Cardiovascular System Flashcards
What is the journey of blood through the heart (starting with the left side)
- Left pulmonary vein
- Left atrium
- Bicuspid valve
- Left ventricle
- Aorta
- The rest of the body
- Vena Cava
- Right atrium
- Tricuspid valve
- Right ventricle
- Right pulmonary artery
What is the pulmonary circuit ?
The circuit that carries deoxygenated blood to the lungs and oxygenated blood back to the heart.
The right side of the heart
What is the systemic circuit ?
Carries oxygenated blood to the rest of the body and deoxygenated blood back to the heart.
The left side of the heart.
What is the conduction system ?
A set of 5 structures which pass electrical impulses through cardiac muscles.
What is the first step of the conduction system ?
The sino-atrial node is located in the right Atrium walls.
This generates an electrical impulse which is passed through the muscular walls causing them to contract.
The sino-atrial node is referred to as the ‘pace-maker’ of the heart.
What is step 2 of the conduction system ?
Atrio ventricular node collects the impulse and delays it by 0.01s
This allows the atria to finish contracting.
Then the impulse is released to the HIS bundle.
What is step 3 of the conduction system ?
The HIS bundle is located in the septum.
It splits the impulse into two ready to be distributed into each ventricle.
What is step 4 in the conduction system ?
The bundle branches carry the impulse to the bottom of each ventricle.
What is step 5 on the conduction system ?
The Purkinje fibres distribute the impulse to the ventricle walls which makes them contract.
What is oxygenated blood ?
A blood cell that has a high proportion of oxygen and a low proportion of carbon dioxide.
What is deoxygenated blood ?
A blood cell that has a low proportion of oxygen and a high amount of carbon dioxide.
What does it mean if the cardiac cycle is myogenic ?
The heart initiates its own muscle contractions automatically.
What is cardiac output ?
The quantity of blood pumped by the heart in one minute.
What is a heart rate ?
The number of times a heart beats per minute.
What is the stroke volume ?
The volume of blood pumped by the left ventricle in one beat.
What does systole mean ?
The contraction of the cardiac muscle.
What is diastole ?
The phase of the heartbeat when the heart muscle relaxes.
What is the septum ?
It is the partition between the right side and the left side of the heart to ensure that the oxygenated and deoxygenated blood doesn’t mix.
What is the aorta ?
Takes blood away from the left side of the heart and pumps the blood towards the rest of the body hence why it is the biggest artery in the body.
What is the vena cava ?
Allows deoxygenated blood into the heart from the body
Where are the atriums in the heart ?
They are the top two chambers, one on the left and one on the right
What are the ventricles ?
Ventricles are the bottom two chambers of the heart with a left and right ventricle.
Where is the tricuspid valve ?
it is on the right hand side of the heart.
In between the right atrium and the right ventricle
What is the bicuspid valve ?
It is on the left side of the hard.
It is in between the left atrium and the left ventricle.
What is the right pulmonary artery used for ?
It takes the blood out of the right side of the heart and takes the blood to the lungs.
What is the left pulmonary vein used for ?
It brings the oxygenated blood from the lungs back to the heart.
What happens during atrial diastole ?
As the atria and ventricles relax, they expand which draws blood into the atria.
The pressure in the atria increases opening the AV (bicuspid and tricuspid)
Blood then enter the atria.
Semi-lunar valves are closed to prevent blood from leaving the heart.
What happens during atrial systole ?
The atria contacts forcing the blood into the ventricles
What is ventricular systole ?
The ventricles contract which increases the pressure.
This closes the AV valves to prevent any backflow into the atria.
Semi-lunar valves are forced open as blood is * from the ventricles into the aorta and into the pulmonary circuit.
What is the average resting heart rate ?
72bpm
What are the factors that can affect resting heart rate ?
- Genetics
- Gender
- Fitness
What is the term if someones resting heart rate is below 60bpm ?
Bradycardia
What is the equation for cardiac output ?
Cardiac output = stroke volume x heart rate
What is a maximal effort in sport ?
- high intensity
- anaerobic exercise
- pushes a performer to their maximum
What is a sub-maximal effort in sport ?
- low/moderate intensity
- aerobic exercise
What is the anaerobic hr zone ?
85% - 100%
What is the aerobic Hr zone ?
60% - 85%
What is the HR response to exercise at sub-maximal effort ?
- rapid increase in HR once exercise has begun
- HR plateaus before an initial rapid decrease once exercise has stopped
What is HR response to exercise at maximal effort ?
- Rise in hr due to adrenaline before exercise (anticipatory rise)
- No plateau due to intensity is always increasing
- Hr constantly rising until exhaustion where it drops
What is hypertrophy ?
Enlarged cardiac muscle as a result of exercise
What is cardiovascular drift ?
- Although after 20 minutes of exercise you are working at the same effort your heart rate continues to rise
- This is due to cardiovascular drift
- This happens because during exercise you sweat and lose plasma from your blood as plasma is like water
- This makes the blood thicker which makes it harder for the body to pump around
-Therefore the heart is having to work harder so Hr is raised - However stroke volume is decreased because the blood is so thick it is more challenging to pump it around the body as well.
What is venous return ?
- The amount of blood that returns to the heart through the veins and venules against gravity.
- At rest, blood pressure and veins will maintain venous return but it cannot cope alone during exercise, where the demand for o2 and blood flow increases.
- This means we must utilise the 5 venous return mechanisms
What is Starlings law ?
- How stroke volume is dependent on venous return
- Stroke volume = venous return
- With more blood returning to the heart during exercise, the left ventricle walls stretch and eject a larger volume of blood per beat
What are structural features of arteries ?
- They have a large layer of smooth muscle and elastic tissue
- small lumen
- high pressure
What are the functions of arteries ?
- transport blood away from the heart
- the smooth muscle allows for vasodilation and vasoconstriction
What are the structural features of veins ?
- valves which prevent backflow
- large lumen
- low pressure
What are the functions of the veins ?
- transports deoxygenated blood from the muscles and organs back to the heart
What are the structural features of capillaries ?
- thin
- 1 cell thick
What are the functions of capillaries ?
- help with gaseous exchange and diffusion
- also helps with waste exchange
- allows a higher diffusion rate as there is larger surface area
What is the pocket valve mechanism ?
One way valves located in the veins which prevent backflow of the blood
What is the smooth muscle mechanism ?
The layer of smooth muscle in the vein wall vasocontricts to aid the movement of blood
What is the gravity mechanism for venous return ?
Blood form the upper body, above the heart is assisted by gravity to return back to the heart
What is the skeletal muscle pump for the venous return ?
During exercise, skeletal muscles contract, compressing veins located between them. This forces blood back to the heart.
What is the respiratory muscle pump and how is it effected during exercise ?
During respiration and expiration, a pressure difference between the thoracic and abdominal cavity is created
This squeezes the veins which pushes blood back to the heart.
Increased breathing rate causes an increased effect, returning more blood to the heart.
What are the vascular walls ?
The dense network of blood vessels and the blood which they carry.
What does blood consist of and what are the function ?
Blood consists of 45% cells and 55% plasma which functions
- transport of nutrients
- protect and effect disease
- regulate body temperature
What is blood pooling ?
- Where blood sits in pocket valves and accumulate
- This happens if we stop exercising suddenly
- To prevent blood cooling and help venous return we should do an active cool down
What is the vascular shunt mechanism ?
- The redistribution of blood from one area of the body to another.
Where do arterioles lead to ?
They lead to capillary beds which allow for gas exchange when in close contact with organ and muscle cells
What is vasodilation ?
The arterioles dilate which allows maximum blood flow through capillary beds
What is vasoconstriction ?
They constrict which limits blood flow through capillary beds.
What are pre-capillary sphincters ?
Rings of smooth muscle that can contract and dilate which controls blood flow through the capillary beds
What happens when the sphincters vasodilate ?
- More blood travels through the capillary bed at one time.
- This increases surface area for surface area for gaseous exchange
What controls the vascular shunt mechanism ?
Vasomotor control centre
Where is the VCC located ?
Medula Oblongata
What state are the smooth muscles in the walls of arterial blood vessels in ?
Contractions
Is oxygen or carbon dioxide more acidic ?
Carbon dioxide
What do chemoreceptors detect during exercise ?
- chemical
- detect an increase in CO2 and lactic acid levels
What does CCC stand for ?
- Cardiac Control Centre
Where are barorecepters found ?
In the artery walls
Where are chemoreceptors found ?
In the aortic bridge and the carotid artery
What are proprioceptor ?
They are found in the muscles, joints and tendons
- They inform the CCC of motor activity
What are thermorecepters ?
Detect an increase in blood temperature and inform the CCC.
What does sympathetic mean ?
Increases the heart rate
What does parasympathetic mean ?
A decrease in heart rate
What is the speed of heart rate controlled by ?
The CCC and the sino-atrial node
What are the 3 parts of the neural control system ?
- Chemoreceptors
- proprioceptors
- barorecpeters
What is intrinsic control ?
- temperature changes affect the blood viscosity and slows nerve impulse transmitters
- changes in venous return will affect the stretch in ventricle walls which affect the ventricular contraction and stroke volume
What is hormonal control ?
- adrenaline and noradrenaline are released which increase speed and force contraction which increases stroke volume
- Speed up the speed of electrical activity in the heart which increases Hr.
What speeds up hr (nerves) ?
Accelerator nerve
What slows down hr (nerves) ?
Vaugus nerve
What is the simple definition of blood pressure ?
The force exerted by the blood against the blood vessel wall (artery)
What is the formula for blood pressure ?
blood flow x resistance
What forces blood under high pressure ?
- when a heart contracts
What is the typical reading of blood flow ?
120mmHg/80
What are the units for blood pressure
- mmHg
- mm is millimetres
- Hg is mercury
Where do you take someones blood pressure ?
The brachial artery which is in the upper arm
What does the top and bottom number mean for someones blood pressure ?
The top number is systole ( contraction)
The bottom number is diastole ( relaxation)
What helps assist the disassociation of blood
- temperature increase
- partial pressure co2 becomes higher than o2 pressure
- blood pH drops (more acidic)
What is an anticipatory rise ?
An increase in heart rate prior to exercise due to the release of adrenaline
What is heart disease ?
- Known as coronary heart disease
- Occurs when the coronary blood vessels are blocked by fatty deposits
- This limits the supply of oxygenated blood to the heart
- Known as atherosclerosis
- Lack of oxygen can result in discomfort known as angina
What are the two types of stoke ?
- Ischaemic strokes
- Haemorrhagic stokes
What is a ischaemic stroke ?
Occurs when a blood clot stops the supply of blood from reaching the brain (most common)
What is a haemorrhagic stroke ?
Are the result of a weakened blood vessel which means the brain bursts
What controls the sympathetic nervous system ?
Medulla Oblongata
How can heart disease result in a heart attack ?
- hardening of coronary arteries
- causing blockages
- Less supply of oxygen to the heart
How can exercise decrease the risk of heart disease ?
- Decrease in cholesterol
- Lower blood pressure
- Stronger heart