Untitled spreadsheet - Sheet1 (1) Flashcards
Parasympathetic nervous system-slows down the heart (vagus nerve)
Sympathetic nervous system - speeds up the heart (impulse sent to accelator nerve)
What are the two types of nervous systems?
Stored in myoglobin (muscles)
Myoglobin has high affinity to o2 and will store o2 for mitochondria until it’s used by the muscles
O2 is carried by haemoglobin and forms oxyhemoglobin
Where is o2 stored and what does it do?
Haemoglobin can carry 4 o2 molecules
O2 is released from oxyhemoglobin due to low pressure of oxygen
Thus, tissue release causes oxyhemoglobin dissociation
What are the stages of the transportation of oxygen?
It is the shape of the blood vessel
What is vascular tone?
During rest=blood is directed towards the organs
During exercise=blood is directed towards involuntary muscles
What are the stages of vascular shunt?
Therefore ensuring muscles work aerobically
What is vascular tone and what are the stages of vascular shunt?
Difference between oxygen content of the arterio blood arriving at the muscles and the venous blood leaving the muscles
At rest a-val difference is low due to less oxygen being needed for the muscles
During exercise a-val is high as more oxygen is needed
What is arterio venous difference (a-val diff)?
Increase o2 to working muscles
Remove waste products (co2 and lactic acid)
Move blood to help regulate body temperature
Why is vascular shunt important?
Is the amount of blood that returns back to the heart. 70% of total volume of blood is contained in the veins at rest
What is venous return?
Diastole-when the heart relaxes and fills with blood
Systole-when the chambers contract and empty,when blood ejects from the heart
Cardiac cycle-one complete cycle of diastole and systole
Define diastole,systole and cardiac cycle
Skeletal muscle pump-muscles contract this squeezes together the veins acting as a pump
Respiratory pump-muscles contract when breathing,the changes in pressure assist blood to the heart
Pocket valves-blood only flows in one direction, the presence of valves ensure this happens as valves close to prevent blood going the opposite way
What are the venous return mechanisms?
High blood pressure,high cholesterol,lack of exercise,smoking Angina - When there is an atheroma build up and is broken off in the arteries
What are the causes of heart disease, the pain in the heart and why does it occur?
After 10 minutes of steady state exercise,heart rate increases
Plasma is lost during exercise so blood becomes more viscous
Thus,blood is more difficult to pump
What is cardiovascular drift?
When adrenaline is relaxed before exercise
What is anticipatory rise?
During exercise curve shift right (Bohrs shift)
Increase in co2 and temperature
Allowing o2 to dissociate from haemoglobin easier
steps for the oxyhemoglobin dissociation curve?
LdL (low density lipoproteins)- classed as bad cholesterol due to cholesterol getting into tissues HDL (high density lipoproteins)-classes as good cholesterol due to cholesterol being transported to the liver to be broken down
What are the types of cholesterol
Regular physical activity reduces LDL and increases HDL
how do we change cholesterol levels?
Commonly known as coronary heart disease
Occurs when coronary arteries Crome blocked with a build up of fatty deposits and is known as atherosclerosis
What is heart disease commonly known as and why does it occur?
Bradycardia is a low resting heat rate
What is bradycardia?
Cardiac output=stroke volume x heart rate or volume of blood pumped out by the heart per minute
What is cardiac output?
Sa node, atrial systole, AV node, bundle of his, purkinje fibres, ventricular systole
What are the steps for cardiac conduction system?
V-rec venous return,elasticity and contractility
Describe starlings law and what is the acronym?
increased venous return, greater diastolic filling, cardiac muscle stretched (elasticity), more forceful contraction (contractility), increased ejection fraction (amount of blood ejected out the ventricle)
How does the cardiac conduction system work?
Sa node generates an electrical impulse and is fired through atria walls like a wave of excitation, Atria contract,thus forcing blood through the valves, Atrioventricular node receives receives signals and delays for approx 0.1 seconds and then releases a signal to the bundle of his, signal then travels down the bundle of his, the signal is split into 2 and is sent to both ventricles, the purkinje fibres then distribute the impulse through the ventricle walls fussing them to contract aka ventricular systole, Right atrium-tricuspid valve-right ventricle-pulmonary artery-lungs-pulmonary vein-left atrium-bicuspid valve-left ventricle-aorta-blood pumped around/vena cava
What are the steps of blood being pumped around the body?
The amount of blood ejected by the heart in each contraction: yes due to starlings law
Define stroke volume and does it increase in exercise and why?
A stroke occurs when the blood supply to part of the brain is cut off p, thus causing damage to brain cells; Ischaemic-blood clot and Haemorgic-weakened blood vessel
What is a stroke and what are the two types?
