Answer:
Lumen corresponds to the central opening of a vessel (option d).
Explanation:
From the biological point of view, lumen is the internal space of any structure or tubular organ, whose purpose is the conduction of substances through it.
In the case of blood vessels, the lumen is a central space covered by a simple epithelium, called the endothelium, which ensures the passage of blood in a fluid form.
The other options do not correspond to the answer:
<em> a. </em><u><em>Vessel that empties into the right atrium</em></u><em> is the vena cava</em>
<em> b. </em><u><em>Fibrous sac around the heart </em></u><em>is the pericardium.
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<em> c. </em><u><em>Structure that keeps fluid moving forward</em></u><em>, it is a blood vessel.
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<em> e. </em><u><em>Lower, pointed region of the heart</em></u><em>, corresponds to the cardiac apex.</em>
The fight-or-flight response is associated with the release of acetylcholine. uric acid, and lymphocytes. epinephrine. teratogens. into the bloodstream.
Answer:
Masks haven't impacted schools, however social distancing has, as there's only so many people that can fit within one classroom, therefore most schools have switched to a hybrid schedule, making it so that people have to go to school at different times.
Explanation:
