Unit 2: Intro and Electric Cardio

Question 1

Blood flows throughout the body through ______

Answer 1

pressure gradients
high –> low pressure

Question 2

Flow (Q) =

Answer 2

Q = ∆P / R

Question 3

Poiseuille’s Law:

Answer 3

R = 8nl / πr^4

R ∝ 1/r^4

*Radius of blood vessel raised to the fourth power

Question 4

Length and viscosity are typically _____

Answer 4

constant

Question 5

velocity (v) =

Answer 5

v = Q / A

Question 6

In the capillaries, cross-sectional area ______, therefore velocity of flow ____

Answer 6

increases, decreases

Question 7

Velocity is _____ proportional to total cross-sectional area

Answer 7

inversely

Question 8

If vessel A has a smaller cross-sectional area than vessel B, which has a greater velocity of flow?

Answer 8

vessel A
decreased A, increases v

Question 9

Radius plays the greatest role in determining resistance because…

Radius can be ______
_____ and ______ are constants
Radius factors in the equation to the ____ power

Answer 9

regulated (can dilate and restrict)
Length, viscosity
4th

Question 10

Series resistance:

Artery -> Arteriole -> Capillary -> Venule -> Vein

Total flow (Q) is _____
Pressure gradually _____

Answer 10

CONSTANT

decreases

Question 11

Parallel resistances:

Q aorta ____ Q vena cava
Pressure difference is the _____ across all parallel

Answer 11

Q aorta = Q vena cava
same

Question 12

Are left and right sides of heart in series or in parallel?

Answer 12

IN SERIES

Total flow rate should remain constant aka all the blood that enters the right should leave on the left

Question 13

Flow remains ______ from aorta to capillaries

Answer 13

CONSTANT

Question 14

Velocity of flow is lowest in the ______

Answer 14

capillaries

Question 15

Arteriole A is 2x longer than arteriole B, but the radius arteriole B is 1/2 that of arteriole A. Which arteriole offers less resistance to flow?

Answer 15

Arteriole A

Question 16

Decreasing radius, ______ resistance

Answer 16

increases

Question 17

An artery branches into two arterioles. Suppose one dilates and the other constricts. What happens to flow in each arteriole?

Answer 17

Increases in dilates (radius gets bigger)
Decreases in constricts (radius gets smaller)

Question 18

Pulse pressure (PP) =

Answer 18

PP = SBP - DBP

Question 19

Autorhythmic cells produce electrical signals ______

Answer 19

on their own, don’t need an outside stimulus

Question 20

Firing rate is determined by the fastest autorhythmic cell, which is usually the ______

Order (gets slower):
1.
2.
3.
4.

Answer 20

SA node

1. SA node
2. AV node
3. Bundle of His
4. Purkinje fibers

Question 21

Pacemaker cells are _____ in orgin

Answer 21

muscle

Question 22

In a neuron action potential, you need an outside stimulus that innervates the soma, producing a graded potential that is suprathreshold that reaches the axon hillock.

For pacemaker cells, however, there is no _______ needed because of ______ channels.

Answer 22

outside stimulus
If channels (funny channels)

Question 23

If channels are activated at -60mV ______-polarized

Answer 23

hyperpolarized, not depolarized

Question 24

When If channels open, increase permeability of BOTH ________. However ______ is greater than ______

Answer 24

Na+ and K+
Na+ going into the cell
K+ going out of the cell

Question 25

______ is responsible for the upstroke in pacemaker cells, whereas _____ is responsible in neurons

Answer 25

calcium (Ca2+), sodium

Question 26

______ are the origin of the heartbeat

Answer 26

Pacemakers

Question 27

If you had a pacemaker other than the SA node setting the pace, that would be called an ______

Answer 27

ectopic pacemaker

Question 28

Just like in neurons, voltage gated _____ channels are needed for the upstroke in contractile cells

Answer 28

sodium

Question 29

Difference between pacemaker and contractile? Upstroke?

Answer 29

Upstroke for pacemaker calcium Upstroke for contractile sodium

Question 30

Calcium plateau represents calcium channels being open and competing with ______, giving enough time for calcium to go into cells to have a ______

Answer 30

potassium contraction

Question 31

How do contractile cells depolarize to the threshold?

Answer 31

Pacemaker cells!

Question 32

Contractile cells are syncytium, acts like one cell because of ______

Answer 32

gap junctions

Question 33

________ controls force of contraction, whereas ______ controls rate of contraction

Answer 33

contractile cells pacemaker cells

Question 34

Parasympathetic on pacemaker: ______ cAMP ______ K+ permeability ______ Ca2+ permeability _____ rate of depolarization, ______ heart rate

Answer 34

decrease increase decrease decrease decrease

Question 35

Sympathetic on pacemaker: ____ cAMP _____ Na+ and Ca2+ permeability _____ rate of depolarization, ______ heart rate

Answer 35

increases increases (makes us reach threshold faster) increases, increases

Question 36

The internodal pathways take the signal to the ______ and ______

Answer 36

atrial muscle AV node

Question 37

Current flowing in heart produces a net vector =

Answer 37

average value of 60º from horizontal

Question 38

Action potential is a _____ recording ______ reading ECG is a ____ of action potentials and electrical activity _____ reading

Answer 38

single cell intracellular SUM extracellular

Question 39

_____ angle to lead = flat line

Answer 39

90º doesn't mean there's no activity

Question 40

Overall strongest upward deflections produced by:

Answer 40

Lead II (PARALLEL) to electrical axis of the heart (60º) Upward Deflection (-) -> (+)

Question 41

Segments are regions between two waves, indicated by _____ ex.

Answer 41

flat line P-R segment S-T segment

Question 42

Interval includes at least one _____ and one ____ PR Interval: beginning of ____ to beginning of _____ QT interval: beginning of _____ to the end of ____

Answer 42

segment, wave P wave, QRS complex QRS complex, T wave

Question 43

P wave is _____ depolarization the depolarization of ____ contractile cells

Answer 43

atrial

Question 44

Cannot see depolarization of _____ cells on ECG (ex. SA node, AV node) because they are small but they do happen

Answer 44

pacemaker

Question 45

PQ or PR segment: conduction through _____ and ______

Answer 45

AV node, AV bundle

Question 46

Q and R wave: septal wall ______

Answer 46

depolarization

Question 47

S wave: ventricle ______ Left ventricle is ______ than right ventricle

Answer 47

depolarization thicker

Question 48

ST segment: electrically _____ allows for time for _____

Answer 48

neutral contraction

Question 49

T wave: ventricle ______

Answer 49

repolarization

Question 50

Lead I are two ______ to measure potential difference that connects RA to LA

Answer 50

two electrodes

Question 51

Electrical events ______ mechanical or electrical events ____ mechanical events

Answer 51

PRECEDES initiate

Question 52

The signal during the PR segment is in the _____

Answer 52

AV node

Question 53

Where does the ventricular Ca2+ plateau coincide with the ECG?

Answer 53

ST segment

Question 54

_____ determines the amplitude of the waves

Answer 54

Mass of the tissue

Question 55

< 60 bpm =

Answer 55

bradycardia

Question 56

> 100 bpm =

Answer 56

tachycardia

Question 57

Heart rate = number of _____ / sec = x beats/60 sec

Answer 57

number of R-R intervals/ # of secs = x beats/60 sec

Question 58

First degree heart block: Conduction ______ through ______ Distinguishing factor?

Answer 58

slowed , AV node Prolonged PR segment

Question 59

Third degree (complete) AV block: ____ conduction through AV node P waves _______ from QRS complex SA node are the pacemaker for atriums, Purkinje are the pacemaker for ventricles (you see two different rhythms going on)

Answer 59

NO completely dissociated (a QRS does not always follow a P wave)

Question 60

Distinguishing factor of atrial fibrillation?

Answer 60

No visible P waves, QRS NOT rhythmic

Question 61

Distinguishing factor of ventricular fibrillation?

Answer 61

chaotic