Electrical Conduction in Heart

1) SA Node, 2) AV Node, 3) Bundle of HIS, 4) Purkinje fibers

Tachycardias = fast / Bradycardia = slow

Sites:
Heart Site: http://www.heartsite.com/html/electrical_activity.html
Wiki: http://en.wikipedia.org/wiki/Electrical_conduction_system_of_the_heart

Depolarization and the ECG

SA node: P wave (Atrial Systole, atrial repolarization)

AV node/Bundles: PR interval (Period of conduction)

Purkinje fibers/ventricular myocardium: QRS complex (Ventricular Systole, rapid ventricular depolarization)

Ventricular repolarization: T wave (Ventricular Diastole, ventricular repolarization)

ST Segment: The ventricles are repolarized

"also referred to as the isoelectric period, represents the period in which the entirety of both ventricles is depolarized. This roughly corresponds to the plateau phase of a ventricular action potential."

QT Segment: The time it takes for the DEpolarization AND REpolarization of the ventricles to occur

Videos:

EKG: http://www.youtube.com/watch?feature=player_detailpage&v=v3b-YhZmQu8

Prokaryotes vs. Eukaryotes

3 Domain System (Classification)

Trends that Affect Boiling Point (ORGANIC)

http://masterorganicchemistry.com/2010/10/25/3-trends-that-affect-boiling-points/

Molecular Forces of Attraction:

http://library.thinkquest.org/C006669/data/Chem/bonding/inter.html

Open/Closed Pipes

1) http://www.youtube.com/watch?v=7M2zB7xeAzc

Sound Waves

- sound waves CANNOT travel through a vacuum (limited to vibrations in a medium)
- Rarefaction: a decrease in the density of something; "a sound wave causes periodic rarefactions in its medium" (6 BR2)

- "compressions & rarefactions"
- Adiabatic: any process that occurs WITHOUT heat transfer (ex: engine breaking) ( ΔT ≠ 0 but Q = 0)
- Isothermal Process: any process that occurs WITHOUT a change in temperature (ΔT = 0 but Q ≠ 0)

- the speed of sound in air at room temp. is about 340m/s!

- v_{sound in solid} > v_{sound in liquid} > v_{sound in gas}

- because solids have stronger forces between them (IMFs), thus greatest restoring force, thus can participate in another compression wave faster, thus can propogate SOUND faster in the medium (6 BR2)

β = 10 log₁₀ (I/I₀)

- Intensity (W/m²) – very LARGE number based on factors of 10, needs to be paired with a LOG expression

- Decible (β) – smaller, more reasonable number, because the answer to a log-based expression!

*** for every drop in intensity by a factor of 10, the decibel level decreases by 10:

- ex: if the intensity of a source increases by 1000 (3 factors of 10), then the decibel level of that sound will increase by 30 (3 x 10)

- ex2: if the intensity (I) increases by a factor of 10, then the intensity level (dB) increases by +10 dB. If the intensity increases by a factor of 100, then the intensity level increases by +20 dB. (USE THIS FOR ANSWER APPROXIMATION!!! Will probably be too complicated/time-wasting to sit and calculate actual logarithms!)

Intensity & Distance: the intensity of sound dissipates with distance by a SQUARED factor

ex: (Kaplan 371) Increasing distance by a factor of 10 decreases intensity by a factor of 100, therefore reducing the sound level by -20 dB.

Flight Time & Range