Cardio-vascular System Flashcards
(60 cards)
1
Q
What does physical activity impact in health?
A
- heart disease
- high blood pressure
- effects of cholesterol
- stroke
2
Q
What does physical activity impact in fitness?
A
- cardiac output
- stroke volume
- heart rate
3
Q
How does physical activity impact heart disease and describe what it is?
A
- helps to prevent CHD
- process of CHD is called atheosclerosis and the fatty deposis are called atheroma
- high blood pressure, high levels of cholesterol, lack of excercise and smoking cause atherosclerosis
- limits supply of O2 to the heart resulting in a heart attack
4
Q
How does physical activity impact high blood pressure and describe what it is?
A
- the force exerted by the blood against the blood vessel walls
- high BP can put extra strain on the heart
- if untreated can lead to heart attack, kidney disease, stroke or dementia
- regular aerobic excercise can reduce blood pressure
- lowers systolic and diastolic pressure
5
Q
How does physical activity impact the effects of cholesterol and describe what it is?
A
- consists of two types of lipoproteins LDL and HDL
- LDL is low density and transports cholesterol to the tissues and is linked to increased risk of heart disease
- HDL is high density and transports extra cholesterol back to the liver to be broken down and lowers the risk of heart diseas
- regular physical activity lowers bad LDL and increases good HDL
6
Q
How does physical activity impact stroke and describe what it is?
A
- occurs when blood supply to the brain is cut off, lading to the death of the brain cells
- can lead to brain injury, disability and death
- ischaemic stroke is when a blood clot stops the blood supply
- haemorrhagic stroke is when a weakened blood vessel bursts
- regular exercise helps to lower BP and helps maintain a healthy weight
- this decreases chance of stroke by 27%
7
Q
How does physical activity impact stroke volume and what is it?
A
- volume of blood pumped out by the heart in each contraction
- SV is increased by increased venous return, greater elasticity of cardiac fibres and greater contractility of cardiac tissue
- SV increases as exercise intensity increases
- once a performer reaches 60% of max effort SV plateaus because ventricles do not have time to fill up
8
Q
How does physical activity impact heart rate and describe what it is?
A
- number of times the heart beats per minute
- HR increases in direct proportion to exercise intensity
- max HR is calculated by subtracting your age from 220
- Experts have a larger HR range due to a lower resting HR and higher max HR
- regular aerobic exercise results in cardiac hypertrophy
- stronger heart leads to higher SV and lower HR
9
Q
How does physical activity impact cardiac output and describe what it is?
A
- volume of blood puped out by the heart per minute
- Q = SV x HR
- when exercising Q increases due to an increase in HR and SV
- Q increases until max intensity is reached and then it plateaus
- Experts have higher SV but lower HR so their Q is equal to an untrained person
- Increased Q means you transport more blood to working muscles and therefore more O2 so it is easier to work at a higher intensity for longer
10
Q
Where is the cardiac control centre found?
A
Medulla oblongata
11
Q
What is the cardiac control centre connected to and how?
A
Sino atrial node via the peripheral nervous system
12
Q
What does the peripheral nervous system consist of?
A
Parasympathetic and sympathetic nervous systems
13
Q
What does the sympathetic nervous system do?
A
- prepares the body for exercise
- fight or flight
- increases heart rate
- connected via accelerator nerve
14
Q
What does the parasympathetic nervous system do?
A
- relaxes the body
- rest and digest
- decreases heart rate
- connected via vagus nerve
15
Q
What are the three ways of regulating heart rate?
A
Hormonal, neural and chemical
16
Q
What does neural regulation involve?
A
Sypathetic and parasympathetic nervous systems
17
Q
What does chemical regulation involve?
A
Receptors and O2, CO2 and pH levels of the blood
18
Q
What do chemoreceptors do and where are they found?
A
- detect changes in the blood acidity (caused by change in CO2 conc.)
- carotid and aortic arch
19
Q
What do baroreceptors do and where are they found?
A
- detect changes in blood pressure
- heart/pulmonary vessels, aortic arch and carotid sinus
20
Q
What do proprioceptors do?
A
Detect changes in muscle movement
21
Q
How is heart rate regulated by chemoreceptors? (increase)
A
- increase in blood CO2 conc.
- decrease in blood pH
- chemoreceptors detect change
- send impulse to CCC
- sympathetic nervous impulse sent down accelerator nerve to SAN
- heart rate increases
22
Q
How id heart rate regulated by baroreceptors? (decrease)
A
- increase in blood pressure
- baroreceptors detect changes
- send impulse to CCC
- parasympathetic nervous impulse sent down vagus nerve to SAN
- heart rate decreases
23
Q
How is heart rate regulated by propriocepptors? (increase)
A
- increase in muscle movement
- proprioceptors detect changes
- send impulse to CCC
- sympathetic nervous impulse sent down accelerator nerve to SAN
- heart rate increases
24
Q
What is adrenaline?
A
Stress hormone released by the nervous system to increase heart rate
25
What is anticipatory rise?
When heart rate increases prior to exercise
26
How does anticipatory rise happen?
Adrenaline is released by the nervous system in anticipation to exercise which stimulates the heart o increase rate and force of the contractions by affecting the SAN directly
27
What is the effect of anticipatory rise?
Cardiac output increases so more blood is pumped to the working muscles so they recieve more O2
28
What is intrinsic control of the heart rate?
- the heart contains receptors that detect the changes in temperature
- when they detect a change it affects the contractility of the heart
- makes it increase which increases venous return, stretching the heart more and further increasing contractility
29
What is vascular shunting?
Redistribution of blood to where O2 is needed the most
30
Where is blood distributed to during exercise?
- more blood goes to the heart, muscles and skin
- blood flow to the brain remains constant
- blood flow to the gut decreases
31
What is vasoconstriction?
Narrowing of blood vessels to decrease the flow of blood into the capillaries
32
What is vasodilation?
Widening of blood vessels to increase the flow of blood into th capillaries
33
How does the medulla oblongata control vacoconstriction and vasodilation?
- receptors send impulses to vasomotor centre in the medulla oblongata
- medulla oblongata send impulses down the peripheral nervous system to create a response
- sympathetic nervous system causes vasoconstriction
- parasympathetic nervous system causes vasodilation
34
What word means the heart controls its own beat?
Myogenic (impulse generated at SAN)
35
Explain the cardiac conduction system
- impulse originates at SAN
- impulse is sent through walls of the atria as a wave of excitation
- causes atrial systole
- impulse passes to AVN
- delayed for 0.1 sec to allow atria to fully empty
- sent down the bundle of His in the septum of the heart down to the apex
- passes through the purkinje fibres in the walls of the ventricles
- ventricular systole
- contracts from the bottom up
36
How is oxygen transported in the body?
Via arteries, arterioles, capillaries, venules and veins
37
What is the structure of veins and what is there function?
- thin muscle/elastic tissue layer, wide lumen & valves
- carry deoxygenated blood back to the heart
- lower blood pressure
38
What is the structure of the arteries and what is there function?
- thick elastic outer wall, thick layer of muscle, small lumen & smooth inner layer
- carry oxygenated blood around the body
- higher blood pressure
39
What is the structure of capillaries and explain why?
- **very small lumen** only one RBC can pass at a time to slow blood flow down which allows the exchange of nutrients with the tissues by diffusion
- **one cell thick** allows for a short diffusion path
40
What is haemoglobin?
A protein found in RBC that binds to oxygen to form oxyhaemoglobin
41
What is myoglobin?
A protein found in the muscles which bind to oxygen so it can store and provide it to the mitochondria in muscle cells
42
What is the oxyhaemoglobin dissociation curve?
A graph that displays how haemoglobin carries and releases oxygen by showing % saturation of O*2* and the partial pressure of O*2*
43
What is the difference between the % saturation of O*2 *at the lungs compared to the tissue
- at the lungs there is a high partial pessure of O*2* which means that haemogllobin is almost fully saturated
- at the tissues the partial pressure of O*2* is lower meaning that the haemoglobin dissociates some of its O*2* to the tissues
44
Which way does the dissociation curve move during exercise?
| Bohr shift
Right
45
What is the Bohr shift?
When muscles require more oxygen the dissociation of oxygen from haemoglobin to the muscle tissue happens more readily
46
What causes the Bohr shift?
- inrease in temperature
- increase in partial pressure of CO*2*
- decrease in pH
47
What is venous return?
The return of the blood to the right side of the heart through the vena cava
48
What are the mechanisms for venous return?
- skeletal muscle pump
- respiratory pump
- pocket valves
- smooth muscle in veins
- heart pump
49
How do the venous return mechanisms work?
- **skeletal muscle pump** when muscles contact and relaxt they change shape and press on nearby veins which pushes the blood towards the heart
- **respiratory pump** during respiration there are pressure changes in the thorax which compress nearby veins and push blood back to the heart
- **pocket valves** prevent backflow
- **smooth muscle in veins** contracts to push blood back towards the heart
- **heart pump** when the heart contracts and relaxes results in suction which pulls blood back towards the heart
50
What is blood pressure and what is the calculation?
- the force exerted by blood againts the blood vessel walls
- blood flow x resistance
51
What is systolic pressure?
The pressure when the ventricles are contracting
52
What is diastolic pressure?
The pressure when the ventricles are relaxing
53
What is the relationship between blood pressure and venous return?
- as systolic blood pressure increases, venous return increases
- - as systolic pressure decreases, venous return decreases
54
What does starling's law of the heart explain?
- during exercise there is an increase in venous return
- caused by greater diastolic filling of the heart
- cardiac muscle stretches more resulting in a more forceful contraction
- increases ejection fraction
55
What is ejection fraction?
The percentage of blood pumped out by the left ventricle per beat
56
What is cardiovascular drift?
A progressive rise in heart rate despite exercise intensity remaining constant
57
What causes cardiovascular drift?
- happens during prolonged exercise in a warm environment
- causes a reduction of plasma volume due to increased sweating
- causes viscocity of the blood to increase which also increases the resistance
- reduces venous return and stroke volume
- heart rate increases to compensate and maintain cardiac output
58
When does cardiovascular drift begin to occur?
After 10 / 20 min
59
What is arteriovenous oxygen difference?
| A-VO*2* diff
The difference between oxygen content of the arterial blood compared to the venous blood
60
How does exercise affect A-VO*2* diff and why?
- it increases it
- more oxygen is extracted by the muscles from the blood to use for energy
- for trained performers to extract greater amounts of oxygen they should train regularly
