1.1 Cardiovascular System Flashcards
Anticipatory rise
Slight increase in heart rate due to expectation of exercise
What is the systole phase
The contraction part of the cardiac cycle
What is the diastole phase
Term used to describe the relaxation phase of the cardiac cycle
What valve leads from the right atrium to the right ventricle
The tricuspid valve
What valve leads from the right ventricle to the pulmonary artery
Pulmonary semilunar valve
What valve leads from the left atrium into the left ventricle
Bicuspid valve
What valve leads from the left ventricle into the aorta
Aortic semilunar valve
What are the tendons in the heart called
Chordae tendinae
What is the direction of blood flow in the heart
Superior Vena Cava,Right atrium,Tricuspid valve,Right Ventricle,Semilunar valve,Pulmonary artery,lungs,pulmonary vein,left atrium,bicuspid valve,left ventricle,Aortic valve,Aorta,Body
Stroke volume
The amount of blood ejected with each cardiac cycle
Cardiac output
The amount of blood pumped by the heart in a given period of time (hrXSV)
Where does the sino atrial node sit
Above the right atrium
Function of the sino atrial node
Myogenic (self regulating) pacemaker and emits a signal out across the atria causing contraction of the atria
Where does the atria ventricular node sit
In between the right atrium and ventricles
What is the function of the atria ventricular node
Recieves signal from SA node and is going to relay the signal to the bundle of his in the septum
Function of the bundle of his
Seperate the signal into left and right branches
What is the signals from the bundle branches sent to
The purkinje fibers that spread the signal to the cardiac muscles
What do the cardiac cells then finally do
Contract upwards
What is the all or none rule
The heart either contracts fully or not at all
What are the short term effects of exercise
Increased HR due to rising adrenaline levels
Increase in stroke volume due to stronger contractions
Increased Cardiac output
What are the Long term effects of Exercise on the cardiovascular system
Decrease in Resting HR
Increase in Resting SV
Hypertrophy of the heart
Thicker left ventricle wall
Increased number of capillaries
Increase in blood volume
Improvement in Cardiac output during exercise
What is a sharp raise in heart rate caused by
Mainly anaerobic work caused by propiocepter/sensory stimulation,continued release of hormones and action of muscle pump
What is a continued high HR caused by
Due to maximal loads continuing to stress anaerobic systems
What does a steady high HR cause
It causes lactic acid
Why does rapid recovery take place
Due to the ending of proprioceptive stimuli/muscle pump/withdrawl of hormones,fast recovery of PC stores
Why does slow recovery happen
Clearance of metabolites (lactic acid),heat loss causes muscle cooling,general body systems returning to pre exercise levels
What is the difference in cardiac output at rest between a trained person and untrained person
The difference is the same
What is the difference in cardiac output between a trained person and untrained person during exercise
The trained person has a higher cardiac output due to a higher stroke volume
What three main mechanisms control the rate at which impulses are fired
Sympathetic nervous system
Parasympathetic nervous system
Medulla oblongata
What is the sympathetic system
A part of the autonomic nervous system that speeds up heart rate
What is the parasympathetic system
A part of the autonomic nervous system that decreases heart rate
What is the parasympathetic system
A part of the autonomic nervous system that decreases heart rate
What is the Medulla Oblongata
The most important part of the brain as it regulates processes that keep us alive such as breathing and heart rate
What is the autonomic nervous system
It determines the rate at which the SA node sends out impulses
What does the parasympathetic nervous system release
Acetycholine
What is the cardiac control system stimulated by
Chemoreceptors,Baroreceptors,Proprioceptors
Where are chemoreceptors found
Carotid arteries,aortic arch
What do chemoreceptors do
They detect an increase in Carbon Dioxide and sense chemical changes
What do baroreceptors do
They respond to changes in blood pressure due to the stretching of the arterial wall
What does an increase in arterial pressure cause
An increase in the stretch of the baroreceptor sensors and results in a decrease in HR
Where are the proprioceptors located
Muscles,tendons and joints
How does the sympathetic nervous system speed up heart rate
Increases HR by releasing adrenaline
Adrenaline increases the strength of ventricular contractions (increases SV)
Noradrenaline aids the spread of electrical impulses through the heart increasing HR
Increased metabolic activity causes an increase in CO2
This increase is detected by chemoreceptors which inform the sympathetic centre to increase HR
What do proprioceptors do
They provide information about movement and body position and detect an increase in muscle movement.In turn a signal is sent to the medulla which then sends a signal to increase HR
Which chamber in the heart are larger explain why?
ventricle, as they pump blood out of the heart to the body
Order impulse from SAN travels
SAN, Atrial systole, AVN, bundle of His, bundle branches, purkinje fibres, ventricular systole
The heart muscle is myogenic, what does this mean?
Has it’s own electrical impulse, so it will therefore keep on beating even with the absence of the brain
avg number of times the heart beats per minute (untrained vs trained) at rest
untrained - 72
trained - 60
SV of untrained vs trained person during excerices
untrained - 120 ml
trained - 170ml
Plasma
the fluid part of your blood (mainly water) that surround blood cells and transport them
haemoglobin
an iron containing pigment found in red blood cells, which combines with oxygen to form oxyhemoglobin
myoglobin
Heme protein found in skeletal and cardiac muscles with the main function being the transfer of oxygen from muscle cell membrane to mitochondria
What is the Bohr Effect
The shift to the right in the Oxyhemoglobin dissociation curve
What causes the Bohr Effect
Increase in CO2 blood levels
Increase in Body Temperature
Increase in Acidity
What is Venous return
The returning of deoxygenated blood to the right side of the heart via the vena cava
What mechanisms carry out Venous return
The skeletal muscle pump
The respiratory pump
Pocket valves
Gravity
Smooth muscle
How does the Bohr Effect help
The Bohr effect leads to less O2 saturation of haemoglobin,In turn O2 has less affinity with the Haemoglobin meaning an increase in oxygen release to the working muscles
How does the skeletal muscle pump work to help venous return
When muscles contract and relax as they change shape.This change in shape means muscles press on the nearby veins and cause a pumping effect and squeeze blood towards the heart
How does the respiratory pump work to help venous return
When muscles contract and relax during breathing in and breathing out,Pressure changes occur in the thoracic and abdominal cavities,The changes in pressure compress veins and assist flow to the heart
How do pocket valves help venous return
The valves prevent the backflow of blood allowing for quicker venous return
How does the layer of smooth muscle in the walls of the veins help venous return
They help squeeze blood back towards the heart
How does gravity help venous return
Gravity helps the blood return to the heart from the upper body
Why are cool downs important after exercise for venous return
Prevents blood pooling by maintaining venous return using the VR mechanisms
What is blood pressure
The force exerted by the blood against the blood vessel wall
What is systolic pressure
The pressure in the arteries when the ventricles are contracting
What is diastolic pressure
The pressure in the arteries when the ventricles are relaxing
What is Venous return
The return of blood to the right side of the heart via the vena cava
What is Starlings law
If more blood is being pumped back to the heart then it means more blood has to be pumped out
What is myoglobin
The molecule in your muscles that transports oxygen from the muscle cell membrane to the mitochondria
What happens during prolonged steady state exercise after at least 10 minutes in a warm enviorment
Stroke volume and arterial pressure progressively decrease
A progressive rise in HR
What happens when cardiovascular drift occurs
Heart rate increases,Stroke volume decreases,Cardiac output slightly increases
How to minimise cardiovascular drift as an athlete
Stay hydrated/stay cool in hot conditions
Maintain high fluid consumption before and after exercise
What is cardiovascular drift
Stroke volume decreasing due to us losing fluid from sweating,this lowers blood plasma,as a result HR increases
What is an Arteriole and what is its function
A very small blood vessel that branches off from your artery and carries blood away from the heart,They also control blood flow and blood pressure
What is A-VO2 difference
The difference between the oxygen content of the arterial blood arriving at the muscles and venous blood leaving the muscles
Why is a trained person’s A-VO2 difference higher than an untrained persons
A trained footballer can extract more oxygen from the blood due to a greater number of capillaries,myoglobin,haemoglobin and enzymes
