Force generation by the heart

Question 1

cardiac muscle

Answer 1

striated due to regular arrangement of contractile protein

Question 2

what do desmosomes ensure

Answer 2

that the tension develope by one cell is transmitted to the next

Question 3

contractile units of muscle

Answer 3

myofibrils

Question 4

actin

Answer 4

thin filament

Question 5

myocin

Answer 5

thick filaments

Question 6

what are actin and myocin arranged into

Answer 6

sarcomeres

Question 7

how is muscle tension produced

Answer 7

by sliding of actin filaments on myocin filaments

Question 8

where is ca+ released from

Answer 8

sracoplasmic reticulum

Question 9

cross bridge binding

Answer 9

when the muscle fiber is excited ca+ binds with troponin pulling troponin tropomysoin complex aside to ezpose cross brudge binding site

Question 10

what does the long refractpry period prevent

Answer 10

generation of tetanic contraction

Question 11

refractory period

Answer 11

period following an action potential in which it isnt possible to produce another ap

Question 12

stroke volume

Answer 12

the volume of blood ejected by each ventricle per heartbeat

Question 13

calc for stroke volume

Answer 13

EDV-ESV

Question 14

Intrinsic control of stroke volume

Answer 14

changes are broiught about by changes in the diastolic length/ diastolic stretch of myocardial fibers

Question 15

end diastolic volume

Answer 15

volume of blood in each ventricle at the end of diastole

Question 16

what does the end diastolic volume dtermine

Answer 16

preload

Question 17

what is the end diastolci volume determined by

Answer 17

venous return to the heart

Question 18

frank starling curve

Answer 18

states that the more the ventricle is filled with blood during diastole the greater the volume of ejected blood will be during the resulting systolic contraction

Question 19

skeletal optimal fibre length

Answer 19

atresting

Question 20

cardioac muscle optimal

Answer 20

stretching

Question 21

increased afterload

Answer 21

eventually the ventricular msucle mass increases to overcome resistance - hypertension

Question 22

afterload

Answer 22

resistance into which the heart is pumping

Question 23

positive inotropic effect

Answer 23

stimulation of sympathetic nerves increase the force of contraction;noradrenaline

Question 24

effect of sympathetic nerve stimulation on frank starling curv

Answer 24

shifts to left

Question 25

how does heart failure affect frankstarling

Answer 25

shifts to right

Question 26

cardiac output

Answer 26

volume of blood pumoed by each ventricle per minute

Question 27

calc for co

Answer 27

sv x hr

Question 28

What feature of cardiac myocytes allows for the transmission of ions between adjacent cells

Answer 28

intercalated discs