Module 8 ML-1

Question 1

Atrium

Answer 1

-top chambers of the heart, they are small in size and there is a left and a right

Question 2

Ventricles

Answer 2

-bottom chambers of the heart, they are large and there is a left and a right

Question 3

Myocardium

Answer 3

cardiac muscle cells

Question 4

Are there striations in cardiac muscle?

Answer 4

Yes, they come from the regular arrangement of the myofilamemnts

Question 5

True or false; cardiac cells are branched on the ends

Answer 5

True

Question 6

What provides the mechanical and electrical connections between cardiac muscle cells

Answer 6

intercalated disks

Question 7

What provides the structural support

Answer 7

Desmosomes and intercalated disks

Question 8

The cardiac muscle is what?

Answer 8

A functional syncytium

Question 9

Why is the resting membrane potential very negative at -89

Answer 9

Lots of potassium leak channels

Question 10

What are the 4 steps of an AP in cardiac muscle

Answer 10

1. current enters from neighboring cells through gap junctions
2. rapid opening of voltage gated sodium channels are responisble for the rapid depolarization phase
3. Plateu occurs
4. slow opening of voltage gated potassium channels are responsible for the repolarization phase

Question 11

What causes the plateu during the repolarization

Answer 11

due to slow but prolonged opening of voltage gated calcium channels; L type channels

Question 12

L type channles are the same as what?

Answer 12

DHPRs and act as functional calcium channels

Question 13

Prolonged refractory period prevents what in cardiac muslce

Answer 13

tetanus

Question 14

Why can you not summate force in cardiac?

Answer 14

this allows time for the ventricles to relax and fill with blood prior to the next heartbeat

Question 15

What muscle types contain myosin thick filaments and actin thin filaments

Answer 15

Sk, Sm, Card

Question 16

What muscle types jave troponin and tropomyosin?

Answer 16

Sk and Card

Question 17

What muscle types are small and uninucleated?

Answer 17

Sm and Card

Question 18

What muscle types are arranged into layers and surround hallow cavities

Answer 18

Sm and Card

Question 19

What muscle types have the same 4 steps of the cross bridge cycle

Answer 19

Sk, Sm, and Card

Question 20

What muscle types have sliding filaments mechanisms of contraction

Answer 20

Sk, Sm, and Card

Question 21

What muscle types have ATP powers that generate force

Answer 21

Sk, Sm, and Card

Question 22

What muscle types have elevated cytosolic calcium which initiates contraction

Answer 22

Sk, Sm, and Card