S1 Lecture 2 Flashcards
(25 cards)
What is haematocrit?
The ratio of the volume of red blood cells to total volume of blood
What are the main components of the central cardiovascular system?
Heart, 4 Chambers (LV, RV, LA, RA), Superior and Inferior Vena Cava, Aorta, Pulmonary vein and artery, Mitral, aortic, tricuspid, pulmonary valves, Pericardium, myocardium
How does left ventricular volume and stroke volume differ between power athletes and endurance athletes?
Lower in power athletes due to size of the left ventricular muscle wall, but left ventricular mass is heavier in all athletes
What type of hypertrophy occurs in endurance athletes?
Eccentric hypertrophy due to increased preload and stroke volume
What type of hypertrophy occurs in power athletes?
Concentric hypertrophy
What is included in the peripheral cardiovascular system?
Veins, Arteries, Venules, Arterioles, Capillaries
What happens to blood pH and oxygen concentration in arteries during exercise?
Blood pH decreases, oxygen concentration decreases, CO2 concentration increases, temperature increases causing vessel dilation
What role does nitric oxide play in the cardiovascular system?
Helps with vasodilation
What is myogenic contraction?
Pressure changes within vessels causing dilation at low pressure and constriction at high pressure
What occurs to blood volume during exercise?
Total volume of blood increases, with both red blood cells and plasma volume increasing fairly proportionally
What is the acute adaptation of the cardiovascular system to exercise?
To increase oxygen delivery to working muscles by increasing blood flow to muscles and reducing delivery to low activity tissues
What are the chronic adaptations of the cardiovascular system to exercise?
To deliver more oxygen to active muscle mass, more effective oxygen delivery during sub-maximal exercise, increased maximum oxygen consumption (VO2max)
What factors influence oxygen uptake and VO2max in the cardiovascular system?
Cardiac structure and function, Blood (plasma) volume, Blood flow and distribution, Oxygen Extraction (arterio-venous difference)
What does the Fick Equation represent?
VO2 = HR x SV x (a-v)O2 difference
What does the term preload refer to?
The amount of blood in the ventricle before contraction (end diastolic volume)
What is afterload?
The pressure against which the ventricle must contract
What does the Frank-Starling principle state?
The greater the stretch of the heart muscle, the greater the contraction
What happens to heart rate during sub-maximal exercise with increased stroke volume?
Decreased heart rate for the same cardiac output
What is cardiac output (Q)?
The product of heart rate and stroke volume
What is the primary mechanism for increases in blood volume in trained athletes?
Increase in plasma proteins, mainly albumin, and total body water via alterations in kidney function
What are the early changes in blood volume for trained athletes?
Plasma volume increases (10 days) then red blood cells increases (months)
What role does EPO play in the cardiovascular system?
Induces production of red blood cells
What is the significance of preload and afterload in cardiac adaptations to exercise?
They help explain how the heart adapts to the demands of exercise
What is meant by ‘athletes heart’?
Heavier heart with greater capacity to pump blood
