Applied Anatomy And Physiology - Cardiovascular System Flashcards
What is diastole
The term used to describe the relaxation phase of the cardiac cycle
What is systole
The term used to describe the contraction phase of the cardiac cycle
Describe the pathway of the blood in 14 steps
1) Vena cava
2) Right atrium
3) Tricuspid valve
4) Right ventricle
5) Pulmonary semilunar valves
6) Pulmonary artery
7) Lungs
8) Pulmonary veins
9) Left atrium
10) Bicuspid valves
11) Left ventricle
12) Aortic semilunar valves
13) Aorta
14) Body
Name the 5 components of the cardiac conduction system
- Sinoatrial node
- Atrioventricular node
- Bundle of his
- Bundle branches
- Purkinjie fibres
Define stroke volume
The amount of blood ejected from the heart per beat
Define cardiac output
The amount of blood ejected from the heart per minute
Define anticipatory rise
This is when there is a slight increase in your heart rate before activity due to the expectation of exercise.
What hormone triggers the anticipatory rise to occur
Adrenaline
How is the heart myogenic
The heart is myogenic as it produces it’s own impulse
Where is the impulse created in the heart?
The SAN (Sinoatrial node)
What three mechanisms control the rate of fire of impulses of the SAN (Sinoatrial node).
- Sympathetic nervous system
- Parasympathetic nervous system
- Medulla Oblongata
What is the sympathetic system
A part of the nervous system that speeds up your heart rate
What is the parasympathetic system
A part of the nervous system that decreases your heart rate
What does the medulla oblongata do
It regulates processes that keep us alive such as our breathing and heart rate.
What are the three receptors within the cardiac system
- Chemoreceptors
- Baroreceptors
- Proprioceptors
What do the chemoreceptors detect and what is their response?
The chemoreceptors will detect an increase in CO2 and it’s response will be to increase the individual’s heart rate.
What do the baroreceptors detect and what is their response?
They detect an increase in blood pressure and their response is to cause a decrease in the individual’s heart rate
What do the proprioceptors detect and what is their response?
They detect an increase in muscle movement and causes an increase in the individual’s heart rate in response.
Define vascular shunting
The redistribution of blood from non-working areas to working areas
When our body is at rest, where is most of our blood located?
In our digestive system
When our body is exercising, where is most of our blood?
The working muscles
What controls blood pressure and blood flow and is located in medulla oblongata?
The vasomotor centre
Define vasodilation
This is where the arteries dilate and widen to increase blood flow
Define vasoconstriction
This is where the arteries constrict to decrease blood flow
What is plasma?
The fluid part of the blood which transports the blood cells.
What is haemoglobin
A pigment found in RBC which binds with oxygen to form oxyhemoglobin.
What is myoglobin
A muscle pigment in slow-twitch muscle fibres which binds with oxygen better than haemoglobin.
What three effects causes the Bohr effect to occur when we exercise?
- An increase in CO2
- An increase in body temperature
- An increase in acidity or decrease in pH.
Briefly summarise what happens during the Bohr effect?
The oxygen disassociates with the haemoglobin to provide for the working muscles.
Define venous return
The return of blood to the right side of the heart via the vena cava.
What is starling’s law
Starling’s law states that if more blood is being pumped back to the heart, then more blood has to be pumped out which means stroke volume will increase.
What are 4 venous return mechanisms
- The skeletal muscle pump
- The respiratory pump
- Valves
- Gravity
How does the skeletal muscle pump aid venous return?
The muscles change shape when they contract and relax which causes them to press on the nearby veins and cause a pumping effect towards the heart.
How does the respiratory pump aid venous return
Pressure changes in the thoracic and abdominal cavities when muscles contract during inspiration and exhalation. These changes compress the nearby veins and assist blood return to the heart.
How do valves aid venous return
They ensure the blood flow is in the correct direction to return to the heart.
How does gravity aid venous return?
Gravity helps the blood return to the heart from the upper body
Define blood pressure
The force exerted by the blood against the blood vessel wall
Define cardiovascular drift
This is where your heart rate slowly increases after 10 minutes of steady exercise in a warm environment.
Does stroke volume increase or decrease after a steady 10 minutes of exercise in a warm environment and why does it do so?
Stroke volume progressively decreases because there is a decrease in venous return which means stroke volume will decrease (Starling’s law).
Does arterial pressure increase or decrease during steady exercise for 10 minutes in a warm environment?
Arterial pressure progressively decreases.
Does cardiac output increase or decrease during 10 minutes of steady exercise in a warm environment and why does this occur?
Cardiac output increases in an attempt to create more energy to cool the body down.
How does an athlete minimise cardiovascular drift from occurring?
Maintain high fluid consumption before and during exercise.
Define arterio - venous difference (A-VO2 diff)
This is the difference between the oxygen content of of the arterial blood arriving at the muscles and the venous blood leaving the muscles.
Is the A-VO2 diff higher or lower during rest?
The A-VO2 diff is low during rest because not much oxygen is required by the muscles.
Is the A-VO2 diff high or low during exercise?
The A-VO2 is high because the muscles require much more oxygen during exercise to produce energy.
Why will a trained individual be better at extracting and processing oxygen than an untrained individual?
This is because the trained individual’s muscle fibres will have more mitochondria and increased levels of myoglobin than the untrained individual.
