4 is the correct answer hope you get it right!!!
Water! (abiotic)
If water runs out then everything dies! :)
Thanks for the opportunity to answer your question and I hope this help! :)
The total blockade comes with the biggest potentially fatal complication of an epidural or intrathecal anesthesia. Many women choose this type of spinal epidural or intrathecal anesthesia during labor to block all labor pains. The primary symptom is hypotension. Hypotension is low blood pressure. Nausea is usually the first symptom of hypotension. A nurse will be able to intervene when the vital machine shows the blood pressure dropping. This why hospitals always have someone connected throughout labor to a vital signs machine when having an epidural or intrathecal anesthesia.
The right atrium receives blood returning from others parts of the body through the superior vena cava and the inferior vena cava.
Explanation:
The pathway of circulation begins in the right atrium which receives the carbon dioxide-rich deoxygenated blood returning through the systemic circulation.
The deoxygenated blood from regions superior to the heart, i.e., the head, neck, shoulder areas are collected through the superior vena cava and that from the parts inferior or lower to the heart like visceral organs, extremities, trunk, hip etc are brought through the inferior vena cava.
Both these venous systems (superior and inferior) fill the right atrium.
The right atrium then pumps the deoxygenated blood to the right ventricle via the tricuspid valve.
The right atrium is filled with blood during diastole.