autonomic function from higher cortical regions


Why sudden fear or emotion can sometimes cause vagal activation leading to bradycardia but fear and anxiety can lead to sympathetic activation that cause tachycardia, increased inotropy and hypertension?

And y chronic sympathetic activation induced by long-term emotional stress can result in sustained hypertension, cardiac hypertrophy, and arrhythmias?

Many thanks for any reply.


1 Article; 2,188 Posts

Specializes in Home Care.

What does your text book say? Did you research this ?


3 Posts

What does your text book say? Did you research this ?

There are only brief introduction in text book for this and so I am just curious about the contents when read here. Actually my research direction is relevant to cardiovascular field that involved in physiology knowledge of other parts of human body.

Anne36, LPN

1,360 Posts

Does this have to do with the fact that the Hypothalamus lies at the heart of the Limbic system? ( the emotional part of the brain) also, the Hypothalamus is the main visceral control center of the body.(autonomic control) regulates, cardiac and smooth muscel, heart rate, blood pressure, etc. The Hypothalamus works thru the ANS to initiate most physical expressions of emotion. The amygdala (fear) may be expressed through the hypothalamus because that is where most Limbic system output is relayed.

Sorry if that didnt help.

Anne36, LPN

1,360 Posts

Im not a Nursing student, only in A&P 1. This stuff is fresh in my head from the last exam.