Final Study Cards Flashcards
Provide one example of an every-day device that enables the conversion between analog and digital signals.
A USB microphone, or cell phone
Would an analog to digital converter that is set to sample the output of a pulse plethysmograph once per second be adequate
No, this is measuring 1 Hz where human pulse rates can be anywhere between 40-120 BPM. This sampling rate would be inappropriate for HR data
Calculations for Amplitude, Period Time and Frequency
Amplitude: Change in resting to peak of contraction (V2-V1).
Period time: Time for one contraction to occur (T2-T1)
Frequency: Number of contractions in a minute
An analog electrical signal can be converted into a digital signal for computer analysis by
An analog to digital (A/D) converter
What is biological noise?
Data collected by the sensor that is converted and transduced to be quantified as signal from the phenomena of interest.
A physiological signal such as blood pressure is converted into an electrical signal, i.e. a voltage, by:
An analog-to-digital (A/D converter)
Distinguish between urine osmolality and urine specific gravity
While osmolality is a measure of dissociated ions in a solution, it will also pick up some larger components if they contribute to osmotic pressure.
Specific gravity reports, and is more heavily influenced by larger molecules, but is also influenced by dissociated ions to a lesser degree.
What is the effect of ADH? How will drinkning Cola affect ADH levels?
ADH increases water reabsorption at the level of the kidney (collecting duct of the nephron) Which increases water retention, blood volume and bloop pressure.
Cola will increase BP due to front load increase of water. The slight salt does not offset this effect with blood osmolarity and will actually decrease ADH, the result is lower water re-absorption
Caffiene is a competitive antagonist for adenosine receptors, which effects GFR by opposing vasoconstriction in the afferent arteriole in the nephron mediated by type 1 AR and tubuloglomerular feedback.
What is the physiological mechanism underlying the diuretic effects of alcohol?
Alcohol is able to sequester ADH on the blood and therefore increase UFR as less water re-absorption is occuring. Individuals drinknig beer as compared to individuals drinking water will experience increase UFR and decreased osmolarity.
What types of adrenergic receptors are found on goldfish melanophores
All types (a1, a2, b1, b2). The most potent effect are seen by a2 bdining of agonist/ antagonist. The effects on intracellular cAMP from antagonists binding led to inhibition of aggregation.
Phenylephrine
a1 agonist, Fish Lab
Isoproterenol
Non-Selective B agonist (Fish/Rat lab)
Phentolamine
a1/a2 Antagonists
Propranolol
B1/B2 Antagonist
What is the predominant secondary messenger in adrenergric adctivation/ inqactivation in fish melanophores
cAMP
Distinguish between passive and active tension
Passive: Muscle tension an a unit of muscle when there is no input to flex (isometric)
Active: Muscle tension when muscle is activated or flexing (isometric)
How does electrical stimulus trigger muscle contraction?
Electrodes are able to stimulate muscle contraction by opening voltage gated Ca2+ channels. Accumulation of Ca2+ in sarcoplasm which bind TnC, muscle contraction
Would you see a graded response if you stimulated only the sciatic nerve
Yes, We instead will measure the compound action potential (CAP) or proportion of axons that reach threshold potential
Relationship between maximum amplitude of contraction and stimulus frequency
The relationship is defined by cytosolic Ca2+ concentration and cells ability to clear Ca2+. This leads to incomplete and eventually complete tetanus
A muscle twitch is defined as all or none, then why was there an increasing amplitude in muscle tension and eventually a plateau?
We observed the gradual increase in tension/ contraction with increasing stimulus amplitude because we are seeing many muscle fibres with many different tresholds being activated.
At low stimulus amplitudes, only low threshold fibers are being activated
Muscle Latency
The time between when stimulus is applied to when actual contraction is seen
Contraction time
In the presence of ATP and calcium, Mysoin heads crawl along acting to shorten the sarcomere.
The time that the muscle is shortened
Muscle Relaxation
Contraction goes back down as Ca2+ leaves the sarcolema, membranes repolarize and we see muscle tension decrease
Absolute refractory period
When the Action potential is occuring, absolutely no other depolarizations may occur
Relative refractory period
Follows immediately after absolute refractory period. A second action potential may be produced but will require a stronger stimulus
Compound action potential (CAP)
the culmination of many action potentials as recroded by the NBC-300 Nerve chamber. fascicles of neurons are arranged into nerves including alpha, beta, gamma and sigma.
How does BP change with exercise
Blood oxygen decrease and increased circulating carbonic acid increase HR, this along with increased blood volume increase BP which is offset by vasodilation by binding if catecholamines to B2 receptors
ECG
Electrocardoigram Invented by Willem Eintoven. Record QRS complexes as a measure of heart rate
Valsalva maneuver
Used to increase pleural pressure on the heart, the result being an initial increase in heart rate
Frank-Starling relationship
The relationship between ventricular stretch and blood volume entering the heart
Q10 effect
Q10=(R2/R1)^10C/(T2-T1)
Stretch relaxation smooth muscle
Enhanced capacity of smooth muscle to change its length. Gap junctions and varicosities in neurons allow for this differnece
Smooth muscle length tension relationship
Not distinct
