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Understanding EKGs-2
Based on the book by Beasley, 2nd Edition
Question | Answer |
---|---|
Freshly oxygenated blood traveling through the aortic valve also enters the ________ ______ during diastole when the aortic valve closes to accomplish myocardial oxygenation. | Coronary arteries |
What is the VITAL function that occurs in the 2nd or middle component of pulmonary circulation? | gas exchange |
What is characterized by gas exchange? | Carbon dioxide is exchanged for oxygen in the pulmonary alveolar-capillary network. |
What is the cardiac cycle? | The cardiac cycle is the actual time sequence between ventricular contraction and ventricular relaxation. |
What is systole or ventricular systole? | Systole or ventricular systole is simultaneous contraction of the ventricle. |
What is diastole? | Diastole is synonymous with ventricular relaxation. |
Why does the heart function as a unit? | The heart functions as a unit because both atria contract simultaneously, then both ventricles contract. |
What happens when the atria contract? | The ventricles are filled with blood to their limit. |
What happens when simultaneous contraction of the ventricles occur? | Blood is ejected into the pulmonary and systemic circulations systems. |
During ventricular contraction, what is occuring to the mital (bicuspid) and tricuspid valves and the the pulmonic and aortic valves? | The mital (bicuspid) and tricuspid valves are closed by the pressure of the contraction, while the pulmonic and aortic values open. |
How much blood fills the ventricles during ventricular diastole? | 70% of the blood that has collected in the atria fills the ventricles during ventricular diastole. |
What happens to the remaining 30% of the blood? | The active contraction of the atria propels the remaining 30% of the blood into the ventricles. |
What happens during periods of ventricular relaxation? | Cardiac filling and coronary perfusion occur passively. |
How often does one (1) cardiac cyle occur? | One (1) cardiac cyle occurs every 0.8 seconds. |
How long does systole last? | Systole lasts about 0.28 seconds. |
How long does diastole last? | Diastole lasts about 0.52 seconds. |
What is stroke volume? | Stroke volume is the volume of blood pumped out of one ventricle of the heart in a single beat or contraction. |
How much stroke volume occurs per beat? | 70 cc (cubic centimeters or millileters) per beat |
What is the definition of heart rate? | The heart rate is the number of contractions (or beats) per minute of the heart. |
What is the normal adult heart rate? | The normal adult heart rate is 60 - 100 beats per minute. |
What is the amount of blood pumped by the left ventricle in 1 minute? | Cardiac output is the amount of blood pumped by the left ventricle in 1 minute. |
True or False: Ventricle outputs are considered normally equal. ... and why? | True - because the ventricles contract simultaneously. |
What is the formula for determining cardiac output? | Cardiac Output (CO) = Stroke Volume (SV) x Heart Rate (HR) |
What happens when a patients cardiac output is outside of the normal range? | When a patients cardiac output is outside the normal range, the heart will try to balance it by changes in either the stroke volume or the heart rate. |
Based on the formula, what is the cardiac output for a patient who has 80 beats per minute (bpm) and a stroke volume of 70 cc per beat? | The cardiac output is 5600 cc per minute (or 5.6 liters per minute). |
What is the pressure in the ventricles at the end of diastole? | Preload |
What is the resistance against which the heart must pump? | Afterload |
What is Starling's law of the heart? | The more the myocardial fibers are stretched, up to a certain point, the more forceful the subsequent contraction. |
What is the amount of opposition to blood flow offered by the arterioles? | Peripheral vascular resistance (PVR) |
What determines peripheral vascular resistance? | Vasoconstriction and vasodilation |
What is the formula to determine blood pressure? | Blood pressure (BP) = Cardiac Output (CO) x Peripheral Vascular Resistance (PVR) |
What does the autonomic nervous system regulate? | The autonomic nervous system regulates functions of the body that are involuntary or not under conscious control. |
What is the sympathetic nervous system responsible for? | The sympathetic nervous system is responsible for preparation of the body for physical activity (i.e. "fight or flight") |
What is the built-in control center for the body that maintains homeostatis or equalibrium? | The autonomic nervous system. |
What are the two divisions of the autonomic nervous system? | The two divisions of the autonomic nervous system are the sympathetic and parasympathetic nervous system. |
What is the definition of innervate? | To supply (an organ or a body part) with nerves |
What is innervated by both the sympathetic and parasympathetic nervous system? | The majority of organs |
What is ONLY innervated by the sympathetic nervous system? | Blood vessels |
What portion of our body is regulated by the calmer functions (rest and digest) of our existence? Hint: It is a system. | Parasympathetic nervous system |
What is secreted from the nerve endings of the sympathetic and parasympathetic nervous systems? | Neurotransmitters are secreted from the nerve endings of the sympathetic and parasympathetic nervous systems. |
How many types of receptor fibers are located at the nerve endings in the sympathetic nervous system? | Two (2) |
What are the two receptor fibers at the nerve endings in the sympathetic nervous system? | The receptors are the alpha- and beta-receptors. |
What is the chemical neurotransmitter for the sympathetic nervous system? | Norepinephrine |
What is the chemical neurotransmitter for the parasympathetic nervous system? | Acetylcholine |
The nerve endings in the sympathetic nervous system are called ____________. | Adrenergic |
What happens in the sympathetic nervous system when norepinephrine is released? | The heart rate increases and contractile force of cardiac fibers and vasoconstriction will result. |
What is the chemical neurotransmitter for the parasympathetic nervous system? | Acetylecholine |
What are the nerve endings in the parasympathetic nervous system? | Cholinergic |
All the body's blood vessels have alpha-adrenergic receptors except _____________. | Capillaries |
What kind of receptors does the heart and lungs have? | The heart and lungs have beta-adrenergic receptors. |
What is the definition of vaso? | Vaso = Blood vessel |
What pertains to the sympathetic nerve fibers of the autonomic nervous system that use epinephrine or epinephrine-like (norepinephrine) substances as neurotransmitters? | Adrenergic |
What reactive site on the cell surface or within the cell combines with a drug molecule to produce a physiological effect? | Receptor |
What pertains to the parasympathetic nerve fibers of the autonomic nervous system that use acetylcholine as the neurotransmitter? | Cholinergic |
What is caused by vasoconstriction? | An increase in blood pressure |
What is caused by beta 1 receptors? | 1. Increase in Heart Rate2. Increase in contractility |
What is caused by beta 2 receptors? | 1. Bronchial dilation2. Vasodilation |
Pertaining to the adrenergic receptors and their effects on heart rate, what does A B C D stand for? | A B C D = Alpha Constricts Beta Dilates |