cardiac innervation

Question 1

name two types of cardiac cells involved in contraction and relaxation

Answer 1

• muscle cells

- conduction cells

Question 2

what are muscle and conduction cells joined together by

Answer 2

gap junctions

Question 3

what allows passage of electrical impulse from one cell to the next

Answer 3

gap junctions

Question 4

four types of cardiac cells

Answer 4

• myocardial
• conduction
• avascular valvular tissue
• endocardial cells

Question 5

which cells are working cells that perform contraction

Answer 5

myocardial/contractile cells

Question 6

what are myocardial (contractile) cells made up of

Answer 6

myofibrils

Question 7

whats a sarcomere

Answer 7

segment of myofirbil

Question 8

what do myofibrils contain (2 things)`

Answer 8

actin and myosin

Question 9

during contraction, what do actin and myosin do?

Answer 9

slide together nd overlap to a greater degree

Question 10

what do actin and myosin do during relaxation

Answer 10

slide apart

Question 11

what does an increase in preload do to actin and myosin

Answer 11

stretches apart / force of contraction increased

Question 12

how does an increase in after load affect actin and myosin

Answer 12

contraction decreases. less overlapping

Question 13

ions entering the cell through channels in membrane is called

Answer 13

influx

Question 14

opposite to efflux

Answer 14

influx

Question 15

the ability for a cell to produce their own impulse

Answer 15

automaticity

Question 16

the ability of a cell to accept impulse and transmit it to other surrounding cells

Answer 16

excitability

Question 17

the ability of a cell to respond to a stimulus

Answer 17

refractory

Question 18

define excitation coupling

Answer 18

series of events that connects the electrical stimulation to the subsequent mechanical event of contraction

Question 19

describe action potential phase 0:depolarization

Answer 19

• cell stimulated and prepared to contract
• cell fires from threshold to maximal positive state
• refractory to all stimulus

Question 20

describe action potential phase 1: early repolarization

Answer 20

• cell moves to a slightly less positive state. still unable to accept stimulus.

Question 21

describe phase 2 plateau stage

Answer 21

• excitation coupling actin and myosin reacting to electrical signal leading to contraction
• contraction phase of cell
• CALCIUM RUSHES INTO CELL WHILE POTASSIUM LEAVES THE CELL

Question 22

describe stage 3 repolarization

Answer 22

• post contraction where cell returns to resting state. Downslope on action potential. potassium leaves the cell

Question 23

phase 4 resting state

Answer 23

upward slope determines ow fast the automaticity rate is. Steep phase 4 = fast intrinsic rate, flat phase 4 means slow