The Heart and Circulatory System Flashcards
(121 cards)
1
Q
What must the cells of the body do in order to sustain exercise? And how is this process achieved?
A
They must require a continuous supply of nutrients and their waste products must be removed. This process is achieved by the circulatory system.
2
Q
What is the heart?
A
A muscular pump.
3
Q
What is the job of the heart?
A
To push blood into the tissues.
4
Q
What is the size of the heart?
A
About the size of a man’s clenched fist.
5
Q
Where is the heart located?
A
Behind and to the left of the sternum.
6
Q
What does the heart consist of?
A
Four chambers: two upper, smaller chambers called atria (left and right atrium) and two lower, larger chambers called ventricles.
7
Q
What is the predominant tissue of the heart?
A
Cardiac muscle, which is referred to as the myocardium (‘myo’ refers to muscle and ‘cardiac’ refers to the heart)
8
Q
What is the right hand side of the heart responsible for?
A
Receiving blood from the upper and lower body via the veins.
9
Q
How does blood enter the right atrium?
A
Through either the inferior or superior vena cava.
10
Q
What happens to blood when it enters the right atrium?
A
Is it saturated with CO2 and is referred to as deoxygenated blood. It is ejected to the lungs (pulmonary circulation) by the right ventricle via the pulmonary artery.
11
Q
What happens in the pulmonary capillaries?
A
CO2 diffuses into the lungs to be expired while O2 enters the blood. This oxygenated blood enters the left atrium of the heart via the pulmonary vein. The left ventricle then ejects the blood and O2, via the aorta, to the tissues of the body (systemic circulation).
12
Q
What colour is deoxygenated blood?
A
Dark red.
13
Q
What colour is oxygenated blood?
A
Bright red.
14
Q
Which way do arteries carry blood?
A
Away from the heart.
15
Q
Which way do veins carry blood?
A
To the heart.
16
Q
What does the heart have to do to function effectively as a pump?
A
It needs to direct blood through the atria, ventricles and then the arteries of the body.
17
Q
What does the heart prevent?
A
Unwanted back-flow of blood into the chambers using a number of valves.
18
Q
When do the hearts valves open and close?
A
When in response to changes in pressure as the heart contracts and relaxes.
19
Q
What does the structure of the valves mean?
A
That they only allow blood to flow in one direction by shutting once blood has been pushed through the,. This is fundamental to effective circulation.
20
Q
What does back-flow through the heart compromise and affect?
A
The efficiency of each heartbeat, which is likely to affect exercise performance and health.
21
Q
What are the main valves of the heart?
A
The atrioventricular (AV) valves and the semilunar (SL) valves.
22
Q
Where are the AV valves located?
A
Between the atria and the ventricles.
23
Q
What do the AV valves do?
A
They prevent the back-flow of blood from the ventricles to into the atria.
24
Q
What happens when the ventricles contract?
A
Pressure rises and forces the AV valves to snap shut, allowing blood to be directed through the arteries leaving the heart (pulmonary artery and aorta).
25
Where are the SL valves located?
At the base of the arteries leaving the heart (aorta and pulmonary artery).
26
What happens after each contraction of the SL valves?
There is a relative drop in pressure within the ventricles as they relax. At this point, the blood within the pulmonary artery and aorta could potentially flow back into the ventricles.
27
How is blood, within the pulmonary artery and aorta, that flows back into the ventricles prevented?
Both sets of arteries have SL valves positioned at the point where they emerge from the ventricles, the SL valves snap shut so blood cannot re-enter.
28
What causes the distinct 'Lub-dub' noises associated with the heartbeat?
The sequential shutting of the valves during the cardiac cycle.
29
What happens when the AV valves snap shut?
They are anchored in place by tendon-like chords (chordae tendineae) which prevent the valve flaps from being pushed too far into the atria.
30
What stimulates the heart to contract?
A complex series of integrated systems.
31
What initiates the cardiac muscle contraction?
The heart's pacemaker - the sinoatrial (SA) node.
32
Where is the SA node located?
In the wall of the right atrium.
33
What is the myocardium (heart muscle) simulated to do?
Contract about 72 times per minute by the SA node as part of the autonomic nervous system.
34
What is coronary circulation?
The circulation of blood to the heart.
35
What does the heart require?
A constant supply of oxygen and nutrients; these are carried in the blood.
36
How does the heart achieve a continuous supply of blood?
The heart has its own network of blood vessels. Blood is delivered to the tissues of the heart via two coronary arteries. These arteries branch out from the base of the aorta and and subdivide into a crown-like network of blood vessels across the heart wall. Blood is then circulated through both the superficial and deep tissues of the heart via this network of blood vessels before being drained away through coronary veins.
37
What is the aorta?
The major vessel for removing blood from the left ventricle.
38
What does the right coronary artery do?
Primarily supplies blood to the myocardium of the right ventricle.
39
What does the left coronary artery do?
Divides into two branches, suppling blood to the left ventricle and the posterior of the heart.
40
What are most regions of the heart served by?
More than one branch of coronary arteries.
41
What happens if the blood flow through one vessel becomes reduced (e.g. through heart disease)?
Blood supply to the tissues can be maintained through other vessels.
42
What are the coronary arteries most renowned for?
Their association with heart disease. The flow of blood through these arteries is critical to the health of the heart.
43
What can most heart problems be attributed to?
Poor coronary circulation as a result of blood clots, fatty plaques building up in the coronary arteries or spasms in the smooth muscle of their walls.
44
What can blood clots, fatty plaques and spasms do?
They will reduce the amount of blood flowing through the coronary arteries and therefore decrease the volume of oxygen and nutrients reaching the heart muscle; ultimately this may cause the heart to fail.
45
What is ischaemia?
Reduction in blood flow.
46
What is the myocardium?
The heart muscle.
47
What is myocardial ischaemia?
A reduction in blood flow to the heart through coronary circulation.
48
What can myocardial ischaemia cause?
A myocardial infarction (heart attack).
49
What is infarction?
The death of an area of tissues because of an interrupted blood supply.
50
What happens to the blood flow in a healthy blood vessel?
The blood flows smoothly to reach its target tissues or organ and supply it with the nutrients and oxygen it requires for optimal function.
51
What is vascular disease?
The narrowing of the blood vessels, which has a negative impact on their performance.
52
What is the main cause of death in the developed world?
Vascular disease.
53
How is vascular disease caused?
Inflammation within blood vessels and the subsequent accumulation of mineral, protein and fat deposits, which create a build-up of plaques on vessel walls. This restricts or completely prevents blood flow to tissues and organs, which starves these structures of vital nutrients and oxygen.
54
What are symptoms of vascular disease?
Reduced ability to exercise, bouts of chest pain and heart attacks.
55
What is vascular disease linked to?
Strokes and kidney disease.
56
What is atherosclerosis?
The hardening of the arteries.
57
What condition most commonly causes vascular disease?
Atherosclerosis.
58
What happens if an artery becomes inflamed or damaged?
Plaques form on the artery walls as the body attempts to repair the artery using cholesterol, protein and mineral deposits. As the plaques build up, the artery becomes thicker, harder and less elastic. The artery is then narrower and less able to stretch in response to blood flowing through it, so the amount of blood (and therefore oxygen) that is able to reach a tissue or organ is reduced.
59
What can cause target tissues death?
A lack of blood flow as a result of atherosclerosis in an artery, unless those tissues are supplied by blood from alternative arteries.
60
What does atherosclerosis commonly affect?
The arteries of the heart and brain.
61
What does atherosclerosis produce?
Varying symptoms depending on the tissues involved.
62
What can atherosclerosis be associated with?
Chest pain on exertion that settles with rest.
63
What is 'chest pain on exertion that settles with rest' referred to?
Angina pectoris.
64
What does angina pectoris mean?
'Strangled chest'
65
What is angina pectoris?
It is the direct result of a reduced blood supply to the myocardium.
66
What can an arterial plaque do?
It can rupture, causing a coronary artery to become completely blocked by the resultant blood clot. The section of the heart supplied by that artery will then be deprived of blood and die, causing a heart attack.
67
What causes a heart attack?
If a section of the heart is deprived of blood and therefore dies.
68
What causes a stroke?
Narrowed arteries in the brain which can become blocked by clots.
69
What is another name for a stroke?
Cerebrovascular accident or CVA.
70
When is a more turbulent blood flow likely to occur?
When atherosclerosis is present which can further damage vessel walls, leading to further atherosclerosis and the greater likelihood of clot formation.
71
What factors can play a role in the gradual build-up of plaque within the vessel walls?
A family history, a lack of exercise, stress, an unhealthy diet, being overweight and smoking.
72
What is blood pressure?
A measure of the force that blood applies to the walls of the arteries as it flows through them.
73
How is blood pressure measured?
In millimetres of mercury (mmHg).
74
What is used to measure blood pressure?
A sphygmomanometer.
75
How is blood pressure expressed?
Using two numerical readings.
76
What is the optimal blood pressure reading?
120/80 mmHg.
77
What do the two numbers represent in a blood pressure reading?
The systolic and diastolic pressure readings.
78
What is systolic blood pressure (SBP)?
The pressure exerted on the artery walls during the contraction phase of the heartbeat.
79
What is the higher number of a blood pressure reading?
The systolic blood pressure.
80
What causes systolic blood pressure?
The increase volume of blood flowing through the arteries with each beat, therefore increasing the pressure within the arteries.
81
What is diastolic blood pressure?
The pressure exerted on the artery walls during the relaxation phase of the heartbeat.
82
Why does the heart go through a relaxation (or diastole) phase when beating?
To allow the chambers of the heart to fill with blood prior to contraction.
83
What is the lower number of a blood pressure reading?
The diastolic blood pressure.
84
Blood pressure is an expression of what?
Arterial blood flow and the peripheral resistance the blood encounters as it flows round the body.
85
What sis the equation for measuring blood pressure?
Blood pressure = Cardiac output x Total peripheral resistance.
86
What is cardiac output?
The volume of blood pumped out by the heart in one minute (ml/min).
87
If the cardiac output is greater, is the blood pressure higher or lower?
Higher.
88
What is total peripheral resistance?
The resistance the blood vessels offer to blood flow.
89
If the total peripheral resistance is greater, is the blood pressure higher or lower?
Higher.
90
What increases peripheral resistance?
Constriction.
91
What decreases peripheral resistance?
Dilation of the blood vessels (arterioles).
92
What can happen to your blood pressure when feeling anxious or stressed.
It can increase during exertion.
93
What is hypertension?
A term used to describe blood pressure that is consistently higher than the healthy level when at rest.
94
What does a high SBP (systolic blood pressure) provide and indication of?
The strain on the blood vessels when the heart is attempting to pump out blood.
95
What does a high DBP (diastolic blood pressure) provide an indication of?
The blood vessels have little chance to relax between heartbeats.
96
What does measuring blood pressure provide an indication of?
The health of the vascular system and an overall gauge of a person's health.
97
When would the term 'white coat hypertension' be used?
If you have high blood pressure readings only when you are in a medical setting.
98
What does hypertension increase the risk of?
Ischaemic heart disease and cerebrovascular disease - two of the three biggest killers in the developed world.
99
What does ischaemic disease cover?
a variety of heart conditions including valve disease and more acute problems such as myocardial infarction (heart attack).
100
What does cerebrovascular disease include?
Acute problems such as haemorrhagic and ischaemic stroked disease.
101
What can hypertension cause?
Stress on the small vessels to the retina, which can cause blindness, as well as the small vessels of the kidneys, which can lead to renal failure.
102
What is 120/80 mmHg?
The average resting blood pressure, defined by the American College of Sports Medicine (2014).
103
A blood pressure of 140/90 mmHg is considered high or low?
High.
104
If you have a blood pressure reading of 140/90 mmHg, what should you do?
See your doctor before commencing physical activity programmes.
105
What are readings above 180 systolic and 110 diastolic?
A contraindication for exercise.
106
Should people with low blood pressure readings require medical referral?
Yes.
107
What blood pressure measurements are considered low?
< 100 systolic and <60 diastolic.
108
What blood pressure measurements are considered optimal?
<120 systolic and <80 diastolic.
109
What blood pressure measurements are considered normal?
<130 systolic and <85 diastolic.
110
What blood pressure measurements are considered high normal - pre-hypertension?
130-139 systolic and 85-89 diastolic.
111
What blood pressure measurements are considered stage 1 hypertension?
140-159 systolic and 90-99 diastolic.
112
What blood pressure measurements are considered stage 2 hypertension?
160-179 systolic and 100-109 diastolic.
113
What blood pressure measurements are considered stage 3 hypertension?
>180 systolic and <110 diastolic.
114
What is the most common form of stroke?
Ischaemic stroke.
115
What three things often cause a stroke?
A thrombosis, an amoralism or a detached blood clot (from elsewhere in the body).
116
What is a thrombosis?
An obstruction of a blood vessel leading to the brain by a localised blood clot.
117
What is an embolism?
An obstruction due to an embolus?
118
What is a haemorrhagic stroke?
An intracranial haemorrhage (bleed).
119
What can a haemorrhagic stroke be linked to?
An aneurysm.
120
What is an aneurysm?
A localised, blood-filled, balloon-like bulge in the wall of a weakened blood vessel.
121
What happens as an aneurysm increases in size?
The risk of it rupturing increases.
