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>
Water is constantly moving in cycle between the atmosphere and soil.
That answer is in fact true.
A higher resting heart rate means that your metabolism is higher (you burn more calories resting than the average person). This is the opposite for a slower resting heart rate, which means your metabolism is lower and less calories are burned resting.
Answer:
B or D
Explanation:this question is confusing me lol
The heart is part of the cardiovascular system. This system acts as a “railway”, and delivers blood and oxygen to the rest of the body.
