Chapter 1.1 Cardiovascular System Flashcards
What is the process of cardiac conduction?
- Sinoatrial node (SAN)
- Atria contract
- Atriovascular node (AVN) (0.1 second delay)
- Bundle of his
- bundle branches
- Purkinje fibres
- The ventricles contract
Why does the AVN delay the impulses sent through the heart?
Because it allows for the ventricles to fill up with blood before they contract.
define diastole
The relaxation phase of the cardiac cycle
Define systole
The contraction phase of the cardiac cycle
Define stroke volume
The volume of blood that leaves the heart during each contraction
Define health
A state of complete physical, mental and social well-being and not just the absence of illness disease or injury.
Define fitness
The ability to meet and cope with the demands of the environment.
Define physical activity
Being active and taking part in exercise
Define heart rate
Number of times the heart beats in a minute
Define Anticipatory rise
Slight increase in heart rate before activity starts due to the expectation of exercise
define Cardiac output
The amount of blood that is pumped out of the heart each minute.
Measured in L/min
Cardiac output= Stroke Volume x Heart Rate
List 3 ways exercise improves your physical health
- cardiac hypertrophy (the heart expels more blood per contraction)
- more red blood cells
- increased metabolic rate
- increased lifespan
- reduction in health risks
- lungs get stronger
Describe the pathway of blood (starting with the vena cavae)
- Vena Cavae
- Right atrium
- Tricuspid valve
- Right ventricle
- Pulmonary semilunar valve
- Pulmonary artery
- Lungs
- Pulmonary vein
- Left atrium
- Bicuspid valve
- Left ventricle
- Aortic semilunar valve
- Aorta
- Body
What blood vessel carries blood away from the heart
Away
A for Artery
What blood vessel carries blood to the heart
Veins
What is the role of valves
To prevent backflow
Define sympathetic system
A part of the autonomic nervous system that increases heart rate
Define parasympathetic system
A part of the autonomic system that decreases heart rate
What is the medulla oblongata
The most important part of the brain, it regulates processes that keep us alive such as breathing and heart rate.
Name the three receptors
Chemoreceptors
Baroreceptor
Proprioceptors
What are chemoreceptors
Detect chemical changes in the blood and increase heart rate.
Increased CO2 and increased acidity ——> increased HR
Individual benefits to a trained athlete
Increased red blood cells, haemoglobin and myoglobin cardiac hypertrophy Larger heart chambers Higher SV + lower resting HR Faster return to resting HR
What is meant by the heart being myogenic
The heart has the ability to create its own impulses without the brain
List the short term effects of exercise
Increased HR due to rising adrenaline
Increased SV due to stronger ventricular contractions
Increased cardiac output
Long term effects of exercise
Lower resting HR Cardiac hypertrophy Increased number of capillaries Increase in red blood cells Larger SV and Q
What are baroreceptors
They detect an increase in blood pressure and decrease the HR
Increase in blood pressure ——>decrease in HR
What are proprioceptors
They detect an increase in muscle movement and increase HR
Increase in muscle movement ——> increase in HR
Define ejection fraction
The percentage of blood pumped out the left ventricle per beat
During exercise why does blood redistribute around the body ?
The blood redistributes to get more blood therefore more oxygen tot the working muscles.
Blood vessels constrict around the digestive system and dilate in the working muscles
During exercise ______receptors detect chemical changes in the blood.
These receptors stimulate the vasomotor centre located in the _______
__________ which redistributes the blood through vaso________ and vaso________
Chemo, medulla oblongata, constriction, dilation
Describe the transportation of oxygen
Oxygen from the lungs —> red blood cell (haemoglobin) —> oxygen released into tissue —>oxygen stored in myoglobin —> oxygen is take to the mitochondria
Plasma = fluid part of the blood (mainly water) Haemoglobin = binds with oxygen in red blood cells Myoglobin= transports oxygen in the muscle tissues Mitochondria = part of the cell where respiration takes place
:)
What is the Bohr shift
When and increase in blood temperature, an increase in CO2 and a decrease in pH results in a reduction of the affinity of haemoglobin for oxygen.
More oxygen is released from the haemoglobin to provide more oxygen to the working muscles.
What is cardio vascular drift
This is after prolonged exercise (over 10 minutes) in a warm environment.
Water loss due to sweat reduces the amount of plasma in the blood.
This reduction in plasma means venous return and stroke volume decrease.
This results in HR increasing to keep cardiac output high.
What is venous return
The volume of blood returned to the right atrium via the vena cava
What are the three main factors influencing venous return
- The skeletal muscle pump
- The respiratory pump
- Pocket valves
What is the muscular skeletal pump
- when muscles contract and relax they put pressure against adjacent veins, squeezing blood back towards the heart
Explain the respiratory pump
When muscles contract and relax when breathing in and out pressure changes compress nearby veins assisting venous return
Explain how pocket valves assist venous return
Ensure blood only flows in one direction, they prevent back flow.
What 3 other factors aid venous return
- smooth muscles in walls of the veins that help squeeze blood back towards the heart
- gravity help venous return of blood in the upper body
- the suction pump action of the heart
What is starlings law
Venous return = stroke volume
What is the vascular shunt mechanism
The redistribution of cardiac output between rest and exercise.
Blood taken away from the digestive system and brain to provide more oxygen to the working muscles
What is arterio-venous difference
A-VO2 difference is the difference between oxygen content in the arterial blood arriving in the muscles and the venous blood leaving the muscles.
This difference is higher when exercising than at rest.
Trained performers will have a higher difference as performers can extract a greater amount of oxygen.
State and explain the two types of circulation
- Pulmonary - deoxygenated blood from the heart to the lungs and oxygenated blood from the lungs back to the heart
- Systematic - oxygenated blood to the body from the heart and deoxygenated blood from the body to the heart
How do you calculate maximum HR
220 - age
What is cardiac hypertrophy
The thickening of the muscular wall of the heart so it becomes bigger and stronger
What is bradycardia
When a performers resting HR sits below 60BPM
