42: CARDIOVASCULAR SYSTEM Flashcards
thin filament, a component of a sarcomere, or muscle unit
ACTIN
a hormone released from the adrenal cortex that acts in the
distal convoluted tubule of the kidney to increase retention of sodium
and water
ALDOSTERONE
a peptide hormone that causes vasoconstriction and stimulates aldosterone and ADH release; part of the renin–angiotensin
system
ANGIOTENSIN
released from the posterior pituitary and
acts in the distal convoluted tubule of the kidney to increase water
retention
ANIDIURETIC HORMONE (ADH)
a disruption in cardiac rate or rhythm, also called dysrhythmia
ARRYTHMIA
vessels that take blood away from the heart; muscular, resistance
vessels
ARTERIES
top chamber of the heart, receives blood from veins
ATRIUM
appendage on the atria of the heart, holds blood to be pumped out
with atrial contraction
AURICLE
property of heart cells to generate an action potential without an external stimulus
AUTOMATICITY
the venous system; distensible, flexible veins that are capable of holding large amounts of blood
CAPACITANCE SYSTEM
small vessel made up of loosely connected endothelial cells that
connect arteries to veins
CAPILLARY
a period of cardiac muscle relaxation (diastole) followed
by a period of contraction (systole) in the heart
CARDIAC CYCLE
property of heart cells to rapidly conduct an action potential of electrical impulse
CONDUCTIVITY
resting phase of the heart; blood is returned to the heart during
this phase
DIASTOLE
a disruption in cardiac rate or rhythm, also called an arrhythmia
DYSRHYTHMIA
a shift in the pacemaker of the heart from the sinoatrial node to some other site
ECTOPIC FOCUS
an electrical tracing reflecting the conduction of an electrical impulse through the heart muscle; does not reflect
mechanical activity
ELECTROCARDIOGRAM
the muscle of the heart
MYOCARDIUM
thick filament with projections, a component of a sarcomere, or muscle unit
MYOSIN
a peptide produced by the brain, heart, and
vasculature, which causes natriuresis, excretion of sodium in the urine; degraded by the enzyme neprilysin
NATRIURETIC PEPTIDE
the pulling pressure of the plasma proteins, responsible for returning fluid to the vascular system at the capillary level
ONCOTIC PRESSURE
the systolic blood pressure minus the diastolic blood pressure; reflects the filling pressure of the coronary arteries
PULSE PRESSURE
the arteries; the muscles of the arteries provide resistance to the flow of blood, leading to control of blood pressure
RESISTANCE SYSTEM
functional unit of a muscle cell, composed of actin and myosin molecules arranged in layers to give the unit a striped or striated appearance
SARCOMERE
the normal pacemaker of the heart; composed of primitive cells that constantly generate an action potential
SINOATRIAL (SA) NODE
addresses the contractile properties of the heart: the more the muscle is stretched, the stronger it will react until it is stretched to a point at which it will not react at all
STARLING’S LAW OF THE HEART
contracting phase of the heart, during which blood is pumped out
of the heart
SYSTOLE
chemical in heart muscle that prevents the reaction between actin and myosin, leading to muscle relaxation; it is inactivated by calcium during muscle stimulation to allow actin and myosin to react, causing muscle contraction
TROPONIN
vessels that return blood to the heart; distensible tubes
VEINS
bottom chamber of the heart, which contracts to pump blood out of the heart
VENTRICULAR
a partition that seperates the right half of the heart from the left half
SEPTUM
The RIGHT HALF receives DEOXYGENATED BLOOD from everywhere in the
body through the VEINS (vessels that carry blood toward the heart) and directs that blood into the lungs through the pulmonary artery.
The LEFT HALF receives
the OXYGENATED BLOOD from the LUNGS and directs it into the aorta. The aorta
delivers blood into the systemic circulation by way of arteries (vessels that carry blood away from the heart)
