Cardiovascular System Flashcards
How many chambers are there in the heart?
4 - R/L ventricle and R/L atria
Which chambers of the heart are bigger? Which has more pressure and thicker walls?
Ventricles are bigger and have thicker walls and more pressure to pump blood around the whole body
What are the main 4 blood vessels in the heart? What kind of blood do they carry and where do they lead?
Vena cava - deoxygenated blood to right atrium
Pulmonary vein - oxygenated blood to left atrium
Pulmonary artery - leaves right ventricle with deoxygenated blood to lungs
Aorta - leaves left ventricle with oxygenated blood to the body
What is the cardiac conduction system?
The way the heart contracts - beat starts in the heart itself so is myogenic
What are the 6 parts of the cardiac conduction system?
1 - sinoatrial node (SAN) 2 - down atrium walls 3 - atrioventricular node (AVN) 4 - bundle of his 5 - bundle branches 6 - purkyne fibres 7 - ventricles contract
What’s is anaerobic exercise? Give a sporting example
Work that doesn’t use oxygen
E.g. 100m sprint
What is aerobic exercise? Give a sporting example
Work with oxygen
E.g. 10,000m run, marathon, football midfielder
Why is the heart referred to as a dual pump system?
Because it has 2 desperate pumps working simultaneously - the right side pumps deoxygenated blood to the lungs and the left side pumps oxygenated blood to the body
Remember left and right side are reversed!
What is the first stage of the cardiac cycle?
Diastole
Relaxation/filling stage lasting 0.5 secs
Deoxygenated blood enters right atrium from vena cava
Oxygenated blood enters left atrium from pulmonary veins
Rising blood pressure forces blood into ventricles through tricuspid and bicuspid valves
What is the second stage of the cardiac cycle?
Atrial systole
Contraction of the atria to force blood into ventricles
What is the third stage of the cardiac cycle?
Ventricular systole
Contraction of ventricles
Blood is forces out to the body and the lungs
Bicuspid and tricuspid valves remain shut to prevent blood backflow
What is the term for when the contraction of the heart is not synchronised?
Fibrillation
What is the sympathetic system?
Part of the nervous system that speeds up heart rate
What is the parasympathetic system?
Part of the autonomic nervous system that decreases heart rate
What is the medulla oblongata?
Most important part of the brain that regulates processes that keep us alive
E.g. breathing and heart beat
What 2 parts is the nervous system made of?
1 - CNS (brain and spinal chord)
2 - peripheral nervous system - nerve impulses that transmit info to/from CNS
What is the cardiac control centre stimulated by?
Chemoreceptors, baroreceptors and proprioreceptors
What are chemoreceptors?
Tiny structures in cartoid arteries that detect changes in blood acidity due to CO2 concentration
What are baroreceptors?
Sensors in tissue in aortic arch and vessels that detect changes in blood pressure
What are proprioreceptors?
Nerve endings in muscles, tendons and joins that detect changes in muscle movement
What is the technical name for coronary heart disease? What is the name for the fatty deposit that builds up?
Atherosclerosis
Atheroma
What increases the risk of atherosclerosis?
High blood pressure
High level of cholesterol
Lack of exercise
Smoking
What is adrenaline?
A stress hormone released by the sympathetic nervous system by during exercise. It increases cardiac output
What is acetylcholine?
Stress hormone released by parasympathetic nervous system - decreases cardiac output
What is venus return?
Volume of blood returning to heart from the veins
What is stroke volume?
Amount of blood pumped out of the heart per stroke
What is cardiac output?
The amount of blood pumped out of the heart per minute
What is starling’s law?
Increased venous return ➡️ greater diastolic filling of the heart ➡️ cardiac muscle stretched ➡️ more force of contraction ➡️ increased ejection fraction
What is ejection fraction?
Percentage of blood pumped out the left ventricle per beat
What is it called when the heart becomes bigger and stronger?
Cardiac hypertrophy
What is cardiovascular drift?
A progressive decrease in stroke volume and arterial blood pressure combined with a progressive rise in heart rate. It occurs during prolonged exercise
What % of oxygen binds to haemoglobin? How many molecules of oxygen bind to haemoglobin?
1 - 97%
2 - 4 molecules
When/why is oxygen released? What happens to CO2?
Oxygen is released at tissues due to low pressure of oxygen. CO2 diffuses opposite direction due to low pressure of CO2 in blood
What is the release of oxygen from haemoglobin called?
Oxyhaemoglobin dissociation
How is oxygen stored in muscles?
Myoglobin
What happens to the oxyhaemoglobin dissociation curve during exercise? What is this called?
The whole curve shifts to the right. This is called Bohr shirt
What are the three venous return mechanisms? What do they do?
1 - skeletal muscle pump
2 - the respiratory pump
3 - pocket valves
They help venous return during exercise
How does the skeletal muscle pump increase venous return?
Muscles around veins contract and press on the veins, , causing a pumping effect an squeezing blood towards the heart
How does the respiratory pump increase venous return?
During breathing pressure changes occur in the chest and stomach. These changes compress nearby veins and assist blood returning to the heart
How do the pocket valves increase venous return?
It is important blood does not flow backwards, so the valves snap shut to prevent blood backflow
What is the term to describe a heart rate that is below 60 beats per minute?
Bradycardia
Why may trained and untrained performers have similar cardiac outputs in certain activities?
Trained - high SV low heart rate Untrained - low SV high heart rate Balances out Different physiques Not specialised at activity
What causes Bohr’s shift?
Increase in blood temperature
Partial pressure of CO2 increases
Decrease in pH
Demand for oxygen increased so dissociates faster
What do you need to write about in a long answer question?
A01 - knowledge (what the things in the question are)
A02 - application (how it helps the performer)
A02 - how it helps performance
