Sorry if I’m wrong but I believe it’s the cardiovascular and lymphatic system
Hope this helps!
Answer: the correct answer is d. all of the above must happen for defecation to occur.
Explanation:
In response to the distention of the rectal wall, the receptors send sensory nerve impulses to the sacral spinal cord. Motor impulses from the cord travel along parasympathetic nerves back to the descending colon, sigmoid colon, rectum, and anus. The resulting contraction of the longitudinal rectal muscles shortens the rectum, thereby increasing the pressure within it. This then opens the internal sphincter.
Muscle cells extended called nervous muscle fibre tissue unit of muscle fiber
The best and most correct answer among the choices provided by your question is the first choice or letter A.
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An advantage of electron microscopes compared to light microscopes is that electron microscopes allow you to view living cells, while light microscopes do not.</span>
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