A & P 314 Lab Exam 1 Quiz 3

Blood pressure

force of blood against the walls of the arteries as it circulates through the body, in millimeters of mercury (mmHg)

systolic pressure

pressure in the arteries when the left ventricle of the heart contracts and pushes blood into the aorta and the systemic circulatory system, higher number

Diastolic pressure

pressure in the arteries when the left ventricle is at rest, lowest number

Hypotension

blood pressure below 90 mmHg over 60 mmHg, symptoms include blurry vision, confusion, dizziness, and weakness

hypertension

blood pressure above 130 mmHg over 80 mmHg, contributes to burst blood vessels, blood clotting, stroke, or heart attack

Pulse pressure

difference between the systolic and diastolic pressures

mean arterial pressure

Sphygmomanometer

medical device used to measure blood pressure. It consists of an inflatable cuff that is wrapped around the upper arm and connected to a gauge that displays the pressure.

Korotkoff sounds

series of sounds heard through a stethoscope when measuring blood pressure with a sphygmomanometer. These sounds are produced by the turbulent flow of blood through the arteries as the pressure in the cuff is gradually released

cardiac conduction system

responsible for generating and coordinating the action potentials that control the heartbeat

sinoatrial node

small cluster of specialized cardiomyocytes, in the superior margin of the right atrium, natural pacemaker of the heart, generates electrical impulses that initiate each heartbeat

atrioventricular node

cluster of specialized cardiomyocytes located in the inferior margin of the right atrium, near the opening of the coronary sinus. Serves as a gatekeeper and delays the action potential from the SA node, allowing time for the atria to contract and fill the ventricles with blood before the ventricles contract

bundle of His

bundle of specialized cardiomyocytes that carries the action potential inferiorly through the interventricular septum to the apex of the heart and splits into the Purkinje fibers

Purkinje fibers

specialized muscle fibers that branch out from the bundle of His and spread throughout the ventricles, deliver the action potential to the muscle cells of the ventricles, causing simultaneous ventricle contraction

Pacemaker Potential

slow influx of Na+ ions resulting in a gradual depolarization

electrocardiogram

composite image of the change in cardiac voltage over time

P wave

first small peak, atrial depolarization

QRS complex

sharp downward, upward, downward spike, ventricular depolarization

T wave

final small peak, ventricular repolarization, highlighted region

Tachycardia

a heart rate above 100, often caused by physical exertion, sympathetic stimulation, and fever

regular sinus rhythm

most common ECG tracing in healthy adults, BMP from 60 to 100 BPM. The QRS complex will be narrow, and the P wave and T wave will be upright

Bradycardia

heart rate of <60 BPM. In healthy adults, it typically is not a concern until the heart rate drops below 50 BPM

Atrial fibrillation

an irregular, chaotic rhythm with no discernable P waves, but does have a discernable QRS complex, from the atria firing out of sync quivers and jiggles instead of pumping blood increasing risk of blood clots