A primary reason for needing a new vaccine for influenza each year is that there could be mutation of surface proteins leading to a new outbreak
<h3>What is antigenic drift?</h3>
Antigenic drift is a phenomenon that causes small changes or mutations in the genes of influenza viruses leading to changes in their surface proteins of the virus, which are HA (hemagglutinin) and NA (neuraminidase).
For this reason, new influenza vaccines are produced yearly to alter the effects that may emerge as a result.
Thus, a primary reason for needing a new vaccine for influenza each year is that there could be mutation of surface proteins leading to a new outbreak
Learn more about influenza here:
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Answer: 1. Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.
2. Plasma is the main component of blood and consists mostly of water, with proteins, ions, nutrients, and wastes mixed in. Red blood cells are responsible for carrying oxygen and carbon dioxide. Platelets are responsible for blood clotting. White blood cells are part of the immune system and function in immune response.
3.Within the bone marrow, all blood cells originate from a single type of unspecialized cell called a stem cell. When a stem cell divides, it first becomes an immature red blood cell, white blood cell, or platelet-producing cell.
4. Epinephrine and norepinephrine, hormones secreted by the adrenal medulla, raise blood pressure by increasing heart rate and the contractility of the heart muscles and by causing vasoconstriction of arteries and veins. These hormones are secreted as part of the fight‐or‐flight response.
 
        
             
        
        
        
Answer:
The correct answer will be option B-left atrium.
Explanation:
The coronary circulation is the circulation of blood and nutrients to the myocardium of the heart on both sides.
The coronary system consists of coronary arteries and coronary sinus(vein) in which coronary arteries arise from the main artery of the circulatory system called aorta. This aorta arises from the left atrium of the heart which supplies oxygenated blood. These coronary arteries divide into left and right arteries which supply oxygenated blood to the heart.
Thus, option B-left atrium is the correct answer.
 
        
             
        
        
        
Answer:
The most likely diagnosis would be ulcerative colitis, given the patient's history of regional enteritis and the finding of dark blood at the level of the sigmoidoscope.
<u><em>Do not use this as a medical diagnosis, consult a professional.</em></u>
 
        
             
        
        
        
Answer: (A) Hyperal dosteronism
Explanation:
In the case of hyperaldosteronism the levels of secretion of aldosterone increases. This can become responsible for alkolosis and hyperkalemia. High blood pressure, low levels of potassium, headache, muscle weakness, numbness and feeling tired are the symptoms of the hyper dosteronism. Also the increase in the content of sodium and decrease in levels of magnesium causes polyuria and polydipsia without causing polyphagia.