1.1 The Cardiovascular System Flashcards
(161 cards)
1
Q
Bradycardia (definition)
A
A decrease in resting heart rate to below 60 beats per minute.
2
Q
Heart Rate`(definition)
A
The number of times the heart beats per minute.
3
Q
Stroke Volume (definition)
A
The volume of blood pumped out by the left heart ventricle in each contraction.
4
Q
Cardiac Output (definition)
A
The volume of blood pumped out by the heart ventricles per minute.
5
Q
Cardiac Output (calculation)
A
Cardiac Output = Stroke Volume x Heart Rate.
6
Q
Ejection Fraction (definition)
A
The percentage of blood pumped out of the left ventricle each beat.
7
Q
Cardiac Hypertrophy (definition)
A
The thickening of the muscular wall of the heart so it becomes larger and stronger; can also lead to developing a larger ventricular cavity.
8
Q
Max Heart Rate (calculation)
A
220 - age (bpm)
9
Q
Resting Heart Rate (definition)
A
The average number of heart beats per minute at rest.
10
Q
What is the average resting heart rate?
A
72 beats per minute
11
Q
Starling’s Law (definition)
A
The greater the venous return, the greater the strength of contraction in the heart.
12
Q
Venous Return (definition)
A
The return of blood to the right side of the heart via the vena cava.
13
Q
The heart muscle is myogenic, state what this means:
A
Myogenic - The capacity of the heart to generate its own impulses.
14
Q
What do Chemoreceptors detect?
A
changes in Carbon Dioxide levels.
15
Q
What do Baroreceptors detect?
A
Changes in the blood pressure (baro = pressure)
16
Q
Suggest why the atria are smaller than the ventricles:
A
The atria only have to push blood down into the ventricles, whereas the ventricles have to push blood out of the heart and therefore have stronger muscle tissue surrounding it.
17
Q
Which side of the heart is larger, and suggest why it is:
A
The left side is larger as it contains more muscular tissue in order to pump blood all around the body as apposed to the lungs (which are in close proximity to the heart).
18
Q
What is the function of the Vena Cava?
A
Transporting de-oxygenated blood to the right atrium of the heart.
19
Q
What is the function of the pulmonary vein?
A
Delivering oxygenated blood to the left atrium.
20
Q
Wht is the function of the pulmonary artery?
A
Leaves the right ventricle with de-oxygenated blood to take to the lungs.
21
Q
What is the function of the aorta?
A
Leaves the left ventricle with oxygenated blood for the body.
22
Q
There are four main valves in the heart, what are their function?
A
Ensures blood flow is unidirectional, it does this by opening to allow blood to pass through and closes to prevent backflow.
23
Q
What valve is located between the right atrium and right ventricle?
A
Tricuspid valve.
24
Q
What valve is located between the left atrium and left ventricle?
A
Bicuspid valve.
25
Where are the semi-lunar valves?
They are found between the right and left ventricles (and the pulmonary artery and aorta).
26
Where does the electrical signal start in the cardiac conduction system?
In the sinoatrial node (SA node).
27
Where is the Sinoatrial node found?
In the wall of the right atrium.
28
Which component of the cardiac conduction system is commonly referred to as "the pacemaker"?
The SA node.
29
Describe the consequences of an electrical impulse being sent out of the SA node:
The impulse spreads through the atrial walls, causing them to contract and forcing blood into the ventricles.
30
What does the abbreviation AV node mean?
Atrioventricular node.
31
What is the function of the AV node?
The node relays the impulse (created by the AV node) between the upper and lower sections of the heart.
32
Approximately how long does the AV node delay the impulse, and what is the purpose of this delay?
0.1 seconds, it is to allow for full contraction of the atria before ventricular systole begins.
33
Where is the bundle of his located?
In the interventricular septum, (between the left and right ventricles).
34
State the function of the bundle of his:
It transmits the electrical impulses from the AV node to the ventricles in order to stimulate ventricular systole.
35
As an electrical impulse goes down the bundle of his, it splits into two branches before reaching a group of smaller bundles, what is the name of these muscles?
Purkinje fibres.
36
What is the function of purkinje fibres?
To conduct impulses in the walls of the ventricles in order to stimulate contractions.
37
What is the scientific name for contraction?
Systole.
38
What is the mnemonic used to summarise the cardiac conduction system?
```
S AN
A trial systole
A VN
B undle of his
P urkinje fibres
V entricuar systole.
```
39
What is the sympathetic (nervous) system?
A part of the autonomic nervous system that speeds up heart rate.
40
What is the parasympathetic (nervous) system?
A part of the autonomic nervous system that slows down heart rate (to resting levels).
41
Which body parts make up the Central Nervous System?
The spinal cord and the brain.
42
What is the peripheral nervous system?
Nerve cells which transmit information to and from the CNS.
43
Both the Central and Peripheral nervous systems are controlled by the same part of the brain, what is the name of this?
Medulla Oblongarta.
44
What are the 3 types of "detectors" that feedback to the medulla oblongarta.
Chemoreceptor
Baroreceptor
Proprioceptors
45
What do chemoreceptors detect?
Changes in Carbon Dioxide levels.
46
Where are chemoreceptors found?
Carotid arteries.
| Aortic arch.
47
Why is the chemoreceptor important during exercise?
Due to increased rate of respiration, CO2 levels increase. The chemoreceptors detect this and stimulate the sympathetic nervous system to increase heart rate and get rid of CO2.
48
What do baroreceptors detect?
Changes in blood pressure.
49
How do baroreceptors detect changes in blood pressure?
They have nerve endings that respond to the stretching of the arterial walls caused by pressure.
50
Blood pressure naturally increases during exercise, how do baroreceptors deal with this without setting off a false alarm to the medulla oblongarta.
They set a point for natural blood pressure level during exercise when it begins so that changes are relative to activity levels.
51
What do proprioceptors detect?
They detect and increase in muscle movement.
52
When proprioceptors detect increased muscle movement at the start of exercise, what happens?
The receptors send an impulse through the sympathetic nervous system to the SAN to increase heart rate.
53
What effect does the hormone adrenaline have on thee SA node?
It increases both the speed and force of impulses, increasing cardiac output as the heart rate increases. Resulting in more oxygen being supplied to the working muscles.
54
What is the stroke volume?
The volume of blood being pumped out by the heart ventricles in each cardiac contraction.
55
What is venous return?
The volume of blood returning to the heart through the veins.
56
What is the relationship between venous return and stroke volume?
If venous return increases, so will stroke volume as more blood enters the heart meaning more blood leaves the heart.
57
What is the diastole phase?
The phase in which the heart muscle relaxes to fill with blood.
58
What is ejection fraction?
The percentage of blood pumped out by the left ventricle per beat.
59
What is myocardium? (H)
The muscle tissue of the heart.
60
What is the average stroke volume at rest? (H)
70 ml
61
Explain the equation:
| Q = SV x HR
```
Q = Cardiac Output
SV = Stroke Volume
HR = Heart Rate
```
Cardiac Output = Stroke Volume x Heart Rate.
62
What is Starling's Law?
```
Increased venous return,
Greater diastolic filling,
Cardiac muscle stretches,
More contraction force,
Increased ejection fraction.
```
63
Maximum heart rate calculation:
220 - age (bpm)
64
Explain how an individual can undergo cardiac hypertrophy:
Regular aerobic training leads to the development of cardiac muscle, this is hypertrophy.
65
Which of the body's systems involve the heart and blood vessels?
The cardiovascular system.
66
State the term used to describe the increase in heart rate before exercise and name the hormone that causes this increase:
Anticipatory rise caused by the fight or flight response due to release of adrenaline into the bloodstream.
67
What is the function of the parasympathetic nervous system:
To slow the heart rate back to resting level.
68
What is in the autonomous nervous system:
The sympathetic nervous system and the parasympathetic nervous system.
69
Which nervous system causes a 'fight or flight' response?
The sympathetic nervous system.
70
What is the function of the sympathetic nervous system?
Stimulates a flight, fright (or freeze) response by raising heart rate and releasing adrenaline.
71
Which of the autonomic nervous systems uses the vagus nerve?
Parasympathetic nervous system.
72
What is atrial systole?
The contraction of both the left and right atria at the same time, forcing blood into the ventricles due to increased blood pressure.
73
What is ventricular systole?
The contraction of both the left and right ventricles at the same time forcing blood out of the heart due to increased blood pressure.
74
What is cardiac diastole?
The period of time in which the heart relaxes after contraction in preparation for the refilling of blood.
75
What is ventricular diastole?
When the ventricles relax to allow blood into them from the atria.
76
What is atrial diastole?
When the atria relax to allow blood in.
77
When ventricular diastole and atrial diastole occur together, what is this referred to as?
Complete cardiac diastole.
78
Which gland releases adrenaline and where is it located?
The adrenal gland which is located on the top of the kidneys.
79
Anticipatory rise results in the activation of which nervous system?
Sympathetic.
80
Why would vasodilation occur during exercise?
The blood vessels would open to allow blood to get to the working muscles to provide oxygen.
81
Why would vasoconstriction occur during exercise?
To reduce the amount of blood that travels to areas where it is not needed, such as the digestive system.
82
Why does the brain always have a large blood flow?
To maintain brain function as this controls what we do.
83
During which process would the lumen of a vein increase?
Vasodilation.
84
During which process would the lumen of a vein decrease?
Vasoconstriction.
85
Which type of receptor is located in the aortic arch?
Chemoreceptors.
86
Which type of receptor is commonly found in muscles, tendons, joints and the inner ear?
Proprioceptors.
87
Is bradycardia more likely to occur in a trained heart or an untrained heart?
A trained heart is more likely to have a lower heart beat.
88
Is athletes heart more likely to occur in a trained heart or an untrained heart?
Trained heart (obviously)
89
Which is more likely to have a greater ejection fraction during exercise, a trained heart or an untrained heart?
A trained heart.
90
Explain a muscle pump mechanism in venous return:
The muscles contract and squeeze the blood in the veins which pushes it up towards the heart.
91
Where is a muscle pump mechanism likely to be used in the body?
The legs and lower body where gravity acts negatively on the desired direction of blood flow.
92
What is the respiratory mechanism in venous return?
The breathing muscles, such as abs and intercostal muscles contract and push blood up towards the heart.
93
Where is the respiratory mechanism for venous return likely to happen?
In the torso / chest area.
94
Explain the role of pocket valves in veins:
They open and close to allow blood to pass through the veins, but stop backflow through them to prevent clogging or build-up.
95
Calculate the maximum heart rate for someone aged 57:
220 - age
220 - 57
= 163 beats per minute.
96
Explain why a performer may reach a stroke volume plateau, (where stroke volume does not increase).
Because the heart rate is so great that ventricles do not have sufficient time to fill with blood and therefore less blood can be ejected from the heart.
97
What is the name of the disease that is the leading cause of death in the UK and around the world, caused by a build up of fatty tissues in the veins?
CHD (Coronary Heart Disease)
98
What is atherosclerosis?
The hardening and narrowing of arteries as they become clogged by fatty acids.
99
What disease is caused by atherosclerosis?
Coronary Heart Disease (CHD).
100
What are atheroma?
Fatty deposits found in the inner lining of an artery.
101
What can atherosclerosis be caused by?
- High blood pressure,
- High level of cholesterol,
- Lack of exercise,
- Smoking.
102
What is angina?
Chest pain that is caused when the blood supply through the coronary arteries is restricted.
103
What effect would regular aerobic exercise have on blood pressure?
Regular aerobic exercise would reduce blood pressure.
104
What are the two types of cholesterol?
LDL (Low density lipoproteins)
| HDL (High density lipoproteins)
105
What do Low density lipoproteins do?
They transport cholesterol in the blood to the tissues.
106
Which type of cholesterol is linked to increased risk of heart disease?
Low density lipoproteins - LDL
107
What do High density lipoproteins do?
They transport excess cholesterol in the blood back to the liver where it is broken down.
108
Which type of cholesterol is linked to lowering the risk of heart disease?
High density lipoproteins - HDL
109
Which type of cholesterol are known as 'good' cholesterol?
High density lipoproteins - HDL
110
Which type of cholesterol are known as 'bad' cholesterol?
Low density lipoproteins - LDL
111
What does regular physical exercise do to cholesterol levels?
Regular exercise lowers the 'bad' LDL cholesterol levels and significantly increases 'good' HDL cholesterol levels.
112
When does a stroke occur?
When the blood supply to part of the brain is cut off causing damage to brain cells so they start to die.
113
What are the two main types of stroke?
- Ischaemic strokes
| - Haemorrhagic strokes
114
Which type of strokes are more common?
Ischaemic strokes are more common.
115
When does an ischaemic stroke occur?
When a blood clot stops the blood supply to the brain.
116
When does a haemorrhagic stroke occur?
When a weakened blood vessel supplying the brain bursts.
117
What effect does regular exercise have on the risk of a stroke?
Regular exercise helps lower blood pressure and reduce the risk of stroke.
118
What is steady state?
Where the athlete is able to meet the oxygen demand with the oxygen supply.
119
What is the function of the vascular system?
The series of blood vessels that carry blood through the body. They deliver oxygen and nutrients to the body tissues and take away waste products such as carbon dioxide.
120
What are the two types of circulation?
Pulmonary
| Systematic
121
What is pulmonary circulation?
Deoxygenated blood from the heart to the lungs and oxygenated blood hack to the heart.
122
What is systematic circulation?
Oxygenated blood to the body from the heart and then the return of deoxygenated blood from the body to the heart.
123
Describe the route of oxygenated blood from the heart back into the heart as deoxygenated blood:
```
Heart,
Arteries,
Arterioles,
Capillaries,
Venules,
Veins,
Heart.
```
124
What is the pressure of the blood in the veins?
Low pressure
125
What is the pressure of the blood in the arteries?
High pressure
126
What is the equation for blood pressure?
Blood pressure = blood flow x resistance
127
What is systolic pressure?
The pressure in the arteries when the ventricles are contracting.
128
What is diastolic pressure?
The pressure in the arteries when the ventricles are relaxing.
129
In which artery is blood pressure usually measured out of?
The brachial artery (in the upper arm)
130
How many oxygens can be carried by one haemoglobin molecule (and suggest why).
4 - there is one for each haem group.
131
What is formed when oxygen combines with haemoglobin?
Oxyghaemoglobin.
132
What is oxyhaemoglobin dissociation?
Where the oxygen in oxyhaemoglobin is released (to the working muscles).
133
What is myoglobin?
An iron containing muscle pigment in slow-twitch muscle fibres that store oxygen to be used when exercise starts.
134
Why does oxygen leave the oxyhaemoglobin and go the the myoglobin?
Myoglobin has a slightly higher affinity for oxygen than haemoglobin.
135
Why do mitochondria require oxygen?
For aerobic respiration.
136
Would an increase in carbon dioxide lead to a higher or lower pH value in the blood?
Lower as carbon dioxide is acidic and therefore has a pH below 7 (neutral)
137
What is the vascular shunt mechanism?
The redistribution of cardiac output.
138
What is the Aterio-venous difference?
The difference between the oxygen content of the arterial blood arriving at the muscles and the venous blood leaving the muscles.
139
What does A-VO2 diff stand for?
Arterio-venous difference.
140
What affect does exercise have on the A-VO2 diff?
It increases the difference as more oxygen is required by the muscles as they are working harder.
141
State a time when you have noticed yourself having an anticipatory rise:
Before a boxing fight or rugby game.
142
Which receptor is responsible for detecting a change in blood pressure?
Baroreceptor.
143
What happens to the viscosity of blood during exercise?
The viscosity increases, making it harder to circulate around the body.
144
What happens to the stroke volume during a cardiac drift?
It undergoes an initial fast increase then slowly decreases at a shallow gradient.
145
Where is myoglobin found and what is its role during exercise?
It is found in the muscles, it recieves oxygen from the haemoglobin in RBC's and distributed it across the muscle cell for respiration.
146
Why does oxygen get released from the haemoglobin into the myoglobin?
Myoglobin has a higher affinity for oxygen.
147
Put simply, what causes the Bohr shift to occur?
The bi-products of exercise.
148
Which receptor is located in the carotid artery?
Chemoreceptors.
149
Which receptor is located in the aortic arch?
Chemoreceptors.
150
What is the cardiovascular drift?
The increase in heart rate caused by more viscous blood due prolonged exercise, despite the intensity of exercise staying the same.
151
T / F - a cardiovascular drift occurs only when there is an increase in intensity of exercise.
False - it occurs when exercise is done at a steady intensity.
152
What physiological change happens to cause the cardiovascular drift?
The viscosity of the blood increases due to fluid loss (sweating) and increased core temperature.
153
What may occur due to fluid loss (sweating) and / or increased core body temperature?
Cardiovascular drift.
154
What can be done to prevent a cardiovascular drift from occurring?
Taking in lots of fluids before and during exercise to prevent blood becoming viscous.
155
What two systems work in unison to make the cardio-respiratory system?
Cardiovascular system.
| Respiratory system.
156
What is cardiac output?
The volume of blood leaving the left ventricle per minute.
157
How is cardiac output calculated?
CO = SV x HR.
| Cardiac Output = Stroke Volume x Heart Rate.
158
What is Stroke Volume?
The volume of blood ejected from left ventricle per beat.
159
What is Ejection Fraction?
The proportion of blood leaving the left ventricle per beat.
160
What is Starling's Law?
States that the greater the venous return, the greater the strength of contraction in the heart.
161
How is Maximal Heart Rate calculated?
220 - age bpm.
