lab heart physiology

order of cardiac conduction pathway

SA node, atria, AV node, bundle of his, bundle branches, purkinjee fibers

What causes the first heart sound (LUB)

closure of the AV valve

what causes the second heart sound (DUB)

closure of the aortic and pulmonary valves

what is the neurotransmitter for the parasympatheic system

acetocholine (ACh)

What is the receptor for the parasympatheic system

Muscarinic receptors

what effect does parasympatheic system have on HR

decreases HR (negative chronotropic effect)

What is the agonist drug for the parasympatheic system

Acetylcholine

What is the antagonist drug for the parasympatheic system

atropin

what is the neurotransmitter for the sympatheic system

norepinephrine (NE)

what is the receptor for the sympatheic system

Adrenergic receptors

what effect does the sympatheic system have on HR

increases HR (positive chronotropic effect)

what is the agonist drug for the sympatheic system

Epinephrine, norepinephrine, beta-agonists

what is the antagonist drug for the sympatheic system

Beta-blockers

what happens during the p wave

Atrial depolarization

what happens during the QRS complex

Ventricular depolarization

what happens during the t wave

Ventricular repolarization

what happens during the P-R interval

Time from the onset of atrial depolarization to the onset of ventricular depolarization

what happens during the Q-T interval

Time between the start of ventricular depolarization and the end of ventricular repolarization

what is the normal time for a small box

0.04 seconds

what is the normal time for a large box

0.2 seconds

how many small boxes make up a large box

5 small boxes

what is the formula for BMP

BMP = (# beats per 6 sec) x 10

what is the normal rate for HR

60-100bmp

what is tachycardia

fast heart rate (>100)

what is bradycardia

slow heart rate (<60)

what is the normal range for blood pressure

120/80 mmHg

what are factors that increase blood pressure

increase cardiac ouput, increase blood volume, contrsiction of blood vessles, stress, high sodium intake

what are factors that decrease blood pressure

decrease cardiac output, blood loss, dehydration, vasodilation

what is systolic pressure

pressure in arteries when the heart contracts

what is dyastolic pressure

the pressure in the arteries when the heart is at rest (in between beats)

what happens to the HR as a person rests

normal (60-100)

what happens to the BP as a person rests

normal (120/80)

what happens to the ECG as a person rests

normal P-R and QT interval

what happens to the HR as a person excersies

increases

what happens to the BP as a person excersies

increase

what happens to the ECG as a person excersies

shorter P-R intervals

what happens to HR as a person changes body position

slight increase

what happens to BP as a person changes body position

decrease initally

what happens to ECG as a person changes body position

unchanged