Blood Transport System Flashcards
Describe how running affects the venous return mechanism.
Venous return increases (Skeletal pump) – increased muscle contractions compress veins and push blood towards heart; One way valves in veins / to prevent backflow; (Respiratory pump) – greater breathing movements alter pressure in thorax compresses veins – assist flow back to heart; Running – heart beating faster – suction pump of heart.
Explain the causes of the Bohr shift and how it increases oxygen delivery to the working muscles.
Exercise increases temperature; Exercise causes increased CO2 / acidity in blood / lower pH / increased H ion concentration; Curve shifts to right; More oxygen disassociates from haemoglobin / reduced affinity for oxygen;
Explain how redistribution of blood occurs during exercise.
Increase in CO2 levels / acidity / decrease in O2 levels / pH / chemoreceptors (MUST EXPLAIN TERMS) Movement of joints / tendons / mechanoreceptors / proprioceptors Vasomotor centre / medulla Autonomic / sympathetic nervous system / (nor) adrenaline Pre-capillary sphincters / rings of circular / smooth muscle Vasodilation to areas needing blood / muscles Vasoconstriction of areas not needing so much blood / kidneys / liver / gut
Explain why blood flow to the brain remains the same during rest and during maximum effort.
Brain function maintained during exercise Oxygen / nutrients required
Explain why performers should not eat immediately before exercise.
During exercise, less blood goes to the gut / change from 1250 cm3 to 375 cm3 (Credit use of table to suggest reduced gut blood) But, blood / oxygen needed in gut for digestion of food (‘Unable to digest food’ is incorrect) Less blood / oxygen available to muscles
Describe two characteristics of veins which assist the transport of blood.
Thinner muscle / elastic tissue layer Valves Wider lumen / diameter Blood at low pressure (Not just thinner)
Where is myoglobin found in the body and what is its role during exercise?
In muscle. (Required term is muscle) Stores / supplies / carries oxygen.
State three characteristics or functions of arteries.
Thick, Elastic walls.
(Small) lumen.
(Smooth) muscle layer.
Required terms
Carrying blood away from the heart / to tissues / muscles.
‘Carry oxygenated blood’ is incorrect because not completely true,
but ‘carry oxygenated blood away’ is correct because direction
given.
Cushion and smooth out / recoil / pulse / withstand pumping action / pressure
/ velocity from heart.
During a game, a player’s arterio-venous oxygen difference (a-vO2 diff) will increase.
What is the significance of this increase in a-vO2 diff to the player?
A Difference between oxygen content of arterial and venous blood.
B More oxygen is needed / extracted by the muscles.
Oxygen is key term
C Used / needed for energy / ATP production.
Idea of role of oxygen
D Endurance / stamina / aerobic exercise.
Idea of what type of exercise
E Leads to improved performance.
Must be linked to C / D
F Increased oxygen diffusion at lungs / alveoli / muscle.
G More oxygen in blood
H More CO2 in blood / produced.
(G and H Must be linked to F)
During a game, the blood pressure of a player increases.
What factors determine the ‘blood pressure’ in arteries?
Contraction of the heart / stroke volume / ejection fraction / heart rate
Idea of contraction / beating of heart.
Increased blood flow / cardiac output / Q
Idea is more blood = more pressure.
(Peripheral) resistance / friction / elasticity of walls
Thickness of blood.
Blood viscosity / sweating / loss of fluid
Accept size.
Blood vessel length / distance from the heart
Accept alternatives, but NOT injury.
Blood vessel diameter / size / vasoconstriction / vasodilation / cross
sectional area / lumen size.
Health factor / atherosclerosis / diet / stress / drugs / hereditary.
Age / level of fitness / intensity of exercise.
Running helps the ‘venous return’ mechanism.
Explain how the venous return mechanism works.
Muscle / skeletal pump / respiratory pump / suction pump;
One-way / pocket valves in veins / give direction.
must link valves with location or direction
Contraction of leg muscles compresses veins;
Breathing mechanism / inspiration increases pressure compresses veins;
Suction pressure of heart / heart draws up blood.
Explain why aerobic training improves the performer’s ability to transport oxygen.
More blood volume / haemoglobin / Hb / red blood cells;
Increased a-VO2 diff / more oxygen extracted by muscles;
Increased capilliarisation / more capillaries.
State two ways in which carbon dioxide is transported by the blood.
As bicarbonate / hydrogen carbonate ions / carbonic acid;
Dissolved in plasma;
Combined / attached with plasma proteins / haemoglobin / forms carbaminohaemoglobin.
Explain how oxygen is taken up by haemoglobin from the lungs and released at the muscle
site.
Forms oxyhaemoglobin / Hb O2;
At lungs – high partial pressure of O2 / blood – low partial pressure of O2;
Haemoglobin becomes saturated;
At muscles – low partial pressure of Oxygen / O2 / blood – high partial pressure of O2;
Hence oxygen dissociates from haemoglobin;
Mention of myoglobin.
How does running assist the venous return mechanism?
Action of muscles contracting compresses veins.
Veins have one way valves / to prevent backflow.
Change in pressure / size of chest.
Blood pushed towards heart.
