Cardiovascular System Flashcards
Name the characteristics of pulmonary circulation
- flow of deoxygenated blood
- goes from heart to lungs where it is oxygenated and then returns back to the heart
Name the characteristics of systemic circulation
- movement of oxygenated blood from the heart to all body tissues
What is the pericardium sac?
A thin layer fibrous sac that helps keep the heart in place
What is the epicardium?
The outer and protective layer of the heart
What is the myocardium ?
The strong muscular middle layer that forms the wall of the heart
What are the functions of the CV system?
- provide body with sufficient O2
- transport nutrients around the body
- remove waste products
- regulate body temperature
What is capillarisation and what are the advantages for athletes?
- new capillaries form
= advantageous for athlete as more capillaries will surround muscle tissue
= more gaseous exchange can occur
= higher rate of performance
What are the functions and structures of erythrocytes (rbc)?
- haemoglobin in RBC’s carry O2 from lungs to muscles (oxyhaemoglobin)
- remove CO2 (forming carbaminohaemoglobin) also CO2 forms in plasma
= back to lungs and heart - have a biconcave disc = maximised SA for gas exchange of O2
What are structures and functions of plasma?
- clear fluid that carries solid cells and platelets
- also carries hormones, nutrients, protiens to parts of the body that need it
- can carry carbaminohaemoglobin (dissolves/ converted into carbon acid)
What are 3 ways CO2 is carried in the blood?
- dissolved in blood plasma
- CO2 is converted into carbonic acid
- binds to haemoglobin
What percentage of our blood is plasma?
55%
What are the structures and functions of leukocytes? (Wbc)
- contain big nucleus
- defend against disease
- consists of lymphocytes and macrophages that engulf and destroy pathogens
- some lymphocytes produce antibodies to destroy invades and produce antitoxins to break down poisons
What are the structure and functions of platelets?
- tiny p;late shapes cytoplasmub bags
- consist of blood clotting chemicals
- stop blood loss through clotting
= sticking to exposed collagen fibres
= and producing tiny fibrinogen fibres that form a net
= stops bleeding
Where are platelets produced?
Bone marrow
What is another name for platelets?
Thrombocytes
What are the 5 functions of the CV system?
- delivering oxygen and nutrients
- removing waste
- thermoregulation
-fighting infection - clotting of blood
Delivering oxygen and nutrients
- during exercise, we need more oxygen and nutrients. The CV system will respond, supplying the body to meet the demands.
- however, when the CB system can no longer meet demands, fatigue will occur, and performance will deteriorate.
Removing waste
- the circulatory system carries waste products from the tissues to the kidneys and the liver and returns carbon dioxide from the tissues to the lungs
- during exercise your muscles will produce more carbon dioxide and lactate and it is essential that these are removes, otherwise muscle fatigue will occur.
Thermoregulation
- the distribution and redistribution of heat
- helps us maintain thermal balance
- ensures we don’t overheat
- your cv system uses vasoconstriction and vasodilation to distribute heat around your body
Vasodilation
- caused by involuntary muscle fibres in vessel walls relax
- this increases the diameter of blood vessels
- this decreases resistance to the flow of blood to the area supplied by the vessel
- results in a decrease in body temperature
- more blood to skin surface means more heat lost
Vasoconstriction
- blood vessels temporarily shutdown
- blood flow to tissues is limited
- the diameter of blood vessels decreases
- increases body temperature as heat loss is reduced as blood is moved away from the surface of the skin
Fighting infection
- leukocytes (white blood cells) are constantly produced inside the bone marrow
- they are stored in and transported around the body in the blood
- they can identify, consume and destroy pathogens
- white blood cells also help to produce antibodies that will also destroy pathogens
- antitoxins are produced to neutralise the toxins released by pathogens
Clotting of blood
- blood clotting is a complex process during which white blood cells form solid clots
- a damage blood vessel wall is covered by fibrin clot
- platelets form a plug at the site of the cut to stop any more blood from escaping
- components in the plasma known as coagulation factors responsible to form fibrin strands which strengthen the platelet plug
- this is made possible by the constant supply of blood through the cardiovascular system
Nervous control
Electrical system of your heart
Sinoatrial node (SAN)
- heart ‘pacemaker’
- located in wall of right atrium
- SAN sends impulse from right atrium, through walls of atria
- this causes muscle walls to contacts
- this forced blood down the atria into the ventricles
Atrioventricular node (AVN)
- the stimulation to contract produced by the SAN cannot spread to the ventricles due to the valves acting as a physical barrier. So the AVN helps.
- located and conducts impulse between the atria and ventricles
- AVN delays signal, allows atria to contract before ventricles
- ventricles can receive all the blood before its contracts
Bundle of his
- responsible fro transporting impulse from AVN
- found in the septum
Purkinje fibres
- found at the end of the bundle of his
- located in the walls of the ventricles
- the carry impulse to ventricle walls = contract
- the contraction causes blood writhing the ventricles to be pushed up and out of the heart. Either to the lungs or the working muscles.
What is the sympathetic nervous system
Prepares the body for intense physical activity and is often referred to as the fight or flight response
Whats the parasympathetic nervous system
Relaxes the body and inhibits or slows many high energy functions. This is often referred to as the rest and digest response.
What happens to the sympathetic nervous system during exercise
Heart rate beats faster
Lungs work harder
Increase blood pressure to produce more energy to meet demands of exercise
What happens to the parasympathetic energy system after exercise
Heart rate slows to resting levels
Blood pressure reduces
Digestion occurs
What does diastole mean
The relaxation of the heart
What does systole mean
The contraction of the heart
What are the 3 steps of the cardiac cycle
- diastole (all chambers are relaxed, and blood flows into the heart)
- atrial systole (atria contract pushing blood into the ventricles)
- ventricle systole (atria relax, the ventricles contract, pushing blood out of the heart)
What are the responses of the cardiovascular system to a single sport or exercise.
- Anticipatory increase in heart rate prior to exercise
- Increased heart rate
- Increased cardiac output
- Increased blood pressure
- Redirection of blood flow
Anticipatory rise
• Happens prior to sports
• Heart rate rapidly increased by chemicals in the blood and nerves
• Prepares the body for the increased demands about to be put on it
• Greatest anticipatory rise happens before sprint races
Increased heart rate
• Supplies your muscles with more oxygenated blood during exercise
• Nerves centres in the brain detect cardiovascular activity and results in adjustments that increase the rate and
pumping strength of your heart.
• Increase heart rate and contractile force of the heart in proportion to the intensity of the activity undertaken.
Increased cardiac output
• Cardiac Output is the volume of blood
pumped from the heart in one minute
• Is the product of heart rate (BPM) and stroke volume (the amount of of blood per heartbeat).
• Cardiac output = heart rate x stroke volume
• During exercise cardiac output will be greater because of increases in heart rate and/or stroke volume.
• SV increases
• Therefore, cardiac output increases.
• Maximum cardiac output decreases with age
Increased blood pressure
Blood pressure is the force blood exerts against the walls of the arteries.
Systolic pressure
• The pressure exerted on the walls of your arteries when the heart contracts and forces blood out of the heart and into the body
• Increases during exercise
Diastolic pressure
• The pressure on the vessel walls when the heart is relaxed between beats and is filling with blood
• Remains the same, or decreases slightly, during exercise
Redirected blood flow
• Ensures that blood reaches the areas of the body that need it most during exercise (the muscles), your body will redirect and redistribute the flow of blood.
• This ensures maximum amount of oxygenated blood goes to the muscles.
• Less blood delivered to areas of the body that need less oxygen during exercise.
• This is achieved through vasoconstriction and vasodilation
What are the adaptations for the cardiovascular system due to exercise
- Cardiac hypertrophy
- Increased resting and exercising stroke volume
- Decrease in resting heart rate and reduction in resting blood pressure
- Decreased heart rate recovery time
- Capillarisation of skeletal muscle and alveoli
- Increase in blood volume
Cardiac hypertrophy
• Hypertrophy is the enlargement of the heart over a long period of time
• Training causes the walls of the heart to become thicker
• Anaerobic exercise causes the left ventricle walls to become thicker
• Aerobic exercise causes the left ventricle cavity to become larger
• Increasing the strength potential of its contractions
Increased resting and exercising stroke volume
• Stroke volume is the volume of blood
pumped from the heart in one beat.
• The more blood that can be pushed out of
the heart, the more oxygen can get to muscles.
• Both resting and exercising stroke volume
increases over time due to cardiac
hypertrophy.
• The heart can therefore pump more blood
per minute, increasing cardiac output during maximal levels of exercise.
• Blood flow increases because of an increase in the size and number of blood vessels.
• This allows for more efficient delivery of
oxygen and nutrients.
Decrease in resting heart rate and blood pressure
• Cardiac hypertrophy will increase stroke volume through long term exercise and-resting heart rate falls, reducing the workload of the heart.
• Where a person is suffering from high blood pressure, aerobic exercise will reduce this over
Decreased heart rate recover time
• Exercise causes your blood pressure to rise for a short time. When you stop your blood pressure should return to normal.
• The quicker it does this the fitter you are.
• The time taken for heart rate to return to
resting levels after exercise will decrease as an adaptation to exercise.
• Due to the body’s improved ability to transport oxygen and carbon dioxide.
Capillarisation of the skeletal muscle and alveoli
• Long term aerobic exercise can lead to an increase in the number of capillaries which frow in and around the alveoli and in the muscles and heart
• This increases blood flow and greater area for diffusion of oxygen and carbon dioxide
• More efficient delivery of oxygen and nutrients.
Increase in blood volume
• Blood volume is the amount of blood
circulating your body.
• Blood volume increases because of
training.
• Blood volume increases as a result of
capillarisation. Greater blood volume the
more blood will circulate around the body meaning a greater capacity to carry oxygen, carbon dioxide and nutrients to the muscles and other organs
• Your body can also regulate body temperature more efficiently during
What are the additional factors that affect the CV system
- sudden arrhythmic death syndrome SADS
- high blood pressure (hypertension)
- low blood pressure (hypotension)
- hyperthermia
- hypothermia
Sudden arrhymic death syndrome (SADS)
Sudden arrhythmic death syndrome, or SADS, is when there is disruption to the
rhythm of the heart.
A young person (under 35) can die suddenly following a cardiac arrest and there are no obvious causes detected.
This affects around 500 people in the UK every year.
We know that, in many cases, this is caused by an inherited heart condition and the person’s immediate family should be referred to a specialist genetics centre for assessment.
High blood pressure (hypertension)
• When you start to exercise your blood
pressure will increase as your heart works
harder and pushes more blood out of the
heart with greater force.
• If you already have high blood pressure
you suffer from hypertension.
• The sudden increase in demand on the
heart can be dangerous as too much force
may be exerted on the heart and arteries.
• Anyone with hypertension should seek
medical advice before starting an exercise
programme.
Low blood pressure (hypotension)
• Low blood pressure (hypotension) means that your blood is moving slowly around your body, which can restrict the amount of blood reaching vital organs and muscles.
• Low blood pressure can cause dizziness, fainting and tiredness.
• Having low blood pressure, it can be harder for your CV system to respond during exercise. If your muscles are not
receiving enough oxygenated blood this will affect performance.
• If not enough blood is supplied to the brain, then fainting can occur.
• Anyone with hypotension should seek medical advice before starting an exercise programme.
Hyperthermia - too hot
• Hyperthermia is the prolonged increase in body temperature that occurs when the body produces or absorbs too much heat.
• When you exercise your body produces heat as a waste product. Your CV system will regulate your body temperature by dilating the blood vessels closer to the body’s surface and making you sweat so that the heat can dissipate.
• If exercising in hot environment it is difficult for the heat to be removed. Likewise, if you are wearing incorrect clothing that traps the heat then you may suffer from hyperthermia.
Hypothermia - too cold
Is where your body becomes too cold, with your core temperature dropping below 35C (ideal body temperature is 37C). Symptoms include shivering, confusion and in severe cases an increased risk of your heart stopping.
Hypothermia may occur if you are training in a cold environment without adequate clothing.
