cardiac mechanisms

Question 1

^ preload causes what changes to PV loop

Answer 1

^ EDV, ^ SV
widens loop to R

Question 2

^ preload _____ sarcomere, which _____

Answer 2

lengthens sarcomere
= pos. inotropy

Question 3

^ afterload causes what changes to PV loop

Answer 3

v SV
taller & narrow

Question 4

(+) inotropy causes what changes to PV loop

Answer 4

v ESV, ^ SV
widens loop to L & steeper ESPVR slope

Question 5

determinants of CO

Answer 5

-HR (regulated by SNS / PNS)
-preload (EDV)
-contractility (inotropy)
-afterload

Question 6

contractiliy & afterload change _____

Answer 6

ESV

Question 7

preload changes _____

Answer 7

EDV

Question 8

what determinants of CO regulate SV

Answer 8

preload
contractility
afterload

Question 9

factors that ^ preload (EDV)

Answer 9

^ atrial contractility
^ ventricular compliance
^ central venous pressure
^ aortic pressure
v HR

Question 10

mechanism for v HR causing ^ preload

Answer 10

v HR = ^ filling time = ^ EDV

Question 11

mechanism for ^ aortic pressure causing ^ preload

Answer 11

^ aortic pressure = v SV = v EF = ^ ESV = ^ EDV

Question 12

mechanism for ^ central venous pressure causing ^ preload

Answer 12

v venous comliance & ^ venous return

^ central venous pressure

Question 13

mechanism for ^ ventricular compliance causing ^ preload

Answer 13

more stretch = more volume = ^ EDV

Question 14

mechanism for ^ atrial contractility causing ^ preload

Answer 14

^ filling from atria = ^ EDV