Lecture 8 revision questions

Question 1

describe the changes in the cardiovascular system from the foetus to adulthood?

Answer 1

oxygen is supplied by the mother to the foetus therefore the lungs are not needed. the foetus has ducts which allow for the blood to bypass the lungs - the foramen ovale which connects the left and right artia and the ductus arteriosus which connects the aorta and pulmonary artery

within 30min of the baby’s first breath the ductus arteriosus and the foramen ovale will close due to the increase pressure on the left side and a decrease pressure on the right side

Question 2

Describe the structural differences of the foetal heart that allow it to direct oxygenated blood around the body

Answer 2

• Shunts (foramen ovale and ductus arteriosus) allow most of the blood to bypass the lungs

Question 3

how does the left ventricle change with growth?

Answer 3

• increases slower than body mass, closer to the same rate as fat free mass

Question 4

is there a difference in the male and female heart? if so when and why does this occur?

Answer 4

• females have a higher bpm (males= 72bpm, females= 76bpm)

- males have a higher systolic blood pressure than females

Question 5

What is “Q” a function of?

Answer 5

Cardiac output

Question 6

How does the heart function change with ageing?

Answer 6

• thickening of blood vessels and left ventricle
• increased stiffness in the aorta
• max HR decreases 10bpm per decade

Question 7

Calculate the maximum predicted heart rate for 45yr old individual

Answer 7

healthy adult = MHR = 220 - age

MHR (>40) = 208 - 0.7 x age
= 208 - 0.7 x 45 = 176.5

Question 8

why is determining the effects of ageing on CV function said to be difficult?

Answer 8

since physical activity tends to decline substantially as we age, distinguishing between the effects of ageing and those of reduced physical activity is difficult when studying lifelong changes in physiological function