action potential - transient all-or-nothing reversal of a membrane potential
bradycardia - a reduction in heart rate from the normal level
baroreceptor - a sensory nerve ending that is stimulated by changes in pressure, as those in the walls of blood vessels.
chemoreceptor - a sensory receptor specifically sensitive to certain molecules
conduit - a pipe or channel for conveying fluids
depolarization - The reduction or reversal of the potential difference that exists across the cell membrane at rest
dorsal - towards the back
endothelium - single cell layer forming the internal lining of blood vessels
hemocoel - the space between the endoderm and the ectoderm in some invertebrates
inferior vena cava - vein that brings blood from the lower portions of the body to the right atrium
interstitial fluid - fluid existing between tissues or cells
isometric - an absence of volume change of blood in the contraction of the ventricle in the heart
pacemaker - an excitable cell or tissue that fires spontaneously and rhythmically
posterior - the back of the body
proximal - nearer to the attachment of an extremity or nearer to the point of origin
pulmonary - pertaining to or affecting the lungs
refractory stage - the period during the repolarization of the cell membrane during which the cell cannot generate another action potential.
repolarize - the return of resting polarity of a cell membrane that has been depolarized
sinuses - spaces surrounding an organ
superior vena cava - vein that brings blood from the upper portions of the body to the right atrium
systemic - pertaining to or affecting the body
threshold - the membrane potential at which votage sensitive sodium gates open, permitting a rapid influx of sodium ions, which results in the depolarization phase of an action potential.
ultrafiltration - the process of filtration of colloidal particles by using pressure or suction and a semipermeable membrane
vasoconstriction - contraction of circular muscle of arterioles, decreasing their volume and increasing the vascular resistance
vasodilation - a widening of the lumen or interior space of the blood vessels, increasing the blood flow.
ventral - towards the belly