Cardiac Muscle Flashcards Preview

Fundies First Module--First Exam > Cardiac Muscle > Flashcards

Flashcards in Cardiac Muscle Deck (27):
1

cardiac muscle has smaller

sarcomere units ( like skeletal muscle)

2

does cardiac muscle branch

yes--unlike skeletal

3

junction between cardiac cells

intercalated discs (unlike skeletal)

4

intercalated disks for

fast communication between cells--gap junctions--heart contraction all-or-nothing
Desmosomes--cell body for adhesion

5

membrane surrounding cardiac muscle cells

sarcolema

6

higher demand than skeletal thus

more T tubules, ATP, sarcoplasmic reticulum, slow Ca gates (allows for continuous contractal state)

7

CCB

calcium channel blockers--decreases FORCE of contraction of heart

8

arythmias happen during

end of absolute refractory period

9

Ventricular Function measured by

Frank-Starling Curve-- length-tension curve for heart (although not same as skeletal muscle shortening)

10

which muscle type has more available Ca

cardiac--for sustained contractability

11

heart failure means

lower stroke volume (amount of blood heart pushes out)

12

volume of blood in heart after filling

end-diastolic volume

13

beta-blocker

negative inotrope

14

stroke volume at aorta

Afterload
X-axis: stroke volume
Y-axis: outflow resistance (afterload)
If resistance is high--output will be low

15

enlargement of heart walls (cardiomyopathy)

hypertrophy--usually most noticeable at apex--will decrease volume able to enter ventricle

16

hypertrophic heart complications

stiffening of wall
decreased volume

17

myocardial labs

1. cardiac troponins: released into blood when heart damaged i.e MI
2. Serial Troponins taken--series over time

18

Cell structure specialized for cell-cell adhesion btwn cardiac muscle cells

Desmosome--

19

Agent that alters the force of energy of cardiac muscle contraction

Inotrope--negative inotropic agents weaken force of muscle contraction

20

Increase velocity of contraction and SV

Positive inotropes

21

Decrease velocity of contraction and SV

Negative inotropes

22

Amount of resistance to ejection of blood from LV

Afterload

23

Muscle with no troponin

Smooth muscle

24

Less myosin

Smooth muscle-- calmodulin

25

<50% saturation ______ ________

Decreases contractility

26

After load-- resistance

Lower pressure >faster contraction
Heavier afterload>slower contraction

27

Cardiac frank- starling curve relates

Stroke volume w/ ventricular filling--related to proper myosin/actin position at preload