1.1 CardioVascular System Flashcards
What does health and fitness mean
Health - state of complete physical, mental and social well-being not just absence of disease.
Fitness- ability to meet and cope with the demands of the environment.
What are the four chambers of the heart
Left atrium
Right atrium
Left ventricle
Right ventricle
What is the cardiac conduction system
And what does myogenic mean
System that causes your heart to beat
Heart is myogenic- produces its own pulse
Outline the cardiac conduction system
SAN
Atrial systole
Avn
Bundle of his
Bundle branches
purkinje fibres
Ventricular systole
What does diastole mean
The heart relaxes and fills up with blood
Increasing pressure in chamber
What does systole mean
Atrial systole
Ventricular systole
Heart contracts
Atrial systole - atriums contract forcing blood into ventricles
Ventricular systole- ventricles contract
Pathway of the blood
Vena cava
Right atrium
Tricuspid valve
Right ventricle
Pulmonary semi lunar valve
Pulmonary artery
Lungs
Pulmonary vein
Left atrium
Bicuspid valve
Left ventrical
Aortic semi lunar
Aorta
Body
Nervous systems affecting heart rate
Sympathetic NS- increase HR for exercuse
Parasympathetic NS- returns Hr to resting levels after exercise
What are the neaural control mechanisms for HR
Chemoreceptors
Baroreceptors
Proprioceptors
What do these receptors do
chemoreceptors
Baroreceptors
Proprioceptors
Chemoreceptors- Detect increase in CO2 —> to increase HR
Baroreceptors-Detect change in blood pressure —> decrease HR
Proprioceptors- detect increase in muscle movement —> increase HR
What is stroke volume
Average stroke volume is…
Volume of blood pumped out the heart ventricles per beat
70ml
What is cardiac output
Volume of blood pumped out the left ventrical per minute
What is HR
Number of beats per minute
Average- 70
Equation for cardiac output
Cardiac output (l/m) = stroke volume (l) x HR (b/pm)
What does cardiac hypertrophy mean
What does bradycardia mean
Cardiac hypertrophy- Thickening of the muscular wall of the heart so it becomes bigger and stronger
Bradycardia- decrease in resting HR below 60 bpm
What is anticipatory rise
Slight increase in Hr before exercise due to expectation of exercise
Happens due to adrenaline
Short term effects of exercise
Increase HR due to anticipatory rise
Increase stroke volume due to stronger ventricular contractions
Increase cardiac output
Long term effects of exercise
-decrease resting Hr bradycardia
-cardiac hypertrophy - bump greater volume of blood
-increase number of capillaries
-increase number of red blood cells = more oxygen
-lungs become stronger
-reduction in health risks eg cardiovascular disease, diabetes
Why does blood redistribute around the body during exercise
To get more blood (oxygen) to the working muscles to provide more energy
What is the Bohr shift
During exercise the curve shifts to the right, what is this ?
This is called the Bohr shift
It’s caused by an increase in CO2, increase blood temp and increase in blood acidity.
More oxygen is being released from the haemoglobin Important for exercise as it provides more oxygen to the working muscles to provide energy
What is venous return
Return of blood to the right side of the heart via the vena cava
What is stirlings law
Venous return = stroke volume
Whatever gets pumped into the heart gets pumped out the heart
What are the 6 venous return mechanisms
The skeletal muscle pump
The reporatory pump
Pocket valves
Smooth muscle in walls of viens- helps squeez blood back to heart
Gravity -helps blood return to the heart from upper body
Suction pump action of the heart
What does the skeletal pump do
When muscles relax and contract they press on nearby veins causing a pumping effect squeezing blood towards the heart
What does the respiratory pump do
When we breath our chest and stomach cavity’s change size compressing nearby veins pushing blood back to the heart
What do pocket valves do
Prevent the back-flow of blood making it flow in one direction towards the heart
What is blood pressure and how does it change during exercise
Blood pressure- the force exerted by the blood against the blood vessel walls
During exercise blood pressure increases due to increase in cardiac output meaning more blood in flowing through the body As working muscles need more oxygen.
What is cardiovascular drift
Happens during prolonged exercise (10 mins) in a warm environment where cardiac output increases.
Stroke volume decreases due to Water loss from sweating reding the amount of plasma in the blood
This leads to a decrease in stroke volume as HR has increased so not as much blood needs to be pushed out per contraction.
What is A-Vo2 difference
Difference between oxygen content in atrial blood and venous blood
Atrial blood- arriving at the muscles
Venous blood- leaving the muscles
Why is a trained athletes A-vo2 higher than an untrained person
And why does A-vo2 increase during matches
Higher A-Vo2 due to more capillaries, higher stricken volume, cardiac hypertrophy meaning more blood getting to working muscles so more myoglobin and more 02
Increases during exercise as you need more oxygen to your working muscles les to provide yourself more energy and delay the effects of fatigue,
What do veins do and characteristics
Carry blood towards the heart
No stretch
Thin layer of smooth muscle
Large lumen
Pocket valves
Why are cool downs important
-prevent blood pooling
-keep muscles contracting- skeletal pump
-keep breathing rate up -respiratory pump
^ maintaining venous return - delays doms
Explain how redistribution of blood is achieved during exercise
Gut and muscles
Less blood flow in the stomach at exercise as message is sent from vaso motor centre to atries to vaso constrict at the gut and vaso dilate at muscles so more oxygen can get to the working muscles providing them with more energy.
What is vascular shunt mechanism
The redirecting of blood flow to areas where its most needed.
What is myoglobin
Oxygen stored in muscle fibres
How do you calculate maximum Hr
220- age
Why does blood flow to the brain remain the same
Why does more blood go to the skin during exerciise
To maintain brain functioning as the brain needs oxygen for energy.
More blood goes to the skin because the energy is needed to cool the body down
