The Cardiovascular System Flashcards
What is health?
Complete physical, mental and social well-being
What is fitness?
The ability to meet the demands of an environment
What is atherosclerosis?
Occurs when arteries harden and narrow as they become clogged by fatty deposits
What is angina?
Chest pains that occur when the blood supply through coronary arteries to the muscles of the heart are restricted
What is atheroma?
A fatty deposit in the inner lining of an artery
What is stroke volume?
The volume of blood pumped out by the heart ventricles in each contraction
What is cardiac output?
The volume of blood pumped out by the heart ventricles per minute
What lifestyle choices can lead to a lower chance of heart disease/stroke?
- Exercising regularly
- No smoking
- No alcohol
- No drugs
- Good sleep
- Diet
What is a stroke?
The loss of blood to the brain
How does physical activity reduce the likelihood of a stroke?
Keeping healthy through exercise increases the blood flow to the brain, preventing the brain from being starved of oxygen
What is cholesterol?
High cholesterol restricts the amount of blood flow through the vessels
How does physical activity affect the likelihood of high cholesterol?
Increases the amount of high-density lipoproteins, and decreases the amount of low-density lipoproteins, which prevents a build up of deposits in blood vessels
What is high blood pressure?
Blood pumping through blood vessels with more force than normal
What is heart disease?
A type of disease that affects the heart
How does physical activity affect the likelihood of heart disease?
Exercise keeps cardiac muscles strong and healthy, including the blood vessels, which remains flexible, allowing blood to pass through easily
What are 3 sports that require good cardiovascular fitness?
- Rowing
- Cycling
- Long distance running
How to calculate cardiac output?
Cardiac output = Heart rate x Stroke volume
What is maximal intensity?
The higher intensity of exercise, one rep max
What is sub-maximal intensity?
Repeated exercise but at a lower intensity
What is sub-maximal intensity?
Repeated exercise but at a lower intensity
What is the parasympathetic nervous system?
Part of the ANS and can activate a decrease in heart rate
What is the sympathetic nervous system?
Part of the ANS and can activate an increase in heart rate
What is vascular shunting?
The redistribution of blood flow around the body
What is myogenic?
The heart’s ability to create its own contractions
What are chemoreceptors?
Receptors responsible for detecting a change in CO2/lactic acid/blood acidity
What are baroreceptors?
Receptors responsible for detecting a change in blood pressure
What are proprioceptors?
Receptors responsible for detecting the change in muscle movement
What is anticipatory rise?
This is an increase in heart rate that occurs just before taking part in physical activity
What is vasodilation?
The widening of blood vessels to increase the flow of blood into the capillaries
What is vasoconstriction?
The narrowing of blood vessels to reduce the flow of blood into the capillaries
What is the medulla oblongata?
The most important part of the brain that regulates processes that keep us alive e.g. breathing and heart rate
What is adrenaline?
A stress hormone that is released by sympathetic nerves and cardiac nerves during exercise which causes an increase in heart rate
What is the sinoatrial node (SAN or SA node)?
A small mass of cardiac muscle found in the wall of the right atrium that generates the heart beat (more commonly called the pacemaker)
What is the atrioventricular node (AVN or AV node)?
A node that relays the impulse between the upper and lower sections of the heart
What is systole?
When the heart contracts
What is the Bundle of His?
A collection of heart muscle cells that transmit electrical impounds from the AVN via the bundle branches to the ventricles
What are the purkinje fibres?
Muscle fibres that conduct impulses in the walls of the ventricles
What causes anticipatory rise?
Increase in activity in the sympathetic nervous system
Why is the redistribution of blood important?
- Increases the supply of oxygen to the working muscles
- Removes waste products from the muscles (e.g. carbon dioxide and lactic acid)
- Ensures more blood goes to the skin during exercise to regulate body temperature and get rid of heat through regulation, evaporation, and sweating
- Directs more blood to the heart as it is a muscles and requires extra oxygen during exercise
What is the first process of vascular shunting?
An increase in CO2 and lactic acid is dented by the chemoreceptors
What is the second process of vascular shunting?
The chemoreceptors stimulate the vasomotor (in the brain)
What is the third process to vascular shunting?
The vasomotor signals for a redistribution of blood flow
What is the fourth (and final) process to vascular shunting?
Vasodilation and vasoconstriction occur and pre-capillary sphincters adjust blood flow into the capillaries
What chambers of the heart are larger and why?
The ventricles, as they need to contract to be able to pump blood out of the heart
What side of the heart is larger and why?
The left side, as it pumps blood around the body
What is the main function of the valves?
The valves open and close to stop back flow of blood and allows blood to enter the next chamber
What is the order of the vascular systems blood vessels?
Heart -> Arteries -> Arterioles -> Capillaries -> Venules -> Veins -> Heart
What is the first event in the cardiac conduction system?
Electrical signals begins in the sinoatrial node
What is the second event in the cardiac conduction system?
The electrical impulse travels through the atria, causing them to contract and pass blood into the ventricles, before reaching the atrioventricular node
What is the third event in the cardiac conduction system?
A delay of 0.1 seconds then occurs whilst the atria fully contracts
What is the fourth event in the cardiac conduction system?
The electrical impulse travels down the bundle of his, which is located in the septum
What is the fifth event in the cardiac conduction system?
The bundle of his then separates into smaller branches called the purkinje fibres. These spread around the ventricles and cause then to contract
What do the chemoreceptors do?
Detect changes in CO2 and lactic acid in the blood
What do the baroreceptors do?
Detects a change in blood pressure
What do the proprioceptors do?
Detects a change in movement in the muscles and tissues
What is a part of the hormonal control?
Adrenaline
What is the intrinsic control?
The heart sense changes in temperature and contractility
How do chemoreceptors work?
During exercise, chemoreceptors detect and increase in carbon dioxide in the blood. Nervous impulses are sent to the medulla oblongata, the sympathetic nervous system is activated and impulses are sent to the SA node for contractions to increase. This leads to an increase in heart rate and the supply of oxygen for the body
How do baroreceptors work?
Baroreceptors detect an increase/decrease in blood pressure by the arterial wall stretching. An increase in pressure causes the baroreceptors to send a message to the medulla oblongata. The parasympathetic nervous system is activated and impulses are sent to the SA node for contractions to decrease.
What do the baroreceptors do during exercise?
The set point increases, so that the heart rate does not slow down
How do the proprioceptors work?
Located in the muscles, joints, and tendons, detect an increase of muscle movement during exercise which sends an impulse to the medulla oblongata, activating the sympathetic nervous system. An impulse is sent to the SA node and heart rate is increased.
How does cardiovascular drift occur?
Over a long period of time -> heart rate increases -> stroke volume decreases -> fluid lost via sweat -> reduced plasma volume -> reduced venous return -> cardiac output increased as more energy is needed to cool the body
What is plasma?
The liquid in blood
What is myoglobin?
An oxygen binding protein found in muscle tissue
What is haemoglobin?
An oxygen binding protein found in red blood cells
What is oxyhemoglobin?
Found when oxygen combines with haemoglobin
What is mitochondria?
The part of the cell where respiration and energy production occurs
What is the dissociation curve?
A graphical representation of the rate at which oxygen separates from haemoglobin and diffuses into the muscle cells
What is the Bohr Shift?
The shift to the right that the dissociation curve makes during exercise
What does Hb stand for?
Haemoglobin
What is Mb?
Myoglobin
What does the dissociation curve explain?
The different partial pressure of oxygen in different areas of the body, have an effect on the amount of oxygen combining with haemoglobin
What does the Bohr Shift do?
- Lower pH
- Presence of CO2
- Lactic acid
- Increase in temperature
Why does an increase in oxygen dissociation from haemoglobin happen?
- Increase in blood temperature
- Partial pressure of carbon dioxide increases
- An increase in carbon dioxide means a decrease in pH level of blood, making it more acidic
What is venous return?
The flow of the blood back to the heart via the veins, specifically the vena cava
What is Starling’s Law?
Stroke volume increases due to an increase in venous return
What is diastole phase?
When the heart relaxes to fill with blood
What is ejection fraction?
The percentage of blood pumped out by the left ventricle per beat
What is the steady state?
Where the athlete is able to meet the oxygen demand with the oxygen supply
What is the skeletal muscle pump?
Muscles are contracting and relaxing, always changing shape, which results on muscles pressing against surrounding veins, which causes a pumping action, which pushes blood back towards the heart
What 3 factors is venous return aided by?
‘Smooth muscle’, ‘gravity’, ‘suction pump’ of the heart
What is systolic pressure?
The force of the contraction
What is blood pressure?
The force excreted on the arterial walls
What does Starlings Law state?
The stroke volume increase in response to an increase in venous return
What are the 5 steps that contribute to Starling’s Law?
- Increase in venous return
- Therefore greater diastolic filling of the heart
- Causes cardiac muscles to be stretched
- Resulting in more powerful contractions
- Increased ejection fraction (stroke volume)
What as an anterior-venous oxygen difference (a-VO2 dif)?
The difference in the volume of oxygen between the arteries and the veins
How does the volume of oxygen differ between artery and vein?
- Arteries carry a much higher volume of oxygen that the veins
- Because arteries are carrying oxygen in order to supply the muscles with energy
