I think it 700 million years because I took the same question and that’s what I put.
the autonomic (involuntary) nervous system controls the rate at which the heartbeats. sympathetic (fight or flight) signals speed up the heart’s rate while parasympathetic (rest and digest) signals slow it down. The part or parts of the heart that forms sympathetic and parasympathetic neurons form synapses is called cardiac plexus.
Cardiac plexus is a plexus of the nerves that are present at the base of the heart and is divided into superficial and deep part. The sympathetic and the parasympathetic nerves form synapses with heart in the form of cardiac plexus.
The sympathetic nerves are responsible for activating flight or fight mode while parasympathetic nerves are responsible for restoring the normal body state.
To learn more about sympathetic nerves here
brainly.com/question/7495218
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The distinguishing characteristics of the free living members of sarcodina are:
1. These are pseudopods (function in locomotion) which makes it the extentions of protoplasm.
2. These have both a clear ectoplasm and a granualated endoplasm.
3. These have nucleus both food vacuoles and contractile vacuoles.