Murmers caused by                                      are usually                  

Murmers caused by  septal  defects are usually Congenital                 

In mitral                , mitral valve becomes thickened & calcified, impairing blood flow from left atrium to left ventricl

In mitral stenosis, mitral valve becomes thickened & calcified, impairing blood flow from left atrium to left ventricl

The pause sound between the Lub Dub is called the

Quiescent period

The first sound... the Lub... refers to the

AV valves closes

Ventricular pressure rises above atrial pressure and (beginning of ventricular systole)

The second sound... the Dub... refers to

When the SL (semilunar) valves snap shut at beginning of ventricular relaxation

Ascultation

is when you listen for a sound

Ectopic Pacemakers

Other tissues in the heart that are spontaniously active

Tissues other than the typical electrical pathway that can substitute in the case of nodal failure

Properties of Ectopic Pacemakers

• Slower than SA node
• Stimulated to produce action potentials by SA node before spontaniously depolarize to threshold
• If APs from the SA node do not reach these then they will generate APs by themselves

Third Degree or Complete AV nodal Block

Occurs when AV node is damaged

AV node block

When conduction through the AV node is less than .2 seconds

CAUSES?

First Degree AV node block

CAUSES long P to R interval

When only one out of 2-4 atrial action potentials can pass to ventricals?

CAUSE?

Second degree AV block

P waves with no QRS waves

When no atrial activity passes to the ventricals

CAUSE

Third degree AV block

Ventricals are driven slowly by the bundle of his and the purkinjes  

Nodal Rhythm

when your SA node stops firing

Flutter

Heart Rate is anywhere from 200-300 bpm

Coordinated contraction

Fribrillation

Contraction of myocardial cells is UNCOORDINATED and pumping is ineffective

Defibrillation is needed

Electrical Defirillation

Resynchronizes heart by depolarizing all cells at the same time

Arrhythmias

Abnormal Heart rhythms

Bradycardia

Heart rate is below 60 bpms

Tachycardia

Heart rate is above 100 bpms

What does P wave coorespond to?

Depolarization of the SA node

What does the QRS complex coorespond to?

Ventricular Depolarization

What does the T wave correspond to?

Ventricular Repolarization

How long is the Quiescent period

.4 sec

Atrial Systole

.1 sec

Ventricular Systole

.3 sec

What is the electrical pathway in the heart?

1. SA node
2. Internodal pathway
3. AV Node
4. AV bundle
5. Bundle Branches
6. Purkinje Fibers

Atrial depolarization, initiated
by the SA node causes what wave

P wave

      Ventricular depolarization
begins at apex, causing the ___________.

Atrial repolarization occurs.

QRS complex

Ventricular repolarization
begins at apex, causing the
____wave.

T

How long does it take for electrical conduction to go from the SA to the AV node?

AV to the AV bundle of His?

50 msecs

.05msecs

Why is the AV node slow?

Thinner Myocytes

Fewer Gap Junctions

What is the Resting Membrane Potential for a Myocardial cell?

-90 mV

What is the Resting Membrane Potential for SA Nodal cells

-60 mV

What is the threshold for SA node cells?

-40

What is the peak action potential for a SA node cell?

About 5

What is the peak for a Myocardial cell?

+25

What Ion Influx causes an action potential?

CA+

What Ion Eflux causes repolorization?

K+

What happens at -40?

CA2+ channels open allowing calcium to flowing which causes an action potential

What happens at +5?

Ca2+ channels close and K+ channels begin to open which causes repolarization... the K+ Ions rush into the cell

Autorythmic cells

• Have an unstable resting potentials called pacemaker potentials
• Initiate action potentials
• Use calcium influx rather than sodium for rising phase fo the action potential
• Utilize Voltage regulated Ion Channels

Depolarization

Loss of polarity... cell becomes more positive

Action potential

is a rapid up and down voltage shift

Repolarization

Membrane polarity regained as the cell becomes more -

Resting Membrane potential

Difference in voltage across the membrane

Maintained by the Sodium Potassium Pump

Extracellular Fluid ECF

The fluid outside the cell

Intracellular Fluid ICF

Fluid inside of the cell

Cardiac Muscle Cells

Striated short fat branched and interconnected

Connective tissue matrix (endomysium)

 connects to the fibrous skeleton

T tubules

Wide but less numerous

SR is simpler than in skeletal muscle

Numerous large mitochondria 25-35% of cell volume

Desmosomes

Prevent cells from separating during contraction

Gap Junctions

Allow ions to pass; electrically couple adjacent cells

Heart muscle behaves as a functional ___________

Syncytium

Sarcoplasmic Reticulum is filled with this

Calcuim

Muscles require ______ to contract

Ca+

Oxygen Storage Molecule

Myoglobin

Acts as a energy reserve

Glycogen

Energy source for the heart

60 % from fatty acids

35% form glucose      

5% from ketones, lactic acid, and amino acids

The LARGE number in BP

Systole

The small number in BP

Diastole

The relaxation phase of the heartbeat

Diastole

Cardiac Rythm

70 to 80 beats per minute

One heart beat =.8 seconds

Contraction of the heart is also known as

Systole

What type of cells make up the electrical system of the heart system

Modified Myocytes- Autorhythmic cells

Contractility is

The increase in contractile strength, independent of stretch and EDV

Positive Inotrophic

Positive Factors that incluence cardiac muscle