Cardio physiology Guyton/Nagelhout

Increased SNS activity increases ______, _______, and ______.

Sympathetic nervous system activation results in mobilization of myocardial -__ _____ and _________ for energy use by the myocardial cells.

Preganglionic SNS fibers originate from the cells in the __________ columns of the _______ _______ segments of the _______ _____.

SNS fibers synapse at the ____ through the _______ _______ paravertebral ganglia.

SNS spinal cord segments are known as __________ ________.

Preganglionic PNS fibers originate in the dorsal motor nucleus of the medulla

Suppression or blockade of thoracic (1st-5th) portion of the spinal cord by regional anesthesia causes hypotension and bradycardia by inhibition of parasympathetic ganglia.

Parasympathetic tone decrease _____ _____.

Maximum vagal nerve stimulation reduces contractile by ____ %

Maximum stimulation of SNS increases contractility by ____ %

Physiologic effects of PNS stimulation occur because of increased permeability of cardiac muscle cell membranes to which ion? (Resulting in hyperpolarization)

Hyperpolarization of the cardiac muscle cell membrane makes SA and AV node more excitable.

_______ is the neurotransmitter of the PNS.

Located along the epicardial surface at the junction of the SVC and RA.

SA node speed of conduction ___ m/sec

Intrinsic rate of SA node ____ to ____ bpm

_______ ________ preferential conduction pathways between the SA and the AV node.

AV node impulse conduction is considerably slower than any other region within the normal cardiac conduction at ____ m/sec.

___ _______ is the preferential channel for conduction of the action potential from atria to the ventricles.

Conduction velocity of from the bundle of His into the left and right bundle branches along the intraventricular septum ____ m/sec.

Purkinje fibers fire at a rate of ___ to ___bpm

SNS stimulation catecholamines are released from the CNS and the _______ ________.

When catecholamones interact with Beta-1 receptors, this increases myocardial cell permeability to _______ and ________.

The force of myocardial contraction is dependent on the quantity of _____ present within the cardiac cell.

Inhibition of calcium influx into cardiac muscle cells is the proposed mechanism by which _____ anesthetic agents cause depression of myocardial contractility.

The resting cell membrane is relatively permeable to _______ and relatively impermeable to both _______ and _______.

During Phase 0, fast sodium channels open between -____ to -____ (threshold potential).

______ anesthetics such as ______ have an inhibitory effect on Phase 0 by decreasing the influx of sodium.

Phase 1 (early rapid repolarization) reaches +____mV to +____mV

Slow calcium channels open at -____mV to -_____mV.

Inward influx of calcium flux delays and prolongs the ______ refractory period.

Phase 2 (Plateau phase) maintains a membrane potential near ____ mV.

Calcium channel blockers exert their pharmacological effect during phase __.

Phase 3 slow _____ channels become inactivated and is sustained by accelerated ______ efflux.

Phase 4 (resting potential/diastolic repolarization phase) resting membrane potential is restored ______ ICF to ECF and ____ and ____ ECF to ICF

______ lenthens the duration of the Phase 4 by decreasing the cardiac cell membrane’s permeability to _____ ion; delaying the onset of the resting membrane potential.

Period lasts from Phase 0 to the middle of Phase 3.

The relative refractory period is the time during which

Period lasts from the middle of Phase 3 to the beginning of Phase 4. (Occurs during the T wave)

Resting membrane potential of the SA node.

Phases of diatole (name the 3)

Atrial systole is the final period of rapid filling and is commonly referred to as atrial kick.

In patients with mitral stenosis, atrial kick may be responsible for up to ___% of the ventricular filling.

_______ contraction begins with the closure of the mitral valve and lasts until the opening of the aortic valve.

The a wave represents the end of ____ systole just before mitral valve closure.

The ____ wave represents ______ contraction and is produced by bulging of the mitral valve caused by increasing left ventricular pressure.

The ___ wave represents increased pressure in the LA caused by blood return from the pulmonary veins before mitral valve opening.

During systole, blood flow ceases to the __________ from compression due to myocardial muscle fiber tendon.

Flow through the _______ vessels is NOT affected during systole.

Myocardial oxygen demand is determined by: (4)

Myocardial oxygen supply is determined by: (5)

Increased _____ _____ is the most important factor that negatively affects myocardial oxygen consumption.

80-90% of coronary filling and myocardial perfusion occurs during

Beta blockers increase _____ and decrease _____, protecting the heart from ischemia.

Myocardium extracts 65%-70% of the available oxygen from hemoglobin.

Coronary artery vasodilation can increase coronary blood flow by ____ to _____ times.

List the vasodilators substances released by the endocardium in response to decreased oxygen delivery or concentration. (7)

Coronary blood flow is maintained at a constant flow rate through a MAP range of ____ to _____ mmHg.

Major determinant of coronary perfusion pressure is _____ blood pressure.

Normal EF:

Match each definition with the term.

Chemoreceptor response is elicited from ______, ______, and _______.

Chemoreceptor reflex stimulates the SNS to

Threshold potential of the SA node

Cardioaccelerator fibers originate in the higher thoracic segment of

Local anesthetics

Opioids

Volatile anesthetics