Exam 4 - CARDIAC

Question 1

MAP reflects what exactly ?

Answer 1

Left Ventricular Afterload

Question 2

Where are the gap junctions located in the heart muscle ?

Answer 2

at the intercalated discs

Question 3

What are the high surface areas of the cardiac muscle ?

Answer 3

Intercalated disc

Question 4

Where are intercalated disc found ?

Answer 4

ONLY in the heart

Question 5

what is the pattern of the cardiac muscle?

Answer 5

striated muscle - due to lover laying of actin and myosin

Question 6

How many nuclei do cardiac cells have ?

Answer 6

ONE

Question 7

What type of muscle is mutli nucliated ?

Answer 7

ONLY skeletal muscle

Question 8

Sarcomeres of cardiac muscle is similar to skeletal sarcomere ? T o F ?

Answer 8

TRUE

look exactly the same as skeletal muscle

Question 9

Natural STEM cells do what in our body ?

Answer 9

replace cardiac muscle cells but very slowly

Question 10

Where are fibroblast found ?

Answer 10

In the heart

Question 11

What do fibroblast do in the heart ?

Answer 11

Fibroblast lay down scar tissue anywhere that the stem cells cannot fix

Question 12

What disease can fibroblast repair lead to ?

Answer 12

CHF

laying down of scar tissue unnecessarily

Question 13

What drug can slow down Fibroblast and why would we want it to ?

Answer 13

ACEi - block growth hormone factor of renin angiotensin system

Fibroblast does not conduct like normal cardiac tissue/muscle.

Question 14

What drugs do pregnant people not want to be around that helps with heart failure ?

Answer 14

ACE or ARB’s

Question 15

What word describes the layers and directions of the heart muscle ?

Answer 15

multi-layered SYNCYTIAL

Question 16

How are the layers of the heart muscle layered?

Answer 16

two distinct layers that move in two opposite directions

Question 17

Whats included in the “top half” of the heart ?

Answer 17

Left and Right ATRIA

Question 18

Whats included in the “lower half” of the heart ?

Answer 18

Left and Right VENTRICLES

Question 19

Different types of the cells in the heart ?

Answer 19

Muscle tissue

Question 20

How does muscle tissue produce alot of force ?

Answer 20

achieves force by having lots of myofibrils within each muscle cell

Question 21

How are myofibrils arranged in the heart ?

Answer 21

stacked or laid on top of each other for the length of the cell which increases the force

Question 22

What makes the conduction tissue of the cardiac muscle different from other tissue?

Answer 22

there is less “stuff” inside the conduction tissue, which increases the force/conduction of the cardiac tissue

Question 23

Where is the endocardium ??

Answer 23

Deep 1cell-layer thick endotheiliel muscle the heart

Question 24

What is the myocardium of the heart ?

Answer 24

Bulk of the muscle wall

Question 25

Where is the epicardium ?

Answer 25

Outer layer of the heart most superficial layer

Question 26

Where do most of the major blood vessels sit on the heart ?

Answer 26

The EPICARDIUM

Question 27

What does the Pericardium consist of ?

Answer 27

Connective tissue of the sac of the heart Epicardium Pericardial Space Parietal Pericardium - Inner layer Fibrous Pericardium - outer STIFF layer

Question 28

What layer sits just outside the Epicardium ?

Answer 28

Pericardial Space

Question 29

What does the pericardial space consist of ?

Answer 29

thin layer of fluid and mucus

Question 30

what does the pericardial space serve for ?

Answer 30

allows for the movement of the heart without pain -lubricates the heart muscles at they move

Question 31

What can increase friction in the heart ?

Answer 31

loss of fluid or inflammation of the pericardial space

Question 32

Which part of the heart is stretchy ?

Answer 32

Parietal Pericardium

Question 33

Which part of the heart is leathery and difficult to stretch ?

Answer 33

Fibrous pericardium

Question 34

Subendocardium means what ?

Answer 34

super deep muscle layer in the heart wall

Question 35

Where would an MI likely occur?

Answer 35

deep in the subendocardium layer

Question 36

Where are our pressure the highest in the heart ?

Answer 36

subendocardium - deep in the heart

Question 37

What increases the liklihood of ischemia in the heart ?

Answer 37

clogged vessels and high wall pressure

Question 38

How does the orientation of cardiac sarcomere differ from other sarcomeres ?

Answer 38

Cardiac sarcomere is not relaxed to optimum degree no H band due to actin and myosin filaments slightly overlap (UNDER-STRETCHED when relaxed )

Question 39

Purkinje Fibers serve what purpose in the heart ?

Answer 39

CONDUCTION transmit action potentials

Question 40

What is the resting membrane potential of the purkinje fibers ?

Answer 40

VRM = -90mV

Question 41

What is the resting membrane potential of the ventricular fibers ?

Answer 41

VRM = -80mV

Question 42

Ventricular muscle and Purkinje fibers are both permeable to what while resting ?

Answer 42

SODIUM

Question 43

Is the permeability of Sodium in cardiac muscle constant ?

Answer 43

NO cardiac ventricular muscle and purkinjie fibers bother have the ability to depolarize with enough

Question 44

When will you see purkinje fibers or ventricular fibers depolarize on their own ?

Answer 44

When something is WRONG

Question 45

What is the rate of self-depolarization for purkinje or ventricular muscle ?

Answer 45

VERY SLOW

Question 46

What is the threshold potential of the purkinje fibers or ventricular muscle ?

Answer 46

- 70 mV

Question 47

Why does it take a long time for a person to escape a complete heart block naturally ?

Answer 47

LAG time of self-depolarization of the purkinje fibers or ventricular muscles

Question 48

What is the lag time of self depolarization with the first action potential ?

Answer 48

30 + seconds

Question 49

What procedure can lead to complete heart block ?

Answer 49

EYE procedures

Question 50

v + x

Answer 50

Five and dime

Question 51

where is the trigeminal nerve (CN 5) ?

Answer 51

side of the face cranial nerve 5 in charge of sensory perception in the eye socket

Question 52

what is the X in the five and dime ?

Answer 52

cranial nerve 10 stimulating vagal response to decrease heart rate

Question 53

Phase 4 Ventricular electrical is what ?

Answer 53

RESTING membrane potential

Question 54

Phase 0 includes what ?

Answer 54

rapid upstroke due to FAST sodium current to influxx

Question 55

Phase 1

Answer 55

FAST Ca+ current from T-Type Ca+ Channels

Question 56

When do K+ channels start to close ?

Answer 56

End of phase 0 through phase 1 and 2 During action potential

Question 57

When do K+ begin to open

Answer 57

end of phase 2 - beginning of phase 3

Question 58

When do Slow type Ca+ channels open ?

Answer 58

PLATEAU Phase 2

Question 59

Phase 3

Answer 59

K+ channels open to repolarize and reset the cell

Question 60

How long is the action potential in the cardiac muscle ?

Answer 60

200 milliseconds

Question 61

the duration of phase 2 suggest what ?

Answer 61

the duration of the muscle contraction

Question 62

What is the only outward current in cardiac action potentials ?

Answer 62

K+

Question 63

Depolarization of cardiac muscles are initiated by what?

Answer 63

Na+ influx

Question 64

what sustains the depolarization in the cardiac action potential cycle ?

Answer 64

Ca+ influx

Question 65

Does the influx of Ca make the heart muscle positive ?

Answer 65

not enough calcium coming in to make cell that positive - just sustains the contraction period

Question 66

V = iR

Answer 66

Ohm's Law

Question 67

Voltage = Current x R

Answer 67

Ohm's Law Current = i Resistance = R

Question 68

Conduction tissue is found where in the heart ?

Answer 68

Purkinje fibers

Question 69

Positive Deflections on EKG readings occur from what ?

Answer 69

Electrons moving toward positive electrode

Question 70

Negative Deflections on EKG reading occur from what ?

Answer 70

Electrons moving away from positive electrode

Question 71

Depolarization happens in which direction in the heart?

Answer 71

INside to the OUTside endocardium to the epicardium

Question 72

Re-polarization happens in which direction in the heart?

Answer 72

OUTside to the INside Epicardium to the endocardium

Question 73

Area of re-polarization receive current from where ?

Answer 73

depolarized areas transmit current to other areas

Question 74

What happens if the tissue does not have enough energy

Answer 74

It cannot re-polarize - ischemia does not allow normal resetting

Question 75

ischemia leaves tissue in what state?

Answer 75

depolarized constantly tissue - will not reset itself electrically and now conducts currents of injury

Question 76

Currents of injury can give off what ?

Answer 76

currents of injury when there isnt supposed to be any

Question 77

How does the use of leads help us find areas of injury ?

Answer 77

They offer different perspectives of where the injury current can be coming from