Anatomy and physiology Flashcards
What is spatial summation
The addition of impulses recieved at different places on the neuron
Decribe how an increase in carbon dioxide in the blood during exercise would lead to an increased breathing rate (3 marks)
1) Increased blood acidity/decreased blood ph
2) detected by chemoreceptors
3) Impulse sent to medulla oblongata in respiratiry centre
3) Increased impulses sent to respiratory muscles (diaphragm/intercostals/sternocliedomastoid) to contract faster
Analyse how cardiovascular drift may result in lower levels of performance (3 marks)
1) Athletes will sweat, reducing the plasma volume of the blood
2) Blood becmes more viscous/thicker which reduced venous return
3) Due to startlings law, stroke volume and ejection fraction will decrease (as stroke volume and ejection fraction decrease, heart rate increases to maintain cardiac output)
What is ejection fraction
The percentage of blood pumped out of the left ventricle per beat
AO1 Altitude training (2 marks)
1) Training at more than 2000m/8000ft above sea level
2) Usually for at least 30 days
3) Three phases- acclimatisation, primary training, recovery
4) Partial pressure of oxygen is lower
5) Body produced EPO, higher EPO levels increase red blood cell count
Advantages of altitude training for a marathon runner
1) The marathon is a long duration, low intensity aerobic event and altitude training will increase VO2 max, allowing the athlete to perform at higher intensities for longer, resulting in a higher average speed over the duration of the race. If timed correctly, the gains in VO2 max and aerobic power could be the difference between winning and losing the race.
2) Increased myoglobin in muscle cells allows more oxygen to be stored and carried to mitochondria
3) Increased concentration of haemoglobin provides endurance athlete with increased oxygen carrying capacity.
Disadvantages of altitude training
1) Altitude sickness may occur, which may prevents the athlete training, this may mean a loss of fitness and detraining and a worse performance in the marathon, as the athlete is unable to train.
2) Furthermore, training at the same intensity as at sea level is hard so detraining and a loss of fitness may occur.
3) Altitude training is very expensive and not accesible for the majority of athletes unless elite- some of these issues can be overcome with new methodologies such as live high train low or hypoxic tents for sleeping in.
4) As benefits only last for up to 14 days, training must be performed close to the event to be effective, however travelling close to a race may have negative impacts.
Starlings law
1) Increased venous return
2)Greater diastolic filling of the heart
3)Cardiac muscle stretched
4)Greater force of contraction
5)Increased ejection fraction
What are the 3 factors affecting stroke volume
1) venous return
2)elasticity of cardiac fibres
3)contractility of cardiac tissues
Impact of venous return on stroke volume
-The return of blood to the right side of the vena cava via the veins (more blood entering the heart=more blood leaving the heart)
-Starlings law: increased venous return, greater diastolic filling of the heart, cardiac muscle stretched, greater force of contraction and ejection fraction.
Impact of elasticity of cardiac fibres on stroke volume
The more cardiac muscle fibres stretch during the diastolic filling phase of the cardiac cycle, greater the force of contraction, ejection fraction and stroke volume (starlings law)
Impact of contractility of cardiac tissue on stroke volume (myocardium)
The greater the contractility of the cardiac tissue (myocardium), the greater the force of contraction, stroke volume and cardiac output.
Stage 1 of starlings law
Increased venous return
Stage 2 of starlings law
Greater diastolic filling of the heart
Stage 3 of starlings law
Cardiac muscle stretched
Stage 4 of starlings law
greater force of contraction and increased ejection fraction, sv and cardiac output
Slow replenishment stage of EPOC/lactaid component (hours-days)
1)removal of lactic acid- oxidation into co2/water, used in muscles as energy, cori cycle, converted into protein and removed via sweat and urine
2)extra o2 needed to provide energy for maintaining high breathing and heart rate and energy for respiratory and cardiovascular muscles
3)glycogen replenishment
4)extra o2 needed to provide energy for body temperature increase
Fast stage of EPOC/alactacid component
-Uses extra o2 taken in during recovery to restore ATP and PC and resaturate myoglobin with oxygen
-takes 2-3 litres o2, complete resaturation in 3 min, 50% after 30s
How long does fast stage of EPOC take (alactacid) and how much oxygen does it use?
-takes 2-3 litres o2
-complete resaturation in 3 min
50% resaturation in 30s
What happens in fast stage of EPOC (alactacid)?
Uses extra o2 taken in during recovery to restore atp and pc and resaturate myoglobin with oxygen
Define cori cycle
The process where lactic acid is transported in the blood to the liver where it is converted into glucose and glycogen
Define EPOC
The amount of o2 consumed during recovery, above that which would have been consumed at the same time during rest
Explain how slow and fast-twitch fibres differ in structure and function
Activity used for:
Type I: Aerobic
Type IIa: long term anaerobic
Type IIx: Short term anaerobic
Contraction speed:
Type I: slow
Type IIa: fast
Type IIx: very fast
Size of motor neurone:
Type I: small
Type IIa: large
Type IIx: very large
Resistance to fatigue:
Type I: high
Type IIa: large
Type IIx: very large
Force production:
Type I: low
Type IIa: intermediate
Type IIx: high
Number of mitochondria:
Type I: High
Type IIa: High
Type IIx: low
Capillary density/oxidative capacity:
Type I: High
Type IIa: intermediate
Type IIx: low
What is Cardiac Output?
The amount of blood ejected by the heart per minute (litres/min)
Cardiac output= HR X SV
What is Stroke Volume?
The volume of blood ejected by the left ventricle per beat
What is venous return?
The volume of blood that returns to the right side of the heart
What is systolic blood pressure?
The pressure exerted against the arterial walls as blood is forcefully ejected during ventricular contraction (systole)
What is diastolic blood pressure?
Used to estimate pressure against the arterial walls when no blood is being forcefully ejected through the vessels (diastole- relaxation and filling stage)
What is ATP?
Adenosine triphosphate- a high energy compound that is the immediate energy source for muscular contractions and other energy requiring processes in the cell
What is ADP?
Adenosine triphosphate- breakdown product of ATP