Physio Lecture 17 (Exam 3)

Front 1

What does ECG stand for?

Back 1

Electrocardiogram

Front 2

What is an ECG/EKG?

Back 2

It is an electrical record of the hearts electrical events.

Front 3

Are the axis of the heart and the major dipole of the heart related?

Back 3

The axis of the heart is a
calculation that is made by comparing the "view" of the dipole from two different leads.
Using the comparison, this allows you to identify the major dipole direction.

Front 4

What is the major electrical connection between the atria and the ventricles?

Back 4

The major electrical connection between the atria and the ventricles is the AV node (atrioventricular
node), without this connection there would be no electrical cross-talk between the atria and the ventricles.

Front 5

What are the major events seen in an ECG, and what does each indicate?

Back 5

The p-wave corresponds to the initiation of the depolarization of the atrial contracting cells. The QRS complex corresponds to the initiation of the depolarization of the ventricular contracting cells and also has the atrial repolarization event buried in the signal. The t-wave corresponds to the initiation of the repolarization of the ventricular contracting cells.

Front 6

What are the normal time intervals of each segment of the ECG?

Back 6

P-R interval = 0.12-0.20sec; QRS complex = under 0.10 sec; Q-T interval under 0.38 sec

Front 7

What does axis of the lead refer to?

Back 7

The arrangement of the negative and positive electrodes of the lead.

Front 8

What 4 pieces of information, that we discussed in class, can you obtain from an ECG?

Back 8

1. Heart rate.
2. Presence of arrhythmias.
3. Presence of myopathes (ischemic areas).
4. Problems with the conducting system.

Front 9

What is bradycardia?

Back 9

Bradycardia is an extremely slow resting heart rate (<60 bpm).

Front 10

What is tachycardia?

Back 10

Tachycardia is an extremely high resting heart rate (>100 bpm).

Front 11

Are bradycardia and tachycardia ever considered normal?

Back 11

Bradycardia normally occurs when we sleep, and also
well trained atheletes have resting heart rates that can be <60 bpm. At rest, tachycardia
is not considered normal, but with exercise, heart rates will easily become >100 bpm.

Front 12

What type of arrhythmia is life-threatening?

Back 12

Ventricular fibrillation

Front 13

Describe what is happening in the condition know as AV node heart block.

Back 13

Heart block is a condition in which the AV node begins to deteriorate (or die). As heart block progresses, the ventricles will slowly start to beat at the rate of the pacemaker potentials
of the Purkinje fibers

Front 14

What characterizes each phase of AV node block?

Back 14

1st degree - longer than normal P-R interval; 2nd degree - not all atrial depolarization events sent to the ventricles, detected on the ECG by having some P-waves that do not have QRS
complexes following them; 3rd degree (complete) - when atria and ventricles are beating
at completely different paces.

Front 15

What are the pacemaker potential rates for the different conducting cells of the heart?

Back 15

The rates of the pacemaker cells are as follows: SA node =
~100 bpm, but because of parasympathetic dominance, it is slowed to~ 75-80 bpm; the
AV node ~ 60 bpm; and the Bundle of His/Purkinje fibers ~20-40 bpm.

Front 16

What events are seen in an ECG that correspond to a PVC?

Back 16

In an ECG, the events that occur with a PVC are 1. No p-wave. 2. Both an enlarged and spread out QRS complex. 3. A
compensatory pause.

Front 17

What are the 2 categories of defense mechanisms in our bodies?

Back 17

The 2 categories of defense are
innate and adaptive immunity.

Front 18

Which cells are primarily involved adaptive and innate immunity? .

Back 18

Innate immunity involves phagocytic cells, such as neutrophils and macrophages; adaptive immunity involves
lymphocytes (B and T-cells)

Front 19

What is innate immunity?

Back 19

Innate immunity is our primary form of attack against a pathogen.

Front 20

Is innate immunity considered a specific or non-specific response?

Back 20

It non-specifically attacks substances that are perceived as "non-self".

Front 21

What is phagocytosis?

Back 21

Phagocytosis is the process in which a cell or a foreign substance in engulfed so that it can be degraded

Front 22

What types of cells perform phagocytosis?

Back 22

The cells which perform
phagocytosis are netrophils and monocytes/macrophages

Front 23

What are the two terms that refer to the movement of WBC from the blood into the tissues? .

Back 23

Movement of WBC's our of the blood stream and into the tissues is called diapedesis or extravasation

Front 24

What is adaptive immunity?

Back 24

Adaptive immunity is immunity that is very specific to a
particular antigen

Front 25

What is a pathogen? Examples?

Back 25

A pathogen is any substance capable of causing
disease. Examples are bacteria, viruses, or parasites

Front 26

Can any foreign molecule act as an antigen?

Back 26

No, most antigens are proteins and must be of a certain size

Front 27

What mechanisms are involved in local inflammation?

Back 27

Both innate and adaptive

Front 28

What type of cells release histamine?

Back 28

Histamine is released by mast cells (which are derived from basophils).

Front 29

During inflammation, what changes occur in the local vessels and what causes it?

Back 29

Primarily due to the release of histamine, heparin, and prostaglandins from Mast cells, the vessels vasodilate, allowing more blood flow to the area, also, the
histamine causes the pores in the endothelial cells to enlarge, making the vessels more
permeable.

Front 30

During inflammation, why does the area swell?

Back 30

An area will swell at a site of inflamation because mast cells secrete heparin, histamine, prostaglandins, leukotrienes, cytokines, & TNF-a. All of these produce redness, swelling, pus, & pain. (The redness is from enhanced blood flow to the area, the swelling is from more fluid and cells entering the interstitial space,
the pus is from an accumulation of WBC’s that are engulfing the pathogen and
sometimes dying from toxins produced by those pathogens, and pain is associated with
more fluid in the interstitial space as well as activation of pain receptors by some of the
chemicals produced by the pathogens).

Front 31

Electrocardiogram

Back 31

An electrical activity record of the heart, using surface electrode, one region can momentarily be depolarized, and another region depolarized, and this depolarization can be recorded from the cells surface, can tell us Heart rate, arrhythmia’s, damage to heart walls (myopathes), damage to the conduction system

Front 32

Dipole

Back 32

Regions in the heart that are going to be depolarized and repolarized (spread of electrical activity), extended throughout the body and can be recorded at the surface using electrodes that contant the skin

Front 33

Sinoatrial Node

Back 33

A small specialized autorhythmic region in the right atrial wall of the heart that has the fastest rate of spontaneous depolarizations and serves as the normal pacemaker of the heart

Front 34

Internodal Pathway

Back 34

The pathway found between the SA node and the AV node that creates a temporary pause

Front 35

Atrioventricular Node

Back 35

A small bundle of specialized cardiac cells at the junction of the atria and ventricles that is the only site of electrical contact between the atria and ventricles

Front 36

Bundle of His

Back 36

A tract of specialized cardiac cells that rapidly transmits an action potential down the interventricular septum of the heart

Front 37

Purkinje Fibers

Back 37

Small terminal fibers that extend from the bundle of his and rapidly transmit an action potential throughout the ventricular myocardium

Front 38

QRS Complex

Back 38

Ventricular depolarization (atria repolarizing simultaneously)

Front 39

T Wave

Back 39

Ventricular repolarization

Front 40

PR Interval

Back 40

AV nodal delay, atrial cells contract, electrical activity and AV nodal delay, includes P wave

Front 41

Arrhythmia

Back 41

Abnormal heart rhythms, can be detected on an ECG

Front 42

Myopathes

Back 42

Damage to the heart walls

Front 43

Bradycardia

Back 43

Slower than normal heart rate <60/min

Front 44

Tachycardia

Back 44

Faster than normal heart rate >100/min

Front 45

Flutter

Back 45

Contraction rate can be between 200-300/min, life threatening, blood is flowing but at a small volume

Front 46

Fibrillation

Back 46

Contraction of myocardial cells is uncoordinated and pumping ineffective, life threatening, heart is shaking, and no blood flow

Front 47

Electrical Defibrillation

Back 47

Resynchronizes heart by depolarizing all cells at same time, given a shock because you want to depolarize all cells at the same time

Front 48

1st Degree (primary) AV Block

Back 48

Arrhythmias, PR > 0.2 sec when conduction through AV node >0.2 sec, causes long PR interval (longer delay of AV)

Front 49

2nd Degree (Secondary) Av Block

Back 49

Arrhythmias, Is when only one out of 2-4 atrial action potentials can pass to ventricles, causes P waves with no QRS

Front 50

3rd Degree (Complete) AV Block

Back 50

Arrhythmias, No atrial activity passes to ventricles, ventricles drive slowly by bundle of His or purkinjes

Front 51

Self vs Nonself

Back 51

Self belongs in the body, nonself does not and is a foreign, central theme of the immune system

Front 52

Innate Immunity

Back 52

Is nonspecific, inherited as part of structure of each organism, first line of defense against invading pathogens, includes not only phagocytic cells, but epithelial barriers,

Front 53

Adaptive Immunity

Back 53

Is specific, a function of lymphocytes and changes with exposure

Front 54

PAMP’s (pathogen associated molecular patterns)

Back 54

Patterns of molecules on outside of cell that help it be easily identifies as foreign, produced only by microorganisms and triggers phagocytosis

Front 55

LPS (Lipopolysaccharides)

Back 55

Gram negative type of pathogen associated molecular patterns (PAMP’s)

Front 56

Peptidoglycan

Back 56

Gram positive type of pathogen associated molecular patterns (PAMP’s)

Front 57

Extravasation

Back 57

A type of diapedesis that WBC’s exit capillaries by when ingesting pathogens

Front 58

Diapedesis

Back 58

A form of extravastion that WBC’s exit capillaries by when ingesting pathogens

Front 59

Pyrogens

Back 59

Released by WBC’s in response to endotoxin from gram negative bacteria that cause a thermostat reset and increases temperature, signaling molecule is given off by cytokines that resets hypothalamus, increase in temperature causes proteins in body to denature and enzymes to not work, also decreases number of bacteria dividing producing less bacteria for immune system to clean up

Front 60

Antigen

Back 60

Found on bacterial cells, a large complex molecule that triggers a specific immune response against itself when it gains entry into the body

Front 61

Antibodies

Back 61

Produced by B cells to fight against bacterial antigens, an immunoglobin produced by a specific activated B lymphocyte (plasma cell) against a particular antigen, binds with a specific antigen against which it is produced and promotes the antigenic invaders destruction by augmenting nonspecific immune responses already initiated against the antigen

Front 62

Opsinization

Back 62

Phagocytic activity of neutrophils, macrophages, and monocytes

Front 63

Mast Cells

Back 63

Cells located within connective tissue that synthesize, store, and release histamine, as during allergic responses

Front 64

Heparine

Back 64

A chemical released from mast cells that produce swelling, redness, warmth, pus and pain, recruit more leukocytes

Front 65

Histamine

Back 65

A chemical released from mast cells or basophils that brings about vasodilation and increased capillary permeability; important in allergic responses, creates swelling, redness, warmth, pus, and pain and recruits more leukocytes

Front 66

Leukotrienes

Back 66

A chemical released by mast cells that produce swelling, redness, warmth, pus and pain, and recruits more leukocytes