Veterinary Technician - Cardiovascular Pharmacology

Crystalloids are a type of intravenous fluid that contain water and various electrolytes. They are commonly used in medical settings to replace lost fluids and electrolytes, such as in cases of dehydration or blood loss. Crystalloids can also be used for daily maintenance of electrolyte levels in patients who are unable to consume fluids orally. Therefore, the statement that crystalloids are used to either replace electrolytes or for daily maintenance of electrolytes is true.

The correct answer is Catecholamines, Cardiac Glycosides, Phosphodiesterase Inhibitors. Positive inotropes are medications that increase the force of contraction of the heart muscle. Catecholamines, such as epinephrine and dopamine, stimulate the beta-adrenergic receptors in the heart, leading to increased contractility. Cardiac glycosides, like digoxin, inhibit the sodium-potassium ATPase pump, resulting in increased intracellular calcium levels and improved contractility. Phosphodiesterase inhibitors, such as milrinone, inhibit the breakdown of cyclic adenosine monophosphate (cAMP), leading to increased calcium concentration and enhanced contractility. Beta-blockers and calcium channel blockers are negative inotropes, meaning they decrease the force of contraction.

Beta-blockers are a type of medication that work by blocking the effects of adrenaline on the heart. By doing so, they can help lower heart rate. Adrenaline is a hormone that increases heart rate and blood pressure, so by blocking its effects, beta-blockers can slow down the heart rate. This can be beneficial for individuals with high blood pressure, heart disease, or certain heart rhythm disorders.

Isotonic solutions contain approximately 300 mOsm. This means that the concentration of solutes in the solution is equal to the concentration of solutes in the cells or tissues with which it is in contact. This balance of solute concentration helps to maintain normal cell function and prevent osmotic imbalances.

For daily maintenance on crystalloids, the correct answer is low Na and high K. This is because crystalloids are fluids that are used to replenish electrolytes and maintain hydration in the body. Sodium (Na) is an important electrolyte that helps regulate fluid balance, but excessive sodium intake can lead to fluid retention and high blood pressure. On the other hand, potassium (K) is necessary for proper muscle and nerve function, and a deficiency can cause muscle weakness and abnormal heart rhythms. Therefore, for daily maintenance, it is recommended to have a lower sodium content and higher potassium content in crystalloids to maintain a healthy electrolyte balance.

For replacement of fluids and electrolytes with crystalloids, it is important to have a solution that contains a high concentration of sodium (Na) and a low concentration of potassium (K). This is because sodium plays a crucial role in maintaining fluid balance and helps in the functioning of nerves and muscles. On the other hand, potassium is essential for maintaining proper heart function and muscle contractions. Therefore, a solution with high sodium and low potassium would be ideal for replenishing fluids and electrolytes effectively.

Class 1 anti-arrhythmic drugs block NA gates, which slows down the depolarization of the cardiac cells. This helps to stabilize the electrical activity of the heart and prevent abnormal heart rhythms or arrhythmias. By blocking the sodium channels, these drugs decrease the conduction of electrical signals in the heart, which can be beneficial in treating certain types of arrhythmias.

Animals do not show signs of right-sided Congestive Heart Failure through pulmonary edema and coughing. Instead, these symptoms are associated with left-sided Congestive Heart Failure. In right-sided heart failure, animals typically exhibit symptoms such as abdominal distension, fluid accumulation in the legs or paws, and fatigue.

Hypotonic solutions have a lower osmotic concentration compared to the surrounding environment or another solution. In this case, a concentration of less than 300mOsm is considered hypotonic.

ACE-Inhibitors cannot be used as a positive chronotrope because they work by inhibiting the action of angiotensin-converting enzyme, which ultimately leads to vasodilation and decreased blood pressure. They do not directly affect heart rate or cardiac contractility, which are the characteristics of positive chronotropes. Positive chronotropes, such as beta-blockers and muscarinic cholinoceptor antagonists, increase heart rate and contractility, while an electronic pacemaker can regulate the heart rate.

Low-Dose Dopamine is not used as a vasopressor because it primarily acts as a renal vasodilator at low doses, rather than a vasoconstrictor. It increases renal blood flow and urine output, making it more suitable for treating certain types of renal failure rather than hypotension. Epinephrine, High-Dose Dopamine, and Ephedrine are all commonly used as vasopressors to increase blood pressure and constrict blood vessels.

Fresh plasma is the correct answer because it is a component of whole blood and fractionated blood. Whole blood consists of red blood cells, white blood cells, platelets, and plasma. Fractionated blood refers to the separation of whole blood into its components, including packed red blood cells, concentrated platelets, and fresh plasma. Therefore, fresh plasma is not excluded from whole or fractionated blood.

Systemic hypertension refers to high blood pressure throughout the body. Acute trauma, such as a severe injury or accident, can cause an increase in blood pressure due to the body's stress response. This response involves the release of stress hormones, which can lead to vasoconstriction and an increase in heart rate, resulting in elevated blood pressure. Long term drug use, blood loss, and cold weather are not typically direct causes of systemic hypertension.

Class 3 antiarrhythmic drugs produce their effects by prolonging an action potential. These drugs work by blocking potassium channels in cardiac cells, which slows down the repolarization phase of the action potential. By prolonging the action potential, these drugs help to restore normal rhythm in the heart and prevent arrhythmias.