limbs (musculoskeletal)
- Kidney (renal)
- Brain (nervous)
- Liver (hepatic/endocrine/digestive) repro
- Gut (digestive)
What is the functions of a capillary?
Site of Exchange
the good things (oxygen and nutrients) are picked up
the bad things (CO2 and waste products) are released
Where is the site of exchange?
Capillaries
What is a special and distinguishing feature of the Left systemic circuit?
Portal blood system
Between the 2x capillary beds of the Gut and Liver
called the Hepatic portal vein
Largest portal vein in the body
Gut uses the O2 to supply its cells
Hepatic portal vein carried DEO and nutrient rich blood
travel to liver which is the site of packing, delivering and storing nutrients
This Gut supply is part of the dependant dual blood supply to the liver, of which the liver is reliant on - from both heart and gut wall
What sort of blood flows through the Hepatic portal veins?
DEO
nutrient rich
Why does the nutrient rich DEO blood travel to the liver?
As the liver is the organ for packaging, delivering and storing nutrients
What sort of blood supply does the liver have?
DUAL blood supply
Has Hepatic ARTERIES to get direct blood supply from the heart
Has a Portal Vein to get indirect DEO nutrient rich blood supply (insufficient O2 supply from the gut alone)
Where is there an example of dual blood supply in the body?
Liver
Cannot rely on just the blood from the gut wall along, as there is INSUFFICIENT OXYGEN O2
Therefore has blood supply from BOTH the gut wall and from the heart directly itself
-therefore the liver has (hepatic Arteries as well)
As a dual blood supply, what does the liver also have?
Hepatic ARTERIES (to receive it’s blood supply directly from the heart, just like lots of other organs/capillary beds.
What is a person’s average total BV Blood volume?
5 Litres
can +/- dependant on the weight/size of a person
What is the percentage of total 5L body blood volume in the heart?
7%
What is the percentage of total 5L body blood volume in the pulmonary circuit (veins And arteries) ?
9%
What is the percentage of total 5L body blood volume in the systemic circuit (veins And arteries) ?
84%
What is the difference between blood volume percentages between the pulmonary and systemic circuits?
9x more blood in the systemic circuit than the pulmonary circuit
Where is the greatest proportion of blood in the 84% of total blood volume in the systemic circuit?
3/4 of the blood in the systemic circuit is found in the systemic VEINS
the systemic veins act as a RESERVOIR (not a storage as the blood doesn’t stop) of blood
Reservoir for When More Blood Is Needed
Where is the greatest reservoir of blood in the body?
Systemic VEINS
What is the rate of Cardiac output?
5L per min-1
-pumps the entirety of total blood volume every minute
Why is there a need for a “reservoir” of blood in the systemic Veins?
for when more blood is needed quickly
Why is the 3.4 of 84% total blood located in the systemic Veins a Reservoir and not a storage?
As the blood is STILL MOVING and is just proportionately largely present there so it is AVAILBLE WHEN NEEDED
“Storage” implies that the blood “isn’t moving” -which It is - therefore incorrect
What is a Portal Vein?
A VEIN which goes from 1x system/capillary bed to another system/capillary bed, but when Nether of those systems is the heart
What does “pulmonary” mean?
lungs
What does “hepatic” mean?
Liver
What does “renal” mean?
kidneys
What does “systemic circuit” mean?
circuit of the systems
Which pump has a harder job?
The LEFT pump has a harder job than the right pump as it is responsible for pumping blood Out into a LARGER circuit (of the systems)
What is Heart rate at Rest?
60-70 bpm
What is heart rate when exercising?
4x Resting heart rate
= exercising = 4 x 60/70 = 240/280 bpm
increased rate = increased blood Supply in order to match tissue demand, to keep the muscle tissue going and oxygenated
What is the heart rate of an athlete?
8x Resting heart rate
= athlete = 8x 60/70 = 480/560 bpm
increased rate = increased blood Supply in order to match tissue demand, to keep the muscle tissue going and oxygenated
How many times faster than resting heart rate of 60/70 bpm is a person heart rate approximately when exercising?
4x
= exercising = 4 x 60/70 = 240/280 bpm
increased rate = increased blood Supply in order to match tissue demand, to keep the muscle tissue going and oxygenated
How many times faster than resting heart rate of 60/70 bpm is a person heart rate approximately when you’re an Athlete?
8x
= athlete = 8x 60/70 = 480/560 bpm
increased rate = increased blood Supply in order to match tissue demand, to keep the muscle tissue going and oxygenated
Why is there increased heart rate when you’re exercising or you’re an athlete?
increased rate = increased blood supply in order to match tissue demand, to keep the muscle tissue going and oxygenated
What is required by the systemic circuit (systemic arteries in particular) since it is bigger circuit?
Relationship between vessel length and resistance
since the system circuit is larger/longer, increased resistance, therefore needs greater pressure as a greater driving force through the circuit
What is the heart’s role?
to constantly transport O2 oxygen around the body
What is the approximate length of capillaries in our body?
100,000 km
what percentage of our population dies of CVD disease especially in Western Society?
1/3
No overrides death rates due to cancer
Which circuit return with CO2 and waste?
Only Systemic circuit
CO2 and waste comes from the body systems
-lungs/pulmonary don’t have this waste
What is the definition of an artery?
something (blood vessel) that takes blood AWAY from the heart
- Systemic arteries = Oxygenated
- Pulmonary arteries =DEO
What is the definition of a vein?
something (blood vessel) that take blood BACK TOWARDS to the heart
- Systemic veins = DEO
- Pulmonary veins = Oxygenated (just come form the lungs and has supplied oxygen to the Heart)
What happens when there is a Cut in the arm?
It is unlikely to cut you lungs which is the place of DEO –getting converted into –> ) blood
Cut arm = cut vessels
Red blood =high likelihood that it is an artery
Bleeds= if blood is blue/purple it will still appear red as blood reacts with oxygen in the air when exposed and turns red
What colour should DEOygenated blood be?
blue/purplish
What colour should Oxygenated blood be?
red
What side are the Vena Cavas on?
Right
What is a landmark that Is always on the right side of the heart?
Vena Cavas
What ever side the vena cave’s are on, orientate the picture by knowing that that is the Right side with the Vena Cavas
What landmark does the Pulmonary trunk play in a human heart?
most Anterior/Ventral vessel in a human
What is the most Anterior vessel in a Human heart?
Pulmonary trunk
What is the name of the landmark which separates the ventricles in a human?
anterior/posterior - as is a human - Interventricular sulcus - if on the surface and talking about the fold
anterior/posterior interventricular septum - if talking about inner muscles
How do you expose the anterior view of a human’s heart?
cutting through the sternum
“cracking the chest”
- Bone heals very quickly, and is highly vascular
Where does the Pulmonary artery begin?
Where the Pulmonary Trunk divides
What make up the greatest proportion of the heart?
the ventricles
From what view can you see the pulmonary trunk in humans?
anterior/Ventral view
What is an important and often neglected by students physical structure comparison between the Right Atrium and Auricle?
Different Linings
the auricle is from a different Embryological origin
Why is there a difference between the atrium and auricle?
The auricle is from a different embryological origin
What does the Left pump consist of?
Left atrium and Left ventricle
What does the right pump consist of?
Right atrium and right ventricle
What 3x things are required in order for a pump to be effective?
- a chamber which can change volume (moveable muscle walls)
- an inlet valve (for unidirectional flow)
- an outlet valve (for unidirectional flow)
Why are inlet and outlet valve two of the essential requirements for making an effective pump?
As the inlet and outlet valves ensure Uni-directional Blood flow
What ensures Uni-directional blood flow?
Valve (both inlet and outlet- just at their respective filling and ejection phases)
Which valve is most essential in the filling phase?
Arterial Outlet valve
Closed
In which phase is the Arterial outlet valve most essential?
filling phase
when the outlet valve is closed
Which valve is most essential in the ejection phase?
Venous Inlet Valve
Closed
In which phase is the Venous inlet valve most essential?
Ejection
it is closed, and allows for pulling of the blood in the atria, so when the valve opens blood can open easily
In what phase does the volume of the ventricle increase and the pressure inside the ventricle decrease?
volume and pressure have an inverse relationship (pressure driven my muscular wall action)
ventricular FILLING
Pressure decrease due to muscle walls RELAXING and expanding outwards therefore also increasing volume
In what phase does the volume of the ventricle decrease and the pressure inside the ventricle increase?
volume and pressure have an inverse relationship
Ventricular EJECTION
Pressure increases due to the muscular walls CONTRACTING and moving inwards, therefore also decreasing volume
What are the key features of the Filling phase?
- Outlet valves are essential (to be closed)
- Relaxation/Stretching of the muscular walls Outwards
- involves a Increase in vent. Volume and a decrease in vent. Pressure
- Venous inlet on let and arterial outlet on right
- Arterial outlet is essential - in order to Prevent arterial blood backflow from returning to the pump
- muscular walls stretching/relaxing outwards = increase vol, decrease pressure = - Overall this increase vol and decrease pressu. makes it EASIER for the blood to move in/FILL the ventricle
- as the blood Fills into LOW pressure
- harder as filling relies on the pressure of the veins to fill, and venous pressure is usually Low, therefore the heart needs its 3x modifications in order to fill more effectively
What is the Arterial outlet valve being closed in the Filling phase essential?
the closed Arterial outlet valve being closed during Vent filling, Prevent arterial blood backflow (from returning back into the pump)
What are the key features of the Ejection phase?
- Inlet valves are essential (closed)
- Contraction of the muscular walls Inwards
- involved a volume decrease an a Pressure increase in the ventricle
- Venous Inlet valve being close is essential - as this prevents HIGH pressure blood from returning back into the vein
- muscular walls are contracting inwards = decrease in vol, increase in press(driven by muscular contraction) - This increase in pressure acts as the Driving force which can Pump the blood around the circuit to Overcome the resistance
- Outlet flaps are now just pushed against the arterial walls
- Blood pulls against the closed inlet valves in the atria, therefore blood flows in easily when the inlet valves open
- Blood is ejected out from High pressure
- ejection is easy as it under high pressure, so the blood is just squeezed out, especially with a strong driving force generated by the strong muscular walls of the heart
What wants to be prevented during ventricular ejection?
The high pressure blood going backwards into the vein
Unidirectional flow is wanted therefore it is essential venous inlet valves are closed
What does blood fill into?
Low pressure
What is blood ejected out from?
High Pressure
What is easier: filling or ejection?
Ejection: as ejection is emptied under High pressure, so the blood is squeezed out, and is even easier with strong muscular walls, which the heart has, which allows for a good generation of force
Filling harder: as it relies on the (decent) pressure of the veins to fill, but venous pressure is normally low, therefore it needs modifications to fill
Why does the heart need modifications?
Due to the difficulty in filling
In filling the heart relies on the pressure of the veins
But venous pressure is normally Low
therefore the heart needs modifications in order for the heart to fill more effectively
How do you determine how effective a pump is?
How quickly it fills and how quickly you can empty it
-Note: modification to the filling phase helps instead of just having difficult low pressure of the veins
What does the rate of filling and ejection resemble?
The effectiveness of the pump
What are the 3x improvements to the heart’s ventricular pump?
- having an ATRIUM (receiving/welcoming area)
an atrium on one side acts as a RESERVOIR Upstream of the ventricular pump
Allows the pulling of blood (accumulation of venous blood) during the Ejection phase. This blood can Enter the ventricle Quickly during the filling phase. + if the hole is bigger, then more blood can pool and flood in(auricle) - characteristic V shaped flow of blood in the heart - valves closer together. Inlet and Outlet valve are moved to the same side of the heart. close together. This allows for 3x ventricle walls (more than 2x) to be able to contract. This means that the ventricle now contracts/shortens in Length AND Width during ejection/when they contract. This reduced the Ventricular volume to a greater extent/more pressure generated = can Squeeze blood out more
- AURICLE = dog ear. Add an appendage (auricle)/ Extension on the side of the Atrium, to Increase the Filling capacity/volume of the atria
-Bigger filling area, therefore when venous inlet valves, more blood can quickly flow into the ventricle
(outflow is not a problem due to the strength of the ventricular chamber(high generation o pressure, greater driving force fast and efficient ejection (vs filling will venous low pressure))
What does “atria” mean?
Welcoming/receiving chamber
-acts as a reservoir upstream
allows pooling of blood during ejection phase
-can empty into ventricle easily and fast in filling therefore
(also the bigger the hole, the more blood will pull and fill)
What is a welcoming/receiving chamber?
atrium
-acts as a Upstream Reservoir for blood
allows pulling of blood during the Ejection phase
Therefore this blood can empty into the ventricle easier and faster during the filling phase when the venous inlet valves open
-note: also if the hole is larger, then more blood can pull and more fill under filling
What is the first improvement to the ventricular pump?
having an ATRIUM (receiving/welcoming area)
an atrium act as a RESERVOIR Upstream of the ventricle
Atrium allows blood to Pull during the Ejection phase, there is an accumulation of Venous blood
Then this venous blood which has pulled can enter and fill the ventricle quickly during the filling phase
-larder the hole = more blood can fill = easier and faster filling into ventricle when the venous inlet valves open
What is an improvement onto the first improvement of the ventricular pup?
Increase the size of the hole of the venous inlet, therefore more blood can pull during the ejection phase, and therefore greater quantity of blood filling the ventricle at once (which has already pulled) during the filling phase
What is the second improvement to the ventricular pump?
V shaped flow - valves closer together
-by moving the venous inlet and the atrial outlet valves to the SAME side (CLOSER TOGETHER), this allows for now 3x walls of the ventricle (not just 2x walls) to contract both Width and Length ways
This allows for a Greater Reduction in ventricular volume, as there is More pressure driving for generated by more effective muscular walls contracting/pumping
=Can SQUEEZE MORE blood out
Why is outflow not a problem?
Outflow is not a problem due to the Strength of the chamber(good muscular walls)
=great generation of pressure
=high driving force out
=fast an efficient ejection
What is the third improvement to the ventricular pump?
AURICLE (aur = dog ear)
Add an appendage (auricle)/Extension onto the side of the atrium
This increases the capacity of the atrium
=bigger receiving area
= when inlet valves open, more blood can quickly flow into the ventricle
-(note outflow is not a problem due to the strength of the chamber/muscular walls an their ability to generate the high pressure for efficient and fast driving force of ejection)
What does “aur” in auricle mean?
dog ear
How many pumps and vessels does the heart have?
2x pumps stuck together 2x vessels (aorta and pulmonary artery/trunks) Twist around each other as they exit the heart
Which part of the heart twists around each other?
2x vessels of the Aorta an Pulmonary Trunk/Arteries twist around each other as they Exit the Tank
What chamber is an efficient pump?
Ventricle is = has both inlet and outlet valves-ensuring unidirectional flow. Moving thick walls of a chamber to allows for pressure generation. = fast rate of ejection and filling
-Main pumping chamber. is the Bulk of the heart and is in control of Bulk transport of blood in the heart.
Atria Isn’t: No inlet valve (therefore cant ensure unidirectional flow) and Thin walled, therefore low driving force/generation of pressure = Non-efficient pump = Slow rate of Filling
Why isn’t the Atria an efficient pump?
No inlet valve (therefore cant ensure unidirectional flow)
Thin walled - therefore low driving force generation of pressure
Non-efficient pump = slow rate of filling
How does blood enter the Pulmonary circuit?
Blood drained from the rest of the body
-Therefore Vertical vena cava, allows blood to be drained from the upper (superior) and lower (inferior) parts of the body respective to the vena cava
Blood enters the Right atrium, via the superior and inferior vena cavas
What is the orientation of the drainage of blood into the right atrium?
Right atrium = beginning of the Pulmonary circuit
Therefore blood is draining for the Systemic circuit
Therefore draining form the upper and lower parts of the entire body
Therefore Vertical orientation of the Inferior and Superior and Inferior vena cave to drain the upper and lower parts of the body respectively
How is blood pumped out of the pulmonary circuit?
out through the pulmonary arteries via the pulmonary trunk
Into the pulmonary arteries
Into the Lungs
How does blood enter the systemic circuit?
From the lungs into the systemic circuit
Which are parallel to the sides of the heart
Therefore the blood drains in form the right and left side of the heart
Therefore the systemic circuit entry into the Left Ventricle has a Horizontal orientation/Configuration, as blood drains from either side
What is the orientation of the drainage of blood into the left atrium?
Left atrium= beginning of the Systemic circuit
Therefore the blood is draining from the Pulmonary Circuit (freshly oxygenated blood from the lungs)
Therefore draining from the lungs
Lungs are located on either side (left and right) Parallel o the heart
Therefore orientation of the Pulmonary veins is Horizontal to drain from the left and right lung respectively
How is blood pumped out of the systemic circuit?
out of the Aorta/Systemic arteries/branches of the aorta
Out to the rest of the body systems (circuit of the systems)
What are the 4x peak pressures of the 4x different chambers of the heart?
LA: 8 mmHg
LV: 120 mmHg
RA: 5 mmHg
RV: 27 mmHg
What is the Peak pressure of the RA?
5 mmHg
What is the Peak pressure of the RV?
27 mmHg
What is the Peak pressure of the LA?
8 mmHg
What is the Peak pressure of the LV?
120mmHg
What is 120 mmHg the peak pressure of?
LV
What is 27 mmHg the peak pressure of?
RV
What is 8 mmHg the peak pressure of?
LA
What is 5 mmHg the peak pressure of?
RA
What is the orientation and drainage of the Superior Vena Cava?
vertical
draining the Upper limbs
What is the orientation and drainage of the Inferior Vena Cava?
vertical
draining the Lower limbs
What is the 4x chamber view?
Anterior frontal view
What is another name for the Anterior Frontal view?
4x chambered view
What sort of pressure is the RA receiving?
High pressure from the Systemic circuit (pressure is Lost)
What is receiving the high pressure from the Systemic circuit?
RA
More of the initial pressure is lost as it is a larger circuit
What sort of pressure is the LA receiving?
slightly smaller difference in pressure drop (27-8) as more pressure is retained as a smaller circuit
Which atrium shows more pressure being retained?
LA
pressure drops proportionately smaller (LV –> Ra = 27mmHg –> 8mmHg)
more pressure is retained as it is a smaller circuit
Which atrium shows less pressure being retained?
RA
pressure drops proportionately larger (RV –> LA = 120mmHg –> 5mmHg0
Less pressure is retained as it is a larger circuit
Why is there a difference between the 2x atriums?
the RA has a bigger pressure drop (120 —>5 mmHg) as is has a Bigger circuit therefore LESS pressure is RETAINED
the LA has a smaller pressure drop(27mmHg –> 8mmHg) as it is a Smaller circuit and therefore MORE pressure is RETAINED
Which atrium has a greater pressure and why?
LA
as it has come from a SMALLER pulmonary circuit where MORE pressure has been RETAINED
Which atrium has a smaller pressure and why?
RA
as it has come from a LARGER systemic circuit where LESS pressure has been RETAINED
What do valves open and close in response to?
Pressure changes
as the heart contracts and relaxes
What do valves mediate?
Unidirectional flow of blood
- avoid back flow
- allows pulling of blood
What does the unidirectional/one-way flow of blood allow and avoid?
Allows the Pulling of venous blood in the atria against the closed inlet valves (due to pressure difference)
Avoids the backflow of blood back into the veins
What mediates the unidirectional flow of blood?
Valves
What is the placement of valves in relation to one another?
One the same side
Allows for V shaped flow
Allows contraction of 3x walls of the chamber, therefore greater generation of pressure/force to move blood, therefore more blood squeezed out
What opens the Passive valve leaflets?
During CONTRACTION, the blood flows from High pressure —> to Low pressure
There is a decrease in volume
Moving the passive valve flaps to be pushed against the walls of the valve
What is the job the atrium if it is an Insufficient pump?
to TOP UP the ventricle with the LAST 20% of blood as is a RECEIVING RESERVOIR for blood
Why is the function of the atrium being a receiving reservoir of blood beneficial?
Allows the atrium to TOP UP the ventricle with the last 20% of blood
Which chambers can you survive without?
Your atriums
as the Ventricles are the main pumping chambers of the heart
You can survive with only you ventricles (and non-functioning atriums) perfectly fine
What is another disappointing physical structure of the atria as an insufficient pump?
Majority of SMOOTH muscle
Ventricle has more skeletal muscle
Does the atrium and auricle have the same physical texture?
NO
Auricle has trabeculae
Atria doesnt
What sort of flaps are atrioventricular valves?
Passive structures
Burn no energy in their movement
Are just moved by activities occurring at the same time in their surroundings (i.e. the movement of blood and pressure generated (downward direction of pressure gradients))
Are Valve flaps Passive or active structures?
Passive structures
Burn no energy in their movement
Are just moved by activities occurring at the same time in their surroundings (i.e moved according to the movement of blood and pressure generated(downward direction of pressure gradients))
Are Both Atrioventricular and Semilunar valve flaps Passive structures or are only Semilunar flaps passive?
BOTH are passive valve flaps
What is the collective name for inlet valves?
Atrioventricular valves
-as they form the boundary between the atrium and the Ventriule
What is the collective name for outlet valves?
semilunar valves
-named according to the artery they feed into
What is the name of the Left Inlet Atrioventricular valve?
Bicuspid
Mitral
2x valve flaps
What is the name of the Right Inlet Atrioventricular Valve?
Tricuspid
3x valve flaps
What are Valve flaps made of?
Endocardium
Have a Connective tissue core of collagen
What structure in the heat is passive, Made of Endocardium, and has a Connective Tissue core of collagen?
Valve flaps
What is the connective tissue core of valve flaps made out of?
collagen
What is the role of Chordae Tendineae?
Only located on inlet Atrioventricular Valve flaps
Tethered to the Free edges of each flap
Prevents the inlet valve fro bursting upwards totally into the atrium during Systole
Only really function during Systole (ventricular ejection where it is essential that the inlet valves are closed- allows for the pulling of venous blood and prevents back flow of high pressure ventricular blood back into the veins)
Allows for sufficient Tension to be generated
What is the role of the Papillary muscle?
Nipples of the heart/ventricular wall
Functions only during Systole/ventricular contraction
Have the chordae tendineae attached, together allow for sufficient tethering and tension to be produced, to close/seal the free edges of the inlet atrioventricular valves closed.
Why is there a structural difference between the AV and SL valves and as well as with their presence/absence of supportive tension generating structures?
INLET holes are LARGER, as it needs to be EASIER for blood to FLOW IN under LOW PRESSURE
therefore the bigger valve, requires Bigger Flaps to Close and therefore requires Something to Restrain the flaps and ensure their effectivity (Chordae Tendineae and Papillary muscles)
Are inlet holes larger than outlet?
Yes
Inlet valve > Outlet valve
INLET holes are LARGER,
Due to the need for it to be EASIER for blood to FLOW IN under LOW PRESSURE
therefore the bigger valve, requires Bigger Flaps to Close and therefore requires Something to Restrain the flaps and ensure their effectivity (Chordae Tendineae and Papillary muscles)
Are outlet holes larger then inlet?
No
Outlet are smaller than
What makes up the core of the heart?
Left Ventricles
What is the shape of the LV?
donut/cone shaped
Hollow cone
Thick Muscular walls
What is the shape of the RV?
Hip Pocket
on the side of the LV
Are the inlet valves high or low pressure?
Larger inlet
Low pressure - easy flow of blood in (filling into low pressure)
Are the outlet valves high or low pressure?
Smaller Outlet valves
High pressure - generates by the thick ventricular walls to drive blood out through either the pulmonary or systemic circuit
What ensures the efficient operation of pumps?
Valves
What is the pathway of blood?
Approximately V shaped
What is the ratio of peak pressures between ventricules?
LV: RV
120mmHg : 27 mmHg
5:1
What is the ratio of wall thickness between ventricles?
LV:RV
10-15mm : 5mm
3:1
Combining the ratios of wall thickness and peak pressures of ventricles , what is a important thought to consider?
LV is 3x the thickness
and is able to generate 5x the pressure
What does Low pressure in the atria allow for?
Greater filling - as is quicker down (larger) gradient at a low pressure, and has a LARGER valve size (inlet>outlet size opening/hole/valve)
What is the state of your heart when you are born?
Same size LV and RV
Blood is pumping around the same circuit - Due to being connected to your mother (dependant on mother)
When separated from mother, must now breath and digest alone, (independant) therefore the 2x Circuits SEPARATE
as you grow the Systemic circuit grow much faster than the pulmonary circuit
Therefore the wall thickness of the Left ventricle must grow thicker and stronger in response to this in order to remain efficent
Which valve flaps do not have chordae tendineae?
Outlet valve/Semilunary/3D pocket shaped flaps
How many valve pockets does the Aortic Outlet valve have?
3x pockets
-same as pulmonary
How many valve pockets does the Pulmonary Outlet valve have?
3x pockets
-same as aortic
Why are outlet valves called semilunar valves?
are pockets
take strength form their 3D shape
Look semi moonlike
What are closely associated with SL valves and when do they fill?
Coronary arteries
-one runs down the inter ventricular septum
Fill during ventricular filling - diastole (blood pulls against outlet valves trying to get back into low pressure ventricle and fills the coronary ostias)
What is the name of the entry into the coronary arteries and when do they fill?
coronary ostia
During diastole - Outlet valves are Essential at being closed, therefore holes arent covered and blood can enter and fill the coronary ostias
Are SL valves smaller or larger than AV valves?
Smaller
Smaller outlet hole (due to high pressure driving force needed to drive blood out)
Get strength from their 3D strucutre
What does it mean when a structure is called “Passive”?
Doesn’t burn any energy in its movement
Is moved as a result of events that are occurring at the same time around it
What is the name of the Right outlet valve?
Pulmonary Semilunar valve
-named after the structure it is pumping into
(pulmonary trunk/arteries)
What is the name of the Left outlet valve?
Aortic Semilunar valve
-names after the structure it is pumping into
(aorta/aortic arteries)
What occurs during Ventricular Filling re outlet valves?
Outlet valves are closed
Pressure is High OUTSIDE of the ventricle
Aorta>Ventricle
The pressure of the blood trying to re-enter the Ventricle forces the Free edges of the Cusps tightly together
As the outlet valves fill, the superior lips are pressed together against the neighbouring valve leaflets
-fills and therefore closes pocket
What occurs during Ventricular Ejection re outlet valves?
Outlet valves are open
Pressure is High INSIDE the ventricle
ventricle > aorta
The pressure results in the flow of blood Out of the ventricle (down pressure gradient)
-The passive flaps are pushed against the ventricle wall, as the blood is ejected out via High Pressure
Ventricle Contract
What 2x things does the Semilunar valves allow for?
- Ejection of blood from the heart –> arteries
2. Prevention of the backflow of blood back into the ventricles
Why doesn’t the Semilunar valves have chordae tendineae?
Difference in structure- strength comes from shape of full 3D cups rather than tension from cords
+ the chords would Impede flow and be NEgative rather than positive for outlet valves- and their efficiency
Is it okay if some of the valve flaps (especially on older people’s semilunar valve flaps) have some lumps in it?
Yes it is fine to have a few lumps
Just as long as the cusp’s free edges still seal together
