A patient's heart rate increases, pupils dilate, and blood is redirected to skeletal muscles. Which branch of the nervous system is primarily responsible?
ASomatic division
BParasympathetic division
CSympathetic division
DEnteric division
These are classic 'fight-or-flight' responses driven by the sympathetic branch of the autonomic nervous system. The sympathetic system mobilizes the body's resources for action: increasing heart rate, dilating pupils to improve vision, and shunting blood to muscles. The parasympathetic branch produces opposite effects (slowed heart rate, constriction of pupils) under 'rest-and-digest' conditions.
Question 2 True / False
The sympathetic nervous system is mainly active during emergencies and fight-or-flight situations.
TTrue
FFalse
Answer: False
This is a common misconception. The sympathetic nervous system provides tonic (continuous baseline) regulation of many functions including blood pressure, body temperature, and vascular tone — even when you are sitting still. It is not an on/off emergency switch; rather, both sympathetic and parasympathetic branches are always active, with their relative balance shifting depending on the body's needs.
Question 3 Short Answer
What is the functional distinction between the somatic and autonomic divisions of the peripheral nervous system?
Think about your answer, then reveal below.
Model answer: The somatic division controls voluntary skeletal muscle movement and carries conscious sensory information; the autonomic division regulates involuntary functions of visceral organs (heart, smooth muscle, glands) without conscious control.
This distinction maps onto conscious vs. unconscious control. You can decide to raise your arm (somatic) but cannot directly decide to speed up your heart rate (autonomic). The autonomic division maintains the internal environment homeostasis that you rely on without thinking about it.