Sympathetic Division

Definition

The sympathetic division is a part of the autonomic nervous system responsible for the body's 'fight or flight' response, preparing the body for stressful situations. It activates various physiological changes, such as increasing heart rate and redirecting blood flow to essential muscles, which enhances alertness and readiness. This division works alongside the parasympathetic division, which promotes rest and digestion, creating a balance in how the body responds to different stimuli.

5 Must Know Facts For Your Next Test

1. The sympathetic division originates from the thoracic and lumbar regions of the spinal cord, often referred to as the thoracolumbar outflow.
2. When activated, this division causes dilation of pupils, increased heart rate, and bronchodilation to enhance airflow to the lungs.
3. Sympathetic responses can lead to temporary inhibition of non-essential functions like digestion to prioritize resources for immediate survival.
4. Stress hormones like adrenaline are released during sympathetic activation, which further amplifies the body's preparedness for action.
5. The sympathetic division works in tandem with the parasympathetic division to ensure homeostasis by balancing reactions to internal and external stimuli.

Review Questions

• How does the sympathetic division interact with other parts of the nervous system to prepare the body for stress?
  • The sympathetic division interacts with various components of the autonomic nervous system by activating responses that prepare the body for stress. When faced with a threat, it sends signals through nerve pathways originating in the spinal cord, resulting in increased heart rate and blood flow to muscles. This activation works alongside sensory inputs that alert the brain, making it crucial for a coordinated response during emergencies.
• Discuss the physiological changes that occur when the sympathetic division is activated and their significance in survival.
  • When the sympathetic division is activated, several physiological changes occur: pupils dilate for better vision, heart rate increases to pump more blood, and airways expand to improve oxygen intake. These changes are significant because they prepare an individual to respond quickly to threats—essentially enabling a 'fight or flight' response. This quick reaction can mean the difference between safety and danger in critical situations.
• Evaluate how chronic activation of the sympathetic division can affect overall health and well-being.
  • Chronic activation of the sympathetic division can lead to detrimental health effects such as hypertension, increased anxiety, and digestive issues due to prolonged stress responses. Over time, continuous exposure to high levels of stress hormones can impair bodily functions and lead to serious health problems like heart disease or gastrointestinal disorders. Understanding these impacts emphasizes the importance of stress management techniques to maintain balance between sympathetic and parasympathetic activities for overall well-being.

Related terms

Autonomic Nervous System:

A self-regulating system that controls involuntary bodily functions, including heart rate, digestion, and respiratory rate.

Parasympathetic Division:

The part of the autonomic nervous system that promotes 'rest and digest' activities, helping to conserve energy and promote relaxation.

Neurotransmitters:

Chemical messengers used by the nervous system to transmit signals between neurons, including those that mediate the effects of the sympathetic division.