Chapter 6 Flashcards
Arteries
Blood vessels that transport away from the heart
Arterioles
The smallest arteries that transport blood from larger arteries to the capillarie
Atherosclerosis
A condition that involves loss of elasticity, thickening, and hardening of the arteries
Atrioventricular (AV) node
The specialized mass of conducting cells in the heart located at the atrioventricular junction
Baroreceptor
Stretch receptor located within the cardiovascular system that senses changes in blood pressure
Bradycardia
A resting heart rate lower than 60 beats per minute
Capillaries
The smallest vessels transporting blood from the heart to the tissues and the actual sites of exchange
Cardiac Cycle
The period that includes all events between two consecutive heartbeats
Cardiac Output
The volume of blood pumped out by the heart per minute; Heart Rate x Stroke Volume
Chemoreceptor
A sensory organ capable or reacting to a chemical stimulus
Diastolic Blood Pressure (DBP)
The lowest arterial pressure, resulting from ventricular diastole (the resting phase)
Ejection Fraction (EF)
The fraction of blood pumped out of the left ventricle with each contraction, determined by dividing stroke volume by end-diastolic volume and expressed as a percentage
Electrocardiogram (ECG)
A recording of the heart’s electrical activity
Electrocardiograph
A machine used to obtain an electrocardiogram
End-Diastolic Volume (EDV)
The volume of blood inside the left ventricle at the end of diastole, just before contraction
End-Systolic Volume (ESV)
The volume of blood remaining in the left ventricle at the end of the systole, just after contraction
Extrinsic Neural Control
Redistribution of blood at the system or body level through neural mechanisms
Heart Murmur
A condition in which abnormal heart valve sounds are detected with the aid of a stethoscope
Hematocrit
The percentage of cells or formed elements in the total blood volume. More than 99% of the cells or formed elements are red blood cells
Hematopoiesis
Increased red blood cell concentration by increased production of cells
Hemoglobin
The iron-containing pigment in red blood cells that binds oxygen
Intercalated Disks
Specialized cell junction in the myocardium where one muscle cell connects to the next
Mean Arterial Pressure (MAP)
The average pressure exerted by the blood as it travels through the arteries. It is estimated as: MAP = DBP + [0.333 x (SBP - DBP)]
Mechanoreceptors
An end organ that responds to changes in mechanical stress, such as stress, compression, or distension
Muscle Pump
The rhythmic mechanical compression of the veins that occurs during skeletal muscle contraction in many types of movement and exercise - such as walking and running - and assists the return of blood to the heart
Myocardium
The muscle of the heart
Pericardium
A double-layered outer covering of the heart
Premature Ventricular Contraction (PVC)
A common cardiac arrhythmia that results in the feeling of skipped or extra beats caused by impulses originating outside the SA node
Purkinje Fibers
The terminal branches of the AV bundle that transmit impulses through the ventricles six times faster than through the rest of the cardiac conduction system
Sinoatrial (AV) Node
A group of specialized myocardial cells, located in the wall of the right atrium, that control the heart’s rate of contraction; the pacemaker of the heart
Stroke Volume (SV)
The amount of blood ejected from the left ventricle during contraction; the difference between the end-diastolic volume and end-systolic volume
Systolic Blood Pressure (SBP)
The greatest arterial blood pressure, resulting from systole (the contracting phase of the heart)
Tachycardia
A resting heart rate greater than 100 beats per minute
Vasoconstriction
The constriction of narrowing of blood vessels
Vasodilation
The dilation or widening of blood vessels
Veins
Blood vessels that transport blood back to the heart
Ventricular Fibrillation
A serious cardiac arrhythmia in which the contraction of the ventricular tissue is uncoordinated, affecting the heart’s ability to pump blood
Ventricular Tachycardia
A serious cardiac arrhythmia consisting of three of more consecutive premature ventricular contrations
