Mid term

Question 1

what does parasympathetic stimulation lead to

Answer 1

hyperpolarisation of SA node cells

Question 2

which complex of lead 2 ECG includes atrial repolarisation

Answer 2

QRS complex

Question 3

the movement of which ion is responsible for the start of the slow pacemaker potential in pacemaker cells of the SA node

Answer 3

sodium

Question 4

decreased afterload would result n starling curve shifing up or down

Answer 4

upwards

Question 5

which electrical and mechanical event determine the start and end of ventricular systole

Answer 5

R-wave, and closure of the aortic valve

Question 6

compared to the systemic capillaries hydrostatic pressure is _____ in the pulmonary capillaries, leading to increased fluid _____

Answer 6

lower, reabsorption

Question 7

a given vessel has resistance of 1 (arbitary units) if the radius was to double what would the new resistance

Answer 7

1/16

Question 8

T/F
digitalis decreases the strength of contraction of the heart

Answer 8

false

Question 9

digitalis inhibits the Na+ -Ca2+ exchanger

Answer 9

false

Question 10

T/F the R=wave is observed as a large negative deflection on a lead 11 ECG trace

Answer 10

face

Question 11

T/F most of the depolarisatio nof the venticles occurs towards the apex of the heart

Answer 11

true

Question 12

during inspiration the MEA will be more horizontal

Answer 12

false

Question 13

the diaphragm is pushed into the thorac cavity during inspiration

Answer 13

false

Question 14

coronary blood flow is pulsatile and decrease during diastole

Answer 14

false

Question 15

the left and right main coronary arteries branch off from the aorta

Answer 15

true

Question 16

atrial fibrillation causes a reduction in CO during intense excerise BECAUSE a lack of atrial top-up following passive ventricular filling reduces end-diastolic volume and stroke volume

Answer 16

truw and relate

Question 17

systemic resistance is higher than pulmonary resistance BECAUSE pulmonary vessels have a larger radius and shorter total vessel length

Answer 17

both ture and relate

Question 18

what is the correct sequence for inspiration

Answer 18

diaphragm contracts, thorax expands, Pip becomes more negative (subatmospheric), Ptp increases, lung volume increases,, Palv decreases below atmospheric pressure, air flowing into lungs

Question 19

a healthy 18-year-old student is running on a treadmill. Their respiratory rate is 20 breaths/min, VT= 600ml and DSV = 160ml. what is their alveolar ventilation

Answer 19

8,800mL/min

Question 20

exercise training can improve VO2 max by

Answer 20

increasing the capacity of blood transport oxygen O2

Question 21

the process of glycolysis to generate ATP

Answer 21

converts glucose to pyruvate

Question 22

a decrease in PaO2 of up to 60mmHg will not have an immediate effect on ventilation BECAUSE central chemoreceptors do not respond to a drop in PaO2 until is falls below 40mmHg

Answer 22

both true and corelate

Question 23

acclimatisation to living in high altitude involves secretion of erthropoietin hormone to stimulate erythrocyte synthesis BECAUSE partial pressure of O2 at higher altitude is lower than at sea level

Answer 23

1st - false
2nd - true

Question 24

the Ptp increases during inspiration BECAUSE during inspiration, the Palv becomes more subatmospheric (negative

Answer 24

both true - dont cause each other

Question 25

blood vessels supplying the skeletal muscle vasocontrict during exercise BECAUSE skeletal muscle arterioles express a high desnsity of a1-adrenergic receptor

Answer 25

both false

Question 26

regional blood flow increases following local ischemia BECAUSE a reduction in perfusion pressure leads to regional vasodilation of arterioles though reactive hyperemia

Answer 26

both statements are true, and 2nd causes the first